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Culture, History, Evolution, and General Interest
(The following additional keywords have been used
to categorize articles within this section and may assist your search.)
culture, history; domestic species, domestication,
evolution, general interest, hyrax, Hyracoidea, mammoth, mastodon,
phylogeny, pygmy elephant, Sirenia
Elephant
Bibliographic
Database
www.elephantcare.org
References updated October 2009 by date of publication, most recent
first.
Cerling, T.E.,
Wittemyer, G., Ehleringer, J.R., Remien, C.H., Douglas-Hamilton, I.,
2009. History of Animals using Isotope Records (HAIR): a 6-year dietary
history of one family of African elephants
76. Proc. Natl. Acad. Sci. U. S. A 106, 8093-8100.
Abstract: The dietary and movement history of individual animals can be
studied using stable isotope records in animal tissues, providing
insight into long-term ecological dynamics and a species niche. We
provide a 6-year history of elephant diet by examining tail hair
collected from 4 elephants in the same social family unit in northern
Kenya. Sequential measurements of carbon, nitrogen, and hydrogen isotope
rations in hair provide a weekly record of diet and water resources.
Carbon isotope ratios were well correlated with satellite-based
measurements of the normalized difference vegetation index (NDVI) of the
region occupied by the elephants as recorded by the global positioning
system (GPS) movement record; the absolute amount of C(4) grass
consumption is well correlated with the maximum value of NDVI during
individual wet seasons. Changes in hydrogen isotope ratios coincided
very closely in time with seasonal fluctuations in rainfall and NDVI
whereas diet shifts to relatively high proportions of grass lagged
seasonal increases in NDVI by approximately 2 weeks. The peak
probability of conception in the population occurred approximately 3
weeks after peak grazing. Spatial and temporal patterns of resource use
show that the only period of pure browsing by the focal elephants was
located in an over-grazed, communally managed region outside the
protected area. The ability to extract time-specific longitudinal
records on animal diets, and therefore the ecological history of an
organism and its environment, provides an avenue for understanding the
impact of climate dynamics and land-use change on animal foraging
behavior and habitat relations
Clark, C.J.,
Poulsen, J.R., Malonga, R., Elkan, P.W., Jr., 2009. Logging concessions
can extend the conservation estate for Central African tropical forests
56. Conserv. Biol. 23, 1281-1293.
Abstract: The management of tropical forest in timber concessions has
been proposed as a solution to prevent further biodiversity loss. The
effectiveness of this strategy will likely depend on species-specific,
population-level responses to logging. We conducted a survey (749 line
transects over 3450 km) in logging concessions (1.2 million ha) in the
northern Republic of Congo to examine the impact of logging on large
mammal populations, including endangered species such as the elephant
(Loxodonta africana), gorilla (Gorilla gorilla), chimpanzee (Pan
troglodytes), and bongo (Tragelaphus eurycerus). When we estimated
species abundance without consideration of transect characteristics,
species abundances in logged and unlogged forests were not different for
most species. When we modeled the data with a hurdle model approach,
however, analyzing species presence and conditional abundance separately
with generalized additive models and then combining them to calculate
the mean species abundance, species abundance varied strongly depending
on transect characteristics. The mean species abundance was often
related to the distance to unlogged forest, which suggests that intact
forest serves as source habitat for several species. The mean species
abundance responded nonlinearly to logging history, changing over 30
years as the forest recovered from logging. Finally the distance away
from roads, natural forest clearings, and villages also determined the
abundance of mammals. Our results suggest that logged forest can extend
the conservation estate for many of Central Africa's most threatened
species if managed appropriately. In addition to limiting hunting,
logging concessions must be large, contain patches of unlogged forest,
and include forest with different logging histories
Freeman,
E.W., Guagnano, G., Olson, D., Keele, M., Brown, J.L., 2009. Social
factors influence ovarian acyclicity in captive African elephants
(Loxodonta africana). Zoo. Biol. 28, 1-15.
Abstract: Nearly one-third of reproductive age African elephants in
North America that are hormonally monitored fail to exhibit estrous
cycle activity, which exacerbates the nonsustainability of the captive
population. Three surveys were distributed to facilities housing female
African elephants to determine how social and environmental variables
contribute to cyclicity problems. Forty-six facilities returned all
three surveys providing information on 90% of the SSP population and 106
elephants (64 cycling, 27 noncycling and 15 undetermined). Logistic
analyses found that some physiological and social history variables were
related to ovarian acyclicity. Females more likely to be acyclic had a
larger body mass index and had resided longer at a facility with the
same herdmates. Results suggest that controlling the weight of an
elephant might be a first step to helping mitigate estrous cycle
problems. Data further show that transferring females among facilities
has no major impact on ovarian activity. Last, social status appears to
impact cyclicity status; at 19 of 21 facilities that housed both cycling
and noncycling elephants, the dominant female was acyclic. Further
studies on how social and environmental dynamics affect hormone levels
in free-living, cycling elephants are needed to determine whether
acyclicity is strictly a captivity-related phenomenon
Fulka, J.,
Jr., Loi, P., Ptak, G., Fulka, H., John, J.S., 2009. Hope for the
mammoth? Cloning Stem Cells 11, 1-4.
Gheerbrant,
E., 2009. Paleocene emergence of elephant relatives and the rapid
radiation of African ungulates
43. Proc. Natl. Acad. Sci. U. S. A 106, 10717-10721.
Abstract: Elephants are the only living representatives of the
Proboscidea, a formerly diverse mammalian order whose history began with
the 55-million years (mys) old Phosphatherium. Reported here is the
discovery from the early late Paleocene of Morocco, ca. 60 mys, of the
oldest and most primitive elephant relative, Eritherium azzouzorum n.g.,
n.sp., which is one of the earliest known representatives of modern
placental orders. This well supported stem proboscidean is
extraordinarily primitive and condylarth-like. It provides the first
dental evidence of a resemblance between the proboscideans and African
ungulates (paenungulates) on the one hand and the louisinines and early
macroscelideans on the other. Eritherium illustrates the origin of the
elephant order at a previously unknown primitive stage among
paenungulates and "ungulates." The primitive morphology of Eritherium
suggests a recent and rapid paenungulate radiation after the
Cretaceous-Tertiary boundary, probably favoured by early endemic African
paleoecosystems. At a broader scale, Eritherium provides a new old
calibration point of the placental tree and supports an explosive
placental radiation. The Ouled Abdoun basin, which yields the oldest
known African placentals, is a key locality for elucidating phylogeny
and early evolution of paenungulates and other related endemic African
lineages
Greenwald,
R., Lyashchenko, O., Esfandiari, J., Miller, M., Mikota, S., Olsen, J.H.,
Ball, R., Dumonceaux, G., Schmitt, D., Moller, T., Payeur, J.B., Harris,
B., Sofranko, D., Waters, W.R., Lyaschenko, K.P., 2009.
Highly accurate antibody assays for early and rapid detection of
tuberculosis in African and Asian elephants.
Clinical and Vaccine Immunology 16, 605-612.
Abstract:
Tuberculosis (TB) in elephants is a reemerging zoonotic disease caused
primarily by Mycobacterium tuberculosis. Current methods for screening
and diagnosis rely on trunk wash culture, which has serious limitations
due to low test sensitivity, slow turnaround time, and variable sample
quality. Innovative and more efficient diagnostic tools are urgently
needed. We describe three novel serologic techniques, the ElephantTB
Stat-Pak kit, multiantigen print immunoassay, and dual-path platform
VetTB test, for rapid antibody detection in elephants. The study was
performed with serum samples from 236 captive African and Asian
elephants from 53 different locations in the United States and Europe.
The elephants were divided into three groups based on disease status and
history of exposure: (i) 26 animals with culture-confirmed TB due to M.
tuberculosis or Mycobacterium bovis, (ii) 63 exposed elephants from
known-infected herds that had never produced a culture-positive result
from trunk wash samples, and (iii) 147 elephants without clinical
symptoms suggestive of TB, with consistently negative trunk wash culture
results, and with no history of potential exposure to TB in the past 5
years. Elephants with culture-confirmed TB and a proportion of exposed
but trunk wash culture-negative elephants produced robust antibody
responses to multiple antigens of M. tuberculosis, with seroconversions
detectable years before TB-positive cultures were obtained from trunk
wash specimens. ESAT-6 and CFP10 proteins were immunodominant antigens
recognized by elephant antibodies during disease. The serologic assays
demonstrated 100% sensitivity and 95 to 100% specificity. Rapid and
accurate antibody tests to identify infected elephants will likely allow
earlier and more efficient treatment, thus limiting transmission of
infection to other susceptible animals and to humans.
Greenwald,
R., Lyashchenko, O., Esfandiari, J., Miller, M., Mikota, S., Olsen, J.H.,
Ball, R., Dumonceaux, G., Schmitt, D., Moller, T., Payeur, J.B., Harris,
B., Sofranko, D., Waters, W.R., Lyashchenko, K.P., 2009. Highly accurate
antibody assays for early and rapid detection of tuberculosis in African
and Asian elephants. Clin. Vaccine Immunol. 16, 605-612.
Abstract: Tuberculosis (TB) in elephants is a reemerging zoonotic
disease caused primarily by Mycobacterium tuberculosis. Current methods
for screening and diagnosis rely on trunk wash culture, which has
serious limitations due to low test sensitivity, slow turnaround time,
and variable sample quality. Innovative and more efficient diagnostic
tools are urgently needed. We describe three novel serologic techniques,
the ElephantTB Stat-Pak kit, multiantigen print immunoassay, and
dual-path platform VetTB test, for rapid antibody detection in
elephants. The study was performed with serum samples from 236 captive
African and Asian elephants from 53 different locations in the United
States and Europe. The elephants were divided into three groups based on
disease status and history of exposure: (i) 26 animals with
culture-confirmed TB due to M. tuberculosis or Mycobacterium bovis, (ii)
63 exposed elephants from known-infected herds that had never produced a
culture-positive result from trunk wash samples, and (iii) 147 elephants
without clinical symptoms suggestive of TB, with consistently negative
trunk wash culture results, and with no history of potential exposure to
TB in the past 5 years. Elephants with culture-confirmed TB and a
proportion of exposed but trunk wash culture-negative elephants produced
robust antibody responses to multiple antigens of M. tuberculosis, with
seroconversions detectable years before TB-positive cultures were
obtained from trunk wash specimens. ESAT-6 and CFP10 proteins were
immunodominant antigens recognized by elephant antibodies during
disease. The serologic assays demonstrated 100% sensitivity and 95 to
100% specificity. Rapid and accurate antibody tests to identify infected
elephants will likely allow earlier and more efficient treatment, thus
limiting transmission of infection to other susceptible animals and to
humans
Grus, W.E., Zhang, J., 2009.
Origin of the
genetic components of the vomeronasal system in the common ancestor of
all extant vertebrates. Molecular Biology and Evolution 26,
407-419.
Abstract: Comparative genomics provides a valuable tool for inferring
the evolutionary history of physiological systems, particularly when
this information is difficult to ascertain by morphological traits. One
such example is the vomeronasal system (VNS), a vertebrate nasal
chemosensory system that is responsible for detecting intraspecific
pheromonal cues as well as environmental odorants. The morphological
components of the VNS are found only in tetrapods, but the genetic
components of the system have been found in teleost fish, in addition to
tetrapods. To determine when the genetic components of the VNS
originated, we searched for the VNS-specific genes in the genomes of two
early diverging vertebrate lineages: the sea lamprey from jawless fishes
and the elephant shark from cartilaginous fishes. Genes encoding
vomeronasal type 1 receptors (V1Rs) and Trpc2, two components of the
vomeronasal signaling pathway, are present in the sea lamprey genome,
and both are expressed in the olfactory organ, revealing that the
genetic components of the present-day VNS existed in the common ancestor
of all extant vertebrates. Additionally, all three VNS genes, Trpc2,
V1Rs, and vomeronasal type 2 receptors (V2Rs), are found in the elephant
shark genome. Because V1Rs and V2Rs are related to two families of taste
receptors, we also searched the early diverging vertebrate genomes for
taste system genes and found them in the shark genome but not in the
lamprey. Coupled with known distributions of the genetic components of
the vertebrate main olfactory system, our results suggest staggered
origins of vertebrate sensory systems. These findings are important for
understanding the evolution of vertebrate sensory systems and illustrate
the utility of the genome sequences of early diverging vertebrates for
uncovering the evolution of vertebrate-specific traits
Hakeem, A.Y.,
Sherwood, C.C., Bonar, C.J., Butti, C., Hof, P.R., Allman, J.M., 2009.
Von Economo neurons in the elephant brain. Anat. Rec. (Hoboken. ) 292,
242-248.
Abstract: Von Economo neurons (VENs), previously found in humans, all of
the great ape species, and four cetacean species, are also present in
African and Indian elephants. The VENs in the elephant are primarily
found in similar locations to those in the other species. They are most
abundant in the frontoinsular cortex (area FI) and are also present at
lower density in the anterior cingulate cortex. Additionally, they are
found in a dorsolateral prefrontal area and less abundantly in the
region of the frontal pole. The VEN morphology appears to have arisen
independently in hominids, cetaceans, and elephants, and may reflect a
specialization for the rapid transmission of crucial social information
in very large brains
Kaim, U.,
Paltian, V., Krudewig, C., Nieder, A., Wohlsein, P., 2009. Pulmonary
aspergillosis in an African elephant (Loxodonta africana)
64. Dtsch. Tierarztl. Wochenschr. 116, 148-151.
Abstract: A 26-year-old female African elephant (Loxodonta africana)
with a history of purulent pododermatitis, recurrent abdominal pain, and
severe weight loss died spontaneously after a period of deteriorating
disease. The main pathological finding was a severe bilateral
pyogranulomatous, partially necrotizing pneumonia with numerous
intralesional fungal hyphae. At microbiological examination Aspergillus
spp. were isolated. The present case indicates that mycotic pneumonia
should to be considered as a differential diagnosis of pulmonary
disorders in elephants
Kun, A.,
Scheuring, I., 2009.
Evolution of cooperation on dynamical graphs.
Biosystems 96, 65-68.
Abstract:
There are two key characteristics of animal and human societies: (1)
degree heterogeneity, meaning that not all individual have the same
number of associates; and (2) the interaction topology is not static,
i.e. either individuals interact with different set of individuals at
different times of their life, or at least they have different
associations than their parents. Earlier works have shown that
population structure is one of the mechanisms promoting cooperation.
However, most studies had assumed that the interaction network can be
described by a regular graph (homogeneous degree distribution). Recently
there are an increasing number of studies employing degree heterogeneous
graphs to model interaction topology. But mostly the interaction
topology was assumed to be static. Here we investigate the fixation
probability of the cooperator strategy in the prisoner's dilemma, when
interaction network is a random regular graph, a random graph or a
scale-free graph and the interaction network is allowed to change.We
show that the fixation probability of the cooperator strategy is lower
when the interaction topology is described by a dynamical graph compared
to a static graph. Even a limited network dynamics significantly
decreases the fixation probability of cooperation, an effect that is
mitigated stronger by degree heterogeneous networks topology than by a
degree homogeneous one. We have also found that from the considered
graph topologies the decrease of fixation probabilities due to graph
dynamics is the lowest on scale-free graphs.
Leshchinskiy,
S.V., 2009. Mineral deficiency, enzootic diseases and extinction of
mammoth of northern Eurasia
82. Dokl. Biol. Sci. 424, 72-74.
Mueller, T. A near-perfect frozen mammoth
resurfaces after 40,000 years, bearing clues to a great vanished species.
National Geographic [May]. 2009.
Ref Type: Magazine Article
Murata, Y.,
Yonezawa, T., Kihara, I., Kashiwamura, T., Sugihara, Y., Nikaido, M.,
Okada, N., Endo, H., Hasegawa, M., 2009. Chronology of the extant
African elephant species and case study of the species identification of
the small African elephant with the molecular phylogenetic method
70. Gene 441, 176-186.
Abstract: Despite vigorous genetic studies of African elephants
(Loxodonta africana and L. cyclotis) during the last decade, their
evolutionary history is still obscure. Phylogenetic studies and
coalescence time estimation using longer nucleotide sequence data from
denser samplings are necessary to better understand the natural history
of African elephants. Further, species identification among African
elephants is sometimes very difficult using only the external
morphological characteristics. This is a serious problem for making an
adequate breeding plan in zoological gardens. In this paper, we
investigated the continent-wide phylogeographical pattern of the African
elephants and estimated the coalescence times among them. From these
molecular data and geological evidence, we proposed an evolutionary
scenario for the African elephants. We further demonstrated the
effectiveness of molecular phylogenetic methods in species
identification.
Opazo, J.C.,
Sloan, A.M., Campbell, K.L., Storz, J.F., 2009. Origin and ascendancy of
a chimeric fusion gene: the beta/delta-globin gene of paenungulate
mammals
84. Molecular Biology and Evolution 26, 1469-1478.
Abstract: The delta-globin gene (HBD) of eutherian mammals exhibits a
propensity for recombinational exchange with the closely linked beta-globin
gene (HBB) and has been independently converted by the HBB gene in
multiple lineages. Here we report the presence of a chimeric beta/delta
fusion gene in the African elephant (Loxodonta africana) that was
created by unequal crossing-over between misaligned HBD and HBB paralogs.
The recombinant chromosome that harbors the beta/delta fusion gene in
elephants is structurally similar to the "anti-Lepore" duplication
mutant of humans (the reciprocal exchange product of the hemoglobin
Lepore deletion mutant). However, the situation in the African elephant
is unique in that the chimeric beta/delta fusion gene supplanted the
parental HBB gene and is therefore solely responsible for synthesizing
the beta-chain subunits of adult hemoglobin. A phylogenetic survey of
beta-like globin genes in afrotherian and xenarthran mammals revealed
that the origin of the chimeric beta/delta fusion gene and the
concomitant inactivation of the HBB gene predated the radiation of "Paenungulata,"
a clade of afrotherian mammals that includes three orders: Proboscidea
(elephants), Sirenia (dugongs and manatees), and Hyracoidea (hyraxes).
The reduced fitness of the human Hb Lepore deletion mutant helps to
explain why independently derived beta/delta fusion genes (which occur
on an anti-Lepore chromosome) have been fixed in a number of mammalian
lineages, whereas the reciprocal delta/beta fusion gene (which occurs on
a Lepore chromosome) has yet to be documented in any nonhuman mammal.
This illustrates how the evolutionary fates of chimeric fusion genes can
be strongly influenced by their recombinational mode of origin
Roca, A.L.,
Ishida, Y., Nikolaidis, N., Kolokotronis, S.O., Fratpietro, S.,
Stewardson, K., Hensley, S., Tisdale, M., Boeskorov, G., Greenwood,
A.D., 2009. Genetic variation at hair length candidate genes in
elephants and the extinct woolly mammoth. BMC. Evol. Biol. 9,
232.
Abstract: BACKGROUND: Like humans, the living elephants are unusual
among mammals in being sparsely covered with hair. Relative to extant
elephants, the extinct woolly mammoth, Mammuthus primigenius, had a
dense hair cover and extremely long hair, which likely were adaptations
to its subarctic habitat. The fibroblast growth factor 5 (FGF5) gene
affects hair length in a diverse set of mammalian species. Mutations in
FGF5 lead to recessive long hair phenotypes in mice, dogs, and cats; and
the gene has been implicated in hair length variation in rabbits. Thus,
FGF5 represents a leading candidate gene for the phenotypic differences
in hair length notable between extant elephants and the woolly mammoth.
We therefore sequenced the three exons (except for the 3' UTR) and a
portion of the promoter of FGF5 from the living elephantid species
(Asian, African savanna and African forest elephants) and, using
protocols for ancient DNA, from a woolly mammoth. RESULTS: Between the
extant elephants and the mammoth, two single base substitutions were
observed in FGF5, neither of which alters the amino acid sequence.
Modeling of the protein structure suggests that the elephantid proteins
fold similarly to the human FGF5 protein. Bioinformatics analyses and
DNA sequencing of another locus that has been implicated in hair cover
in humans, type I hair keratin pseudogene (KRTHAP1), also yielded
negative results. Interestingly, KRTHAP1 is a pseudogene in elephantids
as in humans (although fully functional in non-human primates).
CONCLUSION: The data suggest that the coding sequence of the FGF5 gene
is not the critical determinant of hair length differences among
elephantids. The results are discussed in the context of hairlessness
among mammals and in terms of the potential impact of large body size,
subarctic conditions, and an aquatic ancestor on hair cover in the
Proboscidea
Rodriguez
Delgado, C.L., Waters, P.D., Gilbert, C., Robinson, T.J., Graves, J.A.,
2009. Physical mapping of the elephant X chromosome: conservation of
gene order over 105 million years. Chromosome. Res.
Abstract: All therian mammals (eutherians and marsupials) have an XX
female/XY male sex chromosome system or some variant of it. The X and Y
evolved from a homologous pair of autosomes over the 166 million years
since therian mammals diverged from monotremes. Comparing the sex
chromosomes of eutherians and marsupials defined an ancient X conserved
region that is shared between species of these mammalian clades.
However, the eutherian X (and the Y) was augmented by a recent addition
(XAR) that is autosomal in marsupials. XAR is part of the X in primates,
rodents, and artiodactyls (which belong to the eutherian clade
Boreoeutheria), but it is uncertain whether XAR is part of the X
chromosome in more distantly related eutherian mammals. Here we report
on the gene content and order on the X of the elephant (Loxodonta
africana)-a representative of Afrotheria, a basal endemic clade of
African mammals-and compare these findings to those of other documented
eutherian species. A total of 17 genes were mapped to the elephant X
chromosome. Our results support the hypothesis that the eutherian X and
Y chromosomes were augmented by the addition of autosomal material prior
to eutherian radiation. Not only does the elephant X bear the same suite
of genes as other eutherian X chromosomes, but gene order appears to
have been maintained across 105 million years of evolution, perhaps
reflecting strong constraints posed by the eutherian X inactivation
system
Schwarz, C.,
Debruyne, R., Kuch, M., McNally, E., Schwarcz, H., Aubrey, A.D., Bada,
J., Poinar, H., 2009.
New insights from old bones: DNA preservation and degradation in
permafrost preserved mammoth remains.
Nucleic Acids Res March 24.
Schwarz, C.,
Debruyne, R., Kuch, M., McNally, E., Schwarcz, H., Aubrey, A.D., Bada,
J., Poinar, H., 2009. New insights from old bones: DNA preservation and
degradation in permafrost preserved mammoth remains
89. Nucleic Acids Res. 37, 3215-3229.
Abstract: Despite being plagued by heavily degraded DNA in
palaeontological remains, most studies addressing the state of DNA
degradation have been limited to types of damage which do not pose a
hindrance to Taq polymerase during PCR. Application of serial qPCR to
the two fractions obtained during extraction (demineralization and
protein digest) from six permafrost mammoth bones and one partially
degraded modern elephant bone has enabled further insight into the
changes which endogenous DNA is subjected to during diagenesis. We show
here that both fractions exhibit individual qualities in terms of the
prevailing type of DNA (i.e. mitochondrial versus nuclear DNA) as well
as the extent of damage, and in addition observed a highly variable
ratio of mitochondrial to nuclear DNA among the six mammoth samples.
While there is evidence suggesting that mitochondrial DNA is better
preserved than nuclear DNA in ancient permafrost samples, we find the
initial DNA concentration in the bone tissue to be as relevant for the
total accessible mitochondrial DNA as the extent of DNA degradation
post-mortem. We also evaluate the general applicability of indirect
measures of preservation such as amino-acid racemization, bone
crystallinity index and thermal age to these exceptionally
well-preserved samples
Sherwood,
C.C., Stimpson, C.D., Butti, C., Bonar, C.J., Newton, A.L., Allman, J.M.,
Hof, P.R., 2009. Neocortical neuron types in Xenarthra and Afrotheria:
implications for brain evolution in mammals. Brain Struct. Funct. 213,
301-328.
Abstract: Interpreting the evolution of neuronal types in the cerebral
cortex of mammals requires information from a diversity of species.
However, there is currently a paucity of data from the Xenarthra and
Afrotheria, two major phylogenetic groups that diverged close to the
base of the eutherian mammal adaptive radiation. In this study, we used
immunohistochemistry to examine the distribution and morphology of
neocortical neurons stained for nonphosphorylated neurofilament protein,
calbindin, calretinin, parvalbumin, and neuropeptide Y in three
xenarthran species-the giant anteater (Myrmecophaga tridactyla), the
lesser anteater (Tamandua tetradactyla), and the two-toed sloth (Choloepus
didactylus)-and two afrotherian species-the rock hyrax (Procavia
capensis) and the black and rufous giant elephant shrew (Rhynchocyon
petersi). We also studied the distribution and morphology of astrocytes
using glial fibrillary acidic protein as a marker. In all of these
species, nonphosphorylated neurofilament protein-immunoreactive neurons
predominated in layer V. These neurons exhibited diverse morphologies
with regional variation. Specifically, high proportions of atypical
neurofilament-enriched neuron classes were observed, including
extraverted neurons, inverted pyramidal neurons, fusiform neurons, and
other multipolar types. In addition, many projection neurons in layers
II-III were found to contain calbindin. Among interneurons, parvalbumin-
and calbindin-expressing cells were generally denser compared to
calretinin-immunoreactive cells. We traced the evolution of certain
cortical architectural traits using phylogenetic analysis. Based on our
reconstruction of character evolution, we found that the living
xenarthrans and afrotherians show many similarities to the stem
eutherian mammal, whereas other eutherian lineages display a greater
number of derived traits
Vidya, T.N.,
Sukumar, R., Melnick, D.J., 2009. Range-wide mtDNA phylogeography yields
insights into the origins of Asian elephants. Proc. Biol. Sci. 276,
893-902.
Abstract: Recent phylogeographic studies of the endangered Asian
elephant (Elephas maximus) reveal two highly divergent mitochondrial DNA
(mtDNA) lineages, an elucidation of which is central to understanding
the species's evolution. Previous explanations for the divergent clades
include introgression of mtDNA haplotypes between ancestral species,
allopatric divergence of the clades between Sri Lanka or the Sunda
region and the mainland, historical trade of elephants, and retention of
divergent lineages due to large population sizes. However, these studies
lacked data from India and Myanmar, which host approximately 70 per cent
of all extant Asian elephants. In this paper, we analyse mtDNA sequence
data from 534 Asian elephants across the species's range to explain the
current distribution of the two divergent clades. Based on phylogenetic
reconstructions, estimates of times of origin of clades, probable
ancestral areas of origin inferred from dispersal-vicariance analyses
and the available fossil record, we believe both clades originated from
Elephas hysudricus. This probably occurred allopatrically in different
glacial refugia, the alpha clade in the Myanmar region and the beta
clade possibly in southern India-Sri Lanka, 1.6-2.1Myr ago. Results from
nested clade and dispersal-vicariance analyses indicate a subsequent
isolation and independent diversification of the beta clade in both Sri
Lanka and the Sunda region, followed by northward expansion of the clade.
We also find more recent population expansions in both clades based on
mismatch distributions. We therefore suggest a contraction-expansion
scenario during severe climatic oscillations of the Quaternary, with
range expansions from different refugia during warmer interglacials
leading to the varying geographical overlaps of the two mtDNA clades. We
also demonstrate that trade in Asian elephants has not substantially
altered the species's mtDNA population genetic structure
Wallis, M.,
2009. Prolactin in the Afrotheria: characterization of genes encoding
prolactin in elephant (Loxodonta africana), hyrax (Procavia capensis)
and tenrec (Echinops telfairi). J. Endocrinol. 200, 233-240.
Abstract: Pituitary prolactin shows an episodic pattern of molecular
evolution, with occasional short bursts of rapid change imposed on a
generally rather slow evolutionary rate. In mammals, episodes of rapid
change occurred in the evolution of primates, cetartiodactyls, rodents
and the elephant. The bursts of rapid evolution in cetartiodactyls and
rodents were followed by duplications of the prolactin gene that gave
rise to large families of prolactin-related proteins including placental
lactogens, while in primates the burst was followed by corresponding
duplications of the related GH gene. The position in elephant is less
clear. Extensive data relating to the genomic sequences of elephant and
two additional members of the group Afrotheria are now available, and
have been used here to characterize the prolactin genes in these species
and explore whether additional prolactin-related genes are present. The
results confirm the rapid evolution of elephant (Loxodonta africana)
prolactin - the sequence of elephant prolactin is substantially
different from that predicted for the ancestral placental mammal. Hyrax
(Procavia capensis) prolactin is even more divergent but tenrec (Echinops
telfairi) prolactin is strongly conserved. No evidence was obtained from
searches of public databases for additional genes encoding
prolactin-like proteins in any of these species. Detailed analysis of
evolutionary rates, and other factors, indicates that the episode of
rapid change in hyrax, and probably elephant, was adaptive, though the
nature of the associated biological change(s) is not clear
Williams, A.C.,
Johnsingh, A.J.T., Krausman, P.R., 2009.
Population estimation and demography of the Rajaji National Park
elephants, Northwest India.
Journal of the Bombay Natural History Society 104, 142-152.
Abstract:
The Asian Elephant (Elephas maximus) population in Rajaji National Park,
north-west India is an important part of India's heritage, but has not
been intensively studied until recently. Understanding the population
dynamics is important for managers if the population is to remain
viable. We used marked adult male Asian Elephants in a mark re-sight
method to estimate the male segment of the population and the estimated
number of female and associated young using their proportions relative
to the adult male segment from classification data. We collected data on
inter-calving period and calf survival from adult females present in
groups with radio collared females. The number of adult males in the
study area was estimated to be 31 (95% CI = 23-41). We computed the
relative proportions of other age-sex classes to the adult males and
estimated 188 elephants (95% CI = 139-248). Ninety per cent of the adult
males had tusks (tuskers) and the adult male to adult female ratio was
1:1.87. This is one of the least skewed sex ratios reported for Asian
Elephants and is comparable to areas in Sri Lanka where 95% of males are
tuskless. Over 90% of the adult females were accompanied by juveniles or
calves <5 years old. We estimated the inter-calving period to be around
4.23 years and the calf survival over the first year was almost 100%.
One calf was killed when hit by a train. The high proportion of males,
low inter-calving period, and high neonate survival of the Rajaji
elephant population indicates that the population is demographically
healthy. However, more adult elephants died in train accidents than due
to natural causes and viability of this small population could be
seriously threatened if losses to train accidents continue.
Wittemyer,
G., Okello, J.B., Rasmussen, H.B., Arctander, P., Nyakaana, S.,
Douglas-Hamilton, I., Siegismund, H.R., 2009. Where sociality and
relatedness diverge: the genetic basis for hierarchical social
organization in African elephants. Proc Royal Soc Biol 276,
3513-3521.
Abstract: Hierarchical properties characterize elephant fission-fusion
social organization whereby stable groups of individuals coalesce into
higher order groups or split in a predictable manner. This hierarchical
complexity is rare among animals and, as such, an examination of the
factors driving its emergence offers unique insight into the evolution
of social behaviour. Investigation of the genetic basis for such social
affiliation demonstrates that while the majority of core social groups
(second-tier affiliates) are significantly related, this is not
exclusively the case. As such, direct benefits received through
membership of these groups appear to be salient to their formation and
maintenance. Further analysis revealed that the majority of groups in
the two higher social echelons (third and fourth tiers) are typically
not significantly related. The majority of third-tier members are
matrilocal, carrying the same mtDNA control region haplotype, while
matrilocality among fourth-tier groups was slightly less than expected
at random. Comparison of results to those from a less disturbed
population suggests that human depredation, leading to social
disruption, altered the genetic underpinning of social relations in the
study population. These results suggest that inclusive fitness benefits
may crystallize elephant hierarchical social structuring along genetic
lines when populations are undisturbed. However, indirect benefits are
not critical to the formation and maintenance of second-, third- or
fourth-tier level bonds, indicating the importance of direct benefits in
the emergence of complex, hierarchical social relations among elephants.
Future directions and conservation implications are discussed
Wong, K.,
2009. Decoding the mammoth
108. Scientific American 300, 26-27.
Asher, R.J.,
Lehmann, T., 2008. Dental eruption in afrotherian mammals. BMC. Biol. 6,
14.
Abstract: BACKGROUND: Afrotheria comprises a newly recognized clade of
mammals with strong molecular evidence for its monophyly. In contrast,
morphological data uniting its diverse constituents, including
elephants, sea cows, hyraxes, aardvarks, sengis, tenrecs and golden
moles, have been difficult to identify. Here, we suggest relatively late
eruption of the permanent dentition as a shared characteristic of
afrotherian mammals. This characteristic and other features (such as
vertebral anomalies and testicondy) recall the phenotype of a human
genetic pathology (cleidocranial dysplasia), correlations with which
have not been explored previously in the context of character evolution
within the recently established phylogeny of living mammalian clades.
RESULTS: Although data on the absolute timing of eruption in sengis,
golden moles and tenrecs are still unknown, craniometric comparisons for
ontogenetic series of these taxa show that considerable skull growth
takes place prior to the complete eruption of the permanent cheek teeth.
Specimens showing less than half (sengis, golden moles) or two-thirds (tenrecs,
hyraxes) of their permanent cheek teeth reach or exceed the median jaw
length of conspecifics with a complete dentition. With few exceptions,
afrotherians are closer to median adult jaw length with fewer erupted,
permanent cheek teeth than comparable stages of non-afrotherians.
Manatees (but not dugongs), elephants and hyraxes with known age data
show eruption of permanent teeth late in ontogeny relative to other
mammals. While the occurrence of delayed eruption, vertebral anomalies
and other potential afrotherian synapomorphies resemble some symptoms of
a human genetic pathology, these characteristics do not appear to covary
significantly among mammalian clades. CONCLUSION: Morphological
characteristics shared by such physically disparate animals such as
elephants and golden moles are not easy to recognize, but are now known
to include late eruption of permanent teeth, in addition to vertebral
anomalies, testicondy and other features. Awareness of their possible
genetic correlates promises insight into the developmental basis of
shared morphological features of afrotherians and other vertebrates
Aupperle, H.,
Reischauer, A., Bach, F., Hildebrandt, T., Goritz, F., Jager, K.,
Scheller, R., Klaue, H.J., Schoon, H.A., 2008. Chronic endometritis in
an Asian elephant (Elephas maximus). J. Zoo. Wildl. Med. 39,
107-110.
Abstract: A 48-yr-old female Asian elephant with a history of
pododermatitis developed recurrent hematuria beginning in 2002.
Transrectal ultrasonography and endoscopic examination in 2004
identified the uterus as the source of hematuria and excluded
hemorrhagic cystitis. Treatment with Desloreline implants, antibiotics,
and homeopathic drugs led to an improved general condition of the
elephant. In July 2005, the elephant was suddenly found dead. During
necropsy, the severely enlarged uterus contained about 250 L of purulent
fluid, and histopathology revealed ulcerative suppurative endometritis
with high numbers of Streptococcus equi ssp. zooepidemicus and
Escherichia coli identified on aerobic culture. Additional findings at
necropsy included: multifocal severe pododermatitis, uterine leiomyoma,
and numerous large calcified areas of abdominal fat necrosis.
Microbiologic culture of the pododermatitis lesion revealed the presence
of Streptococcus agalactiae, Streptococcus equi ssp. zooepidemicus,
Staphylococcus sp., Corynebacterium sp., and Entercoccus sp
Gilbert, M.T.,
Drautz, D.I., Lesk, A.M., Ho, S.Y., Qi, J., Ratan, A., Hsu, C.H., Sher,
A., Dalen, L., Gotherstrom, A., Tomsho, L.P., Rendulic, S., Packard, M.,
Campos, P.F., Kuznetsova, T.V., Shidlovskiy, F., Tikhonov, A.,
Willerslev, E., Iacumin, P., Buigues, B., Ericson, P.G., Germonpre, M.,
Kosintsev, P., Nikolaev, V., Nowak-Kemp, M., Knight, J.R., Irzyk, G.P.,
Perbost, C.S., Fredrikson, K.M., Harkins, T.T., Sheridan, S., Miller,
W., Schuster, S.C., 2008. Intraspecific phylogenetic analysis of
Siberian woolly mammoths using complete mitochondrial genomes. Proc.
Natl. Acad. Sci. U. S. A 105, 8327-8332.
Abstract: We report five new complete mitochondrial DNA (mtDNA) genomes
of Siberian woolly mammoth (Mammuthus primigenius), sequenced with up to
73-fold coverage from DNA extracted from hair shaft material. Three of
the sequences present the first complete mtDNA genomes of mammoth clade
II. Analysis of these and 13 recently published mtDNA genomes
demonstrates the existence of two apparently sympatric mtDNA clades that
exhibit high interclade divergence. The analytical power afforded by the
analysis of the complete mtDNA genomes reveals a surprisingly ancient
coalescence age of the two clades, approximately 1-2 million years,
depending on the calibration technique. Furthermore, statistical
analysis of the temporal distribution of the (14)C ages of these and
previously identified members of the two mammoth clades suggests that
clade II went extinct before clade I. Modeling of protein structures
failed to indicate any important functional difference between genomes
belonging to the two clades, suggesting that the loss of clade II more
likely is due to genetic drift than a selective sweep
Hofreiter,
M., 2008. DNA sequencing: Mammoth genomics. Nature 456, 330-331.
Huang, S.,
2008. Ancient fossil specimens of extinct species are genetically more
distant to an outgroup than extant sister species are. Riv. Biol. 101,
93-108.
Abstract: There exists a remarkable correlation between genetic distance
as measured by protein or DNA dissimilarity and time of species
divergence as inferred from fossil records. This observation has
provoked the molecular clock hypothesis. However, data inconsistent with
the hypothesis have steadily accumulated in recent years from studies of
extant organisms. Here the published DNA and protein sequences from
ancient fossil specimens were examined to see if they would support the
molecular clock hypothesis. The hypothesis predicts that ancient
specimens cannot be genetically more distant to an outgroup than extant
sister species are. Also, two distinct ancient specimens cannot be
genetically more distant than their extant sister species are. The
findings here do not conform to these predictions. Neanderthals are more
distant to chimpanzees and gorillas than modern humans are. Dinosaurs
are more distant to frogs than extant birds are. Mastodons are more
distant to opossums than other placental mammals are. The genetic
distance between dinosaurs and mastodons is greater than that between
extant birds and mammals. Therefore, while the molecular clock
hypothesis is consistent with some data from extant organisms, it has
yet to find support from ancient fossils. Far more damaging to the
hypothesis than data from extant organisms, which merely question the
constancy of mutation rate, the study of ancient fossil organisms here
challenges for the first time the fundamental premise of modern
evolution theory that genetic distances had always increased with time
in the past history of life on Earth
Liu, A.G.,
Seiffert, E.R., Simons, E.L., 2008. Stable isotope evidence for an
amphibious phase in early proboscidean evolution. Proc. Natl. Acad. Sci.
U. S. A 105, 5786-5791.
Abstract: The order Proboscidea includes extant elephants and their
extinct relatives and is closely related to the aquatic sirenians
(manatees and dugongs) and terrestrial hyracoids (hyraxes). Some
analyses of embryological, morphological, and paleontological data
suggest that proboscideans and sirenians shared an aquatic or
semiaquatic common ancestor, but independent tests of this hypothesis
have proven elusive. Here we test the hypothesis of an aquatic ancestry
for advanced proboscideans by measuring delta(18)O in tooth enamel of
two late Eocene proboscidean genera, Barytherium and Moeritherium, which
are sister taxa of Oligocene-to-Recent proboscideans. The combination of
low delta(18)O values and low delta(18)O standard deviations in
Barytherium and Moeritherium matches the isotopic pattern seen in
aquatic and semiaquatic mammals, and differs from that of terrestrial
mammals. delta(13)C values of these early proboscideans suggest that
both genera are likely to have consumed freshwater plants, although a
component of C(3) terrestrial vegetation cannot be ruled out. The
simplest explanation for the combined evidence from isotopes, dental
functional morphology, and depositional environments is that Barytherium
and Moeritherium were at least semiaquatic and lived in freshwater swamp
or riverine environments, where they grazed on freshwater vegetation.
These results lend new support to the hypothesis that
Oligocene-to-Recent proboscideans are derived from amphibious ancestors
Lotfy, W.M.,
Brant, S.V., DeJong, R.J., Le, T.H., Demiaszkiewicz, A., Rajapakse, R.P.,
Perera, V.B., Laursen, J.R., Loker, E.S., 2008. Evolutionary origins,
diversification, and biogeography of liver flukes (Digenea, Fasciolidae).
American Journal of Tropical Medicine and Hygiene 79, 248-255.
Abstract: Fasciolid flukes are among the largest and best known
digenetic trematodes and have considerable historical and veterinary
significance. Fasciola hepatica is commonly implicated in causing
disease in humans. The origins, patterns of diversification, and
biogeography of fasciolids are all poorly known. We have undertaken a
molecular phylogenetic study using 28S, internal transcribed spacer 1
and 2 (ITS-1 and ITS-2) of nuclear ribosomal DNA, and mitochondrial
nicotinamide dehydrogenase subunit 1 (nad1) that included seven of the
nine recognized species in the family. The fasciolids examined comprise
a monophyletic group with the most basal species recovered from African
elephants. We hypothesize fasciolids migrated from Africa to Eurasia,
with secondary colonization of Africa. Fasciolids have been conservative
in maintaining relatively large adult body size, but anatomical features
of their digestive and reproductive systems are available. These flukes
have been opportunistic, with respect to switching to new snail (planorbid
to lymnaeid) and mammalian hosts and from intestinal to hepatic habitats
within mammals
Lynch, V.J.,
Tanzer, A., Wang, Y., Leung, F.C., Gellersen, B., Emera, D., Wagner, G.P.,
2008. Adaptive changes in the transcription factor HoxA-11 are essential
for the evolution of pregnancy in mammals. Proc. Natl. Acad. Sci. U. S.
A 105, 14928-14933.
Abstract: Evolutionary change in gene regulation can result from changes
in cis-regulatory elements, leading to differences in the temporal and
spatial expression of genes or in the coding region of transcription
factors leading to novel functions or both. Although there is a growing
body of evidence supporting the importance of cis-regulatory evolution,
examples of protein-mediated evolution of novel developmental pathways
have not been demonstrated. Here, we investigate the evolution of
prolactin (PRL) expression in endometrial cells, which is essential for
placentation/pregnancy in eutherian mammals and is a direct regulatory
target of the transcription factor HoxA-11. Here, we show that (i)
endometrial PRL expression is a derived feature of placental mammals,
(ii) the PRL regulatory gene HoxA-11 experienced a period of strong
positive selection in the stem-lineage of eutherian mammals, and (iii)
only HoxA-11 proteins from placental mammals, including the
reconstructed ancestral eutherian gene, are able to up-regulate PRL from
the promoter used in endometrial cells. In contrast, HoxA-11 from the
reconstructed therian ancestor, opossum, platypus, and chicken are
unable to up-regulate PRL expression. These results demonstrate that the
evolution of novel gene expression domains is not only mediated by the
evolution of cis-regulatory elements but can also require evolutionary
changes of transcription factor proteins themselves
Makarieva,
A.M., Gorshkov, V.G., Li, B.L., Chown, S.L., Reich, P.B., Gavrilov, V.M.,
2008. Mean mass-specific metabolic rates are strikingly similar across
life's major domains: Evidence for life's metabolic optimum. Proc. Natl.
Acad. Sci. U. S. A 105, 16994-16999.
Abstract: A fundamental but unanswered biological question asks how much
energy, on average, Earth's different life forms spend per unit mass per
unit time to remain alive. Here, using the largest database to date, for
3,006 species that includes most of the range of biological diversity on
the planet-from bacteria to elephants, and algae to sapling trees-we
show that metabolism displays a striking degree of homeostasis across
all of life. We demonstrate that, despite the enormous biochemical,
physiological, and ecological differences between the surveyed species
that vary over 10(20)-fold in body mass, mean metabolic rates of major
taxonomic groups displayed at physiological rest converge on a narrow
range from 0.3 to 9 W kg(-1). This 30-fold variation among life's
disparate forms represents a remarkably small range compared with the
4,000- to 65,000-fold difference between the mean metabolic rates of the
smallest and largest organisms that would be observed if life as a whole
conformed to universal quarter-power or third-power allometric scaling
laws. The observed broad convergence on a narrow range of basal
metabolic rates suggests that organismal designs that fit in this
physiological window have been favored by natural selection across all
of life's major kingdoms, and that this range might therefore be
considered as optimal for living matter as a whole
Meyers, D.A.,
Isaza, R., MacNeill, A.
Evaluation of acute phase proteins for diagnosis of inflammation in
Asian elephants ( Elephas maximus).
Proc American Associaton of Zoo Veterinarians and Assoc of Reptile and
Amphibian Veterinarians. 128. 2008. 11-10-2008.
Ref Type: Conference Proceeding
Abstract:
In many domestic species, routine hematology assays are useful
diagnostic tools to diagnose inflammatory conditions. Unlike other
species, these hematologic tests apparently are insensitive indicators
of inflammation in elephants.1 We studied a novel group of blood
proteins, called acute phase proteins, which increase during
inflammatory conditions, for their usefulness in diagnosing elephants
with inflammatory diseases. Although these proteins currently are useful
in humans and domestic animals, each species has a different set of
important proteins that must be individually investigated.2 We tested
several acute phase proteins (C-reactive protein, alpha-1 glycoprotein,
alpha-1 antitrypsin, serum amyloid A, haptoglobin, fibrinogen,
ceruloplasmin, and albumin) as well as complete blood counts, chemistry
panels, serum protein electrophoresis, and 3-D gel electrophoresis to
determine their usefulness for diagnosing different types of
inflammatory conditions in Asian elephants (Elephas maximus).
Animals with inflammatory conditions were classified as those
individuals with known illnesses such as mycobacteriosis, arthritis,
nail bed abscesses, and malignant tumors. Control animals were
thoseanimals that were suspected to not have any inflammation and be
healthy at the time of testing as determined by physical examination and
obtaining a thorough medical history.
LITERATURE CITED
1. Lyashchenko, K., R. Greenwald, J. Esfandiari, J. Olsen, R. Ball,
G. Dumonceaux, F. Dunker, C. Buckley, M.
Richard, S. Murray, J.B. Payeur, P. Anderson, J.M. Pollock, S. Mikota,
M. Miller, D. Sofranko, and W.R.
Waters. 2006. Tuberculosis in Elephants: Antibody responses to defined
antigens of Mycobacterium
tuberculosis, potential for early diagnosis, and monitoring of
treatment. Clin. Vacc. Immunol. 13: 722-732.
2. Murata H., N. Shimada, M. Yoshioka. 2004. Current research on acute
phase proteins in veterinary diagnosis:
an overview. Vet J. 168: 28-40.
Miller, W.,
Drautz, D.I., Ratan, A., Pusey, B., Qi, J., Lesk, A.M., Tomsho, L.P.,
Packard, M.D., Zhao, F., Sher, A., Tikhonov, A., Raney, B., Patterson,
N., Lindblad-Toh, K., Lander, E.S., Knight, J.R., Irzyk, G.P.,
Fredrikson, K.M., Harkins, T.T., Sheridan, S., Pringle, T., Schuster,
S.C., 2008. Sequencing the nuclear genome of the extinct woolly mammoth.
Nature 456, 387-390.
Abstract: In 1994, two independent groups extracted DNA from several
Pleistocene epoch mammoths and noted differences among individual
specimens. Subsequently, DNA sequences have been published for a number
of extinct species. However, such ancient DNA is often fragmented and
damaged, and studies to date have typically focused on short
mitochondrial sequences, never yielding more than a fraction of a per
cent of any nuclear genome. Here we describe 4.17 billion bases (Gb) of
sequence from several mammoth specimens, 3.3 billion (80%) of which are
from the woolly mammoth (Mammuthus primigenius) genome and thus comprise
an extensive set of genome-wide sequence from an extinct species. Our
data support earlier reports that elephantid genomes exceed 4 Gb. The
estimated divergence rate between mammoth and African elephant is half
of that between human and chimpanzee. The observed number of nucleotide
differences between two particular mammoths was approximately one-eighth
of that between one of them and the African elephant, corresponding to a
separation between the mammoths of 1.5-2.0 Myr. The estimated
probability that orthologous elephant and mammoth amino acids differ is
0.002, corresponding to about one residue per protein. Differences were
discovered between mammoth and African elephant in amino-acid positions
that are otherwise invariant over several billion years of combined
mammalian evolution. This study shows that nuclear genome sequencing of
extinct species can reveal population differences not evident from the
fossil record, and perhaps even discover genetic factors that affect
extinction
Nathan, R.,
Getz, W.M., Revilla, E., Holyoak, M., Kadmon, R., Saltz, D., Smouse,
P.E., 2008. A movement ecology paradigm for unifying organismal movement
research. Proc. Natl. Acad. Sci. U. S. A 105, 19052-19059.
Abstract: Movement of individual organisms is fundamental to life,
quilting our planet in a rich tapestry of phenomena with diverse
implications for ecosystems and humans. Movement research is both
plentiful and insightful, and recent methodological advances facilitate
obtaining a detailed view of individual movement. Yet, we lack a general
unifying paradigm, derived from first principles, which can place
movement studies within a common context and advance the development of
a mature scientific discipline. This introductory article to the
Movement Ecology Special Feature proposes a paradigm that integrates
conceptual, theoretical, methodological, and empirical frameworks for
studying movement of all organisms, from microbes to trees to elephants.
We introduce a conceptual framework depicting the interplay among four
basic mechanistic components of organismal movement: the internal state
(why move?), motion (how to move?), and navigation (when and where to
move?) capacities of the individual and the external factors affecting
movement. We demonstrate how the proposed framework aids the study of
various taxa and movement types; promotes the formulation of hypotheses
about movement; and complements existing biomechanical, cognitive,
random, and optimality paradigms of movement. The proposed framework
integrates eclectic research on movement into a structured paradigm and
aims at providing a basis for hypothesis generation and a vehicle
facilitating the understanding of the causes, mechanisms, and
spatiotemporal patterns of movement and their role in various ecological
and evolutionary processes. "Now we must consider in general the common
reason for moving with any movement whatever." (Aristotle, De Motu
Animalium, 4th century B.C.)
Nicholls, H.,
2008. Darwin 200: Let's make a mammoth. Nature 456, 310-314.
Nishihara,
H., Okada, N., 2008. Retroposons: genetic footprints on the evolutionary
paths of life. Methods Mol. Biol. 422, 201-225.
Abstract: Retroposons such as short interspersed elements (SINEs) and
long interspersed elements are abundant transposable elements in
eukaryote genomes. Recent large-scale comparative genome analyses have
revealed that retroposons are a major component of genomes, wherein they
provide structural diversity between species and uniqueness to each
species. SINEs have been used as powerful markers in phylogenetic
analyses of various species. This approach, which has been termed the
SINE insertion method, infers phylogenetic relationships based on the
presence/absence of SINEs among lineages. However, the method is not yet
used extensively among biologists, especially molecular phylogenetists,
because it is based on an understanding of the molecular mechanisms of
retroposition, which may be unfamiliar to many researchers. Moreover,
the method may require a large amount of bench work to characterize a
new SINE family and to screen genomic libraries of the species of
interest. In this chapter, we present the basic theory and detailed
technical steps involved in a SINE insertion analysis. Furthermore, we
explain the isolation and characterization of a new SINE family from the
genome of a species of interest using as an example a known SINE family
in mammals
Nogues-Bravo,
D., Rodriguez, J., Hortal, J., Batra, P., Araujo, M.B., 2008. Climate
change, humans, and the extinction of the woolly mammoth. PLoS. Biol. 6,
e79.
Abstract: Woolly mammoths inhabited Eurasia and North America from late
Middle Pleistocene (300 ky BP [300,000 years before present]), surviving
through different climatic cycles until they vanished in the Holocene
(3.6 ky BP). The debate about why the Late Quaternary extinctions
occurred has centred upon environmental and human-induced effects, or a
combination of both. However, testing these two hypotheses-climatic and
anthropogenic-has been hampered by the difficulty of generating
quantitative estimates of the relationship between the contraction of
the mammoth's geographical range and each of the two hypotheses. We
combined climate envelope models and a population model with explicit
treatment of woolly mammoth-human interactions to measure the extent to
which a combination of climate changes and increased human pressures
might have led to the extinction of the species in Eurasia. Climate
conditions for woolly mammoths were measured across different time
periods: 126 ky BP, 42 ky BP, 30 ky BP, 21 ky BP, and 6 ky BP. We show
that suitable climate conditions for the mammoth reduced drastically
between the Late Pleistocene and the Holocene, and 90% of its
geographical range disappeared between 42 ky BP and 6 ky BP, with the
remaining suitable areas in the mid-Holocene being mainly restricted to
Arctic Siberia, which is where the latest records of woolly mammoths in
continental Asia have been found. Results of the population models also
show that the collapse of the climatic niche of the mammoth caused a
significant drop in their population size, making woolly mammoths more
vulnerable to the increasing hunting pressure from human populations.
The coincidence of the disappearance of climatically suitable areas for
woolly mammoths and the increase in anthropogenic impacts in the
Holocene, the coup de grace, likely set the place and time for the
extinction of the woolly mammoth
Okello, J.B.,
Wittemyer, G., Rasmussen, H.B., Arctander, P., Nyakaana, S.,
Douglas-Hamilton, I., Siegismund, H.R., 2008. Effective population size
dynamics reveal impacts of historic climatic events and recent
anthropogenic pressure in African elephants. Mol. Ecol. 17,
3788-3799.
Abstract: Two hundred years of elephant hunting for ivory, peaking in
1970-1980s, caused local extirpations and massive population declines
across Africa. The resulting genetic impacts on surviving populations
have not been studied, despite the importance of understanding the
evolutionary repercussions of such human-mediated events on this
keystone species. Using Bayesian coalescent-based genetic methods to
evaluate time-specific changes in effective population size, we analysed
genetic variation in 20 highly polymorphic microsatellite loci from 400
elephants inhabiting the greater Samburu-Laikipia region of northern
Kenya. This area experienced a decline of between 80% and 90% in the
last few decades when ivory harvesting was rampant. The most significant
change in effective population size, however, occurred approximately
2500 years ago during a mid-Holocene period of climatic drying in
tropical Africa. Contrary to expectations, detailed analyses of four
contemporary age-based cohorts showed that the peak poaching epidemic in
the 1970s caused detectable temporary genetic impacts, with genetic
diversity rebounding as juveniles surviving the poaching era became
reproductively mature. This study demonstrates the importance of
climatic history in shaping the distribution and genetic history of a
keystone species and highlights the utility of coalescent-based
demographic approaches in unravelling ancestral demographic events
despite a lack of ancient samples. Unique insights into the genetic
signature of mid-Holocene climatic change in Africa and effects of
recent poaching pressure on elephants are discussed
Organ, C.L.,
Schweitzer, M.H., Zheng, W., Freimark, L.M., Cantley, L.C., Asara, J.M.,
2008. Molecular phylogenetics of mastodon and Tyrannosaurus rex. Science
320, 499.
Abstract: We report a molecular phylogeny for a nonavian dinosaur,
extending our knowledge of trait evolution within nonavian dinosaurs
into the macromolecular level of biological organization. Fragments of
collagen alpha1(I) and alpha2(I) proteins extracted from fossil bones of
Tyrannosaurus rex and Mammut americanum (mastodon) were analyzed with a
variety of phylogenetic methods. Despite missing sequence data, the
mastodon groups with elephant and the T. rex groups with birds,
consistent with predictions based on genetic and morphological data for
mastodon and on morphological data for T. rex. Our findings suggest that
molecular data from long-extinct organisms may have the potential for
resolving relationships at critical areas in the vertebrate evolutionary
tree that have, so far, been phylogenetically intractable
Perelygin,
A.A., Zharkikh, A.A., Astakhova, N.M., Lear, T.L., Brinton, M.A., 2008.
Concerted evolution of vertebrate CCR2 and CCR5 genes and the origin of
a recombinant equine CCR5/2 gene. J. Hered. 99, 500-511.
Abstract: Chemokine receptors (CCRs) play an essential role in the
initiation of an innate immune host response. Several of these receptors
have been shown to modulate the outcome of viral infections. The recent
availability of complete genome sequences from a number of species
provides a unique opportunity to analyze the evolution of the CCR genes.
A phylogenetic analysis revealed that the CCR2 gene evolved in concert
with the paralogous CCR5 gene, but not with another paralogous gene,
CCR3, in the opossum, platypus, rabbit, guinea pig, cat, and rodent
lineages. In addition, evidence of concerted evolution of the CCR2 and
CCR5 genes was observed in chicken and lizard genomes. A unique CCR5/2
gene that originated by unequal crossing over between the CCR2 and CCR5
genes was detected in the domestic horse. The CCR2, CCR5, and CCR5/2
genes were mapped to ECA16q21 using fluorescent in situ hybridization
(FISH). Single-nucleotide polymorphisms identified in the equine CCR5
gene and characterized within 5 horse breeds provide haplotype markers
for future case/control studies investigating the genetic bases of horse
susceptibility to infectious diseases
Tyack, P.L.,
2008. Convergence of calls as animals form social bonds, active
compensation for noisy communication channels, and the evolution of
vocal learning in mammals. J. Comp Psychol. 122, 319-331.
Abstract: The classic evidence for vocal production learning involves
imitation of novel, often anthropogenic sounds. Among mammals, this has
been reported for dolphins, elephants, harbor seals, and humans. A
broader taxonomic distribution has been reported for vocal convergence,
where the acoustic properties of calls from different individuals
converge when they are housed together in captivity or form social bonds
in the wild. Vocal convergence has been demonstrated for animals as
diverse as songbirds, parakeets, hummingbirds, bats, elephants,
cetaceans, and primates. For most species, call convergence is thought
to reflect a group-distinctive identifier, with shared calls reflecting
and strengthening social bonds. A ubiquitous function for vocal
production learning that is starting to receive attention involves
modifying signals to improve communication in a noisy channel. Pooling
data on vocal imitation, vocal convergence, and compensation for noise
suggests a wider taxonomic distribution of vocal production learning
among mammals than has been generally appreciated. The wide taxonomic
distribution of this evidence for vocal production learning suggests
that perhaps more of the neural underpinnings for vocal production
learning are in place in mammals than is usually recognized
Wallis, M.,
2008. Mammalian genome projects reveal new growth hormone (GH)
sequences. Characterization of the GH-encoding genes of armadillo (Dasypus
novemcinctus), hedgehog (Erinaceus europaeus), bat (Myotis lucifugus),
hyrax (Procavia capensis), shrew (Sorex araneus), ground squirrel (Spermophilus
tridecemlineatus), elephant (Loxodonta africana), cat (Felis catus) and
opossum (Monodelphis domestica). Gen. Comp Endocrinol. 155,
271-279.
Abstract: Mammalian growth hormone (GH) sequences have been shown
previously to display episodic evolution: the sequence is generally
strongly conserved but on at least two occasions during mammalian
evolution (on lineages leading to higher primates and ruminants) bursts
of rapid evolution occurred. However, the number of mammalian orders
studied previously has been relatively limited, and the availability of
sequence data via mammalian genome projects provides the potential for
extending the range of GH gene sequences examined. Complete or nearly
complete GH gene sequences for six mammalian species for which no data
were previously available have been extracted from the genome databases-Dasypus
novemcinctus (nine-banded armadillo), Erinaceus europaeus (western
European hedgehog), Myotis lucifugus (little brown bat), Procavia
capensis (cape rock hyrax), Sorex araneus (European shrew), Spermophilus
tridecemlineatus (13-lined ground squirrel). In addition incomplete data
for several other species have been extended. Examination of the data in
detail and comparison with previously available sequences has allowed
assessment of the reliability of deduced sequences. Several of the new
sequences differ substantially from the consensus sequence previously
determined for eutherian GHs, indicating greater variability than
previously recognised, and confirming the episodic pattern of evolution.
The episodic pattern is not seen for signal sequences, 5' upstream
sequence or synonymous substitutions-it is specific to the mature
protein sequence, suggesting that it relates to the hormonal function.
The substitutions accumulated during the course of GH evolution have
occurred mainly on the side of the hormone facing away from the
receptor, in a non-random fashion, and it is suggested that this may
reflect interaction of the receptor-bound hormone with other proteins or
small ligands
Archie, E.A.,
Hollister-Smith, J.A., Poole, J.H., Lee, P.C., Moss, C.J., Maldonado,
J.E., Fleischer, R.C., Alberts, S.C., 2007. Behavioural inbreeding
avoidance in wild African elephants. Molecular Ecology 16,
4138-4148.
Abstract: The costs of inbreeding depression, as well as the opportunity
costs of inbreeding avoidance, determine whether and which mechanisms of
inbreeding avoidance evolve. In African elephants, sex-biased dispersal
does not lead to the complete separation of male and female relatives,
and so individuals may experience selection to recognize kin and avoid
inbreeding. However, because estrous females are rare and male-male
competition for mates is intense, the opportunity costs of inbreeding
avoidance may be high, particularly for males. Here we combine 28 years
of behavioural and demographic data on wild elephants with genotypes
from 545 adult females, adult males, and calves in Amboseli National
Park, Kenya, to test the hypothesis that elephants engage in sexual
behaviour and reproduction with relatives less often than expected by
chance. We found support for this hypothesis: males engaged in
proportionally fewer sexual behaviours and sired proportionally fewer
offspring with females that were natal family members or close genetic
relatives (both maternal and paternal) than they did with nonkin. We
discuss the relevance of these results for understanding the evolution
of inbreeding avoidance and for elephant conservation.
Aroch, I.,
King, R., Baneth, G., 2007. Hematology and serum biochemistry values of
trapped, healthy, free-ranging rock hyraxes (Procavia capensis) and
their association with age, sex, and gestational status. Vet. Clin.
Pathol. 36, 40-48.
Abstract: BACKGROUND: The rock hyrax (Procavia capensis) is an herbivore
prevalent from South Africa to Turkey, and a most common zoo animal.
Although many studies of hyrax diseases and physiology are available,
clinicopathologic data are limited. OBJECTIVES: The purpose of this
study was to establish comprehensive hematologic and biochemical
reference intervals for trapped, apparently healthy, free-ranging rock
hyraxes using modern laboratory methods and to assess differences
related to sex, gestation, and age. METHODS: Blood samples were obtained
from 27 healthy, free-ranging hyraxes under anesthesia. Gender, body
weight, and gestational status were recorded. Hematologic (n = 25) and
serum biochemical (n = 22) analyses were performed using standard
automated methodology. Data for male vs female, adult vs juvenile, and
pregnant vs nonpregnant female hyraxes were compared using the
Mann-Whitney U-test. Associations between variables were assessed using
Pearson's or Spearman rank correlation tests. RESULTS: Significant age-
and sex-related, but not gestation-related differences were observed in
several variables. Serum alkaline phosphatase activity and phosphorus
concentration were significantly higher in juveniles compared with
adults. A unique type of monocyte comprised 1-3% of leukocytes in 4
hyraxes. Markedly high serum creatine kinase (CK) activity was observed
in most hyraxes. CONCLUSIONS: The large number of animals and the
availability of sex, age, and gestational data in this study will be
useful to zoo and wildlife veterinarians working with rock hyraxes. High
serum concentrations of betahydroxybutyric acid in the rock hyrax,
compared with dogs, cats, and ruminants, may be related to its unique
digestive system. High CK activity may have been the result of a capture
myopathy-like syndrome. The unique monocytes in hyraxes resemble those
of elephants and are a novel finding in this species
Asara, J.M.,
Schweitzer, M.H., Freimark, L.M., Phillips, M., Cantley, L.C., 2007.
Protein sequences from mastodon and Tyrannosaurus rex revealed by mass
spectrometry. Science 316, 280-285.
Abstract: Fossilized bones from extinct taxa harbor the potential for
obtaining protein or DNA sequences that could reveal evolutionary links
to extant species. We used mass spectrometry to obtain protein sequences
from bones of a 160,000- to 600,000-year-old extinct mastodon (Mammut
americanum) and a 68-million-year-old dinosaur (Tyrannosaurus rex). The
presence of T. rex sequences indicates that their peptide bonds were
remarkably stable. Mass spectrometry can thus be used to determine
unique sequences from ancient organisms from peptide fragmentation
patterns, a valuable tool to study the evolution and adaptation of
ancient taxa from which genomic sequences are unlikely to be obtained.
Division of Signal Transduction, Beth Israel Deaconess Medical Center,
Boston, MA 02115, USA. jasara@bidmc.harvard.edu
Barnes, I.,
Shapiro, B., Lister, A., Kuznetsova, T., Sher, A., Guthrie, D., Thomas,
M.G., 2007. Genetic structure and extinction of the woolly mammoth,
Mammuthus primigenius. Curr. Biol. 17, 1072-1075.
Abstract: The interval since circa 50 Ka has been a period of
significant species extinctions among the large mammal fauna. However,
the relative roles of an increasing human presence and a synchronous
series of complex environmental changes in these extinctions have yet to
be fully resolved. Recent analyses of fossil material from Beringia have
clarified our understanding of the spatiotemporal pattern of Late
Pleistocene extinctions, identifying periods of population turnover well
before the last glacial maximum (LGM: circa 21 Ka) or subsequent human
expansion. To examine the role of pre-LGM population changes in shaping
the genetic structure of an extinct species, we analyzed the
mitochondrial DNA of woolly mammoths in western Beringia and across its
range. We identify genetic signatures of a range expansion of mammoths,
from eastern to western Beringia, after the last interglacial (circa 125
Ka), and then an extended period during which demographic inference
indicates no population-size increase. The most marked change in
diversity at this time is the loss of one of two major mitochondrial
lineages
Bates, L.A.,
Byrne, R.W., 2007. Creative or created: using anecdotes to investigate
animal cognition. Methods 42, 12-21.
Abstract: In non-human animals, creative behaviour occurs spontaneously
only at low frequencies, so is typically missed by standardised
observational methods. Experimental approaches have tended to rely
overly on paradigms from child development or adult human cognition,
which may be inappropriate for species that inhabit very different
perceptual worlds and possess quite different motor capacities than
humans. The analysis of anecdotes offers a solution to this impasse,
provided certain conditions are met. To be reliable, anecdotes must be
recorded immediately after observation, and only the records of
scientists experienced with the species and the individuals concerned
should be used. Even then, interpretation of a single record is always
ambiguous, and analysis is feasible only when collation of multiple
records shows that a behaviour pattern occurs repeatedly under similar
circumstances. This approach has been used successfully to study a
number of creative capacities of animals: the distribution, nature and
neural correlates of deception across the primate order; the occurrence
of teaching in animals; and the neural correlates of several
aptitudes--in birds, foraging innovation, and in primates, innovation,
social learning and tool-use. Drawing on these approaches, we describe
the use of this method to investigate a new problem, the cognition of
the African elephant, a species whose sheer size and evolutionary
distance from humans renders the conventional methods of comparative
psychology of little use. The aim is both to chart the creative
cognitive capacities of this species, and to devise appropriate
experimental methods to confirm and extend previous findings
Binladen, J.,
Gilbert, M.T., Willerslev, E., 2007. 800,000 year old mammoth DNA,
modern elephant DNA or PCR artefact? Biol. Lett. 3, 55-56.
Abstract: Poulakakis and colleagues (Poulakakis et al. 2006: Biol. Lett.
2, 451-454), report the recovery of 'authentic' mammoth DNA from an
800,000-year-old fragment of bone excavated on the island of Crete. In
light of results from other ancient DNA studies that indicate how DNA
survival is unlikely in samples, which are recovered from warm
environments and are relatively old (e.g. more than 100,000 years),
these findings come as a great surprise. Here, we show that problems
exist with the methodological approaches used in the study. First, the
nested PCR technique as reported is nonsensical--one of the second round
'nested' primers falls outside the amplicon of the first round PCR. More
worryingly, the binding region of one of the first round primers
(Elcytb320R) falls within the short 43 base pair reported mammoth
sequence, specifically covering two of the three reportedly diagnostic
Elephas polymorphisms. Finally, we demonstrate using a simple BLAST
search in GenBank that the claimed 'uniquely derived character state'
for mammoths is in fact also found within modern elephants
Fritsch, A.,
Hellmich, C., 2007. 'Universal' microstructural patterns in cortical and
trabecular, extracellular and extravascular bone materials:
micromechanics-based prediction of anisotropic elasticity
390. Journal of Theoretical Biology 244, 597-620.
Abstract: Bone materials are characterized by an astonishing variability
and diversity. Still, because of 'architectural constraints' due to once
chosen material constituents and their physical interaction, the
fundamental hierarchical organization or basic building plans of bone
materials remain largely unchanged during biological evolution. Such
universal patterns of microstructural organization govern the mechanical
interaction of the elementary components of bone (hydroxyapatite,
collagen, water; with directly measurable tissue-independent elastic
properties), which are here quantified through a multiscale
homogenization scheme delivering effective elastic properties of bone
materials: at a scale of 10nm, long cylindrical collagen molecules,
attached to each other at their ends by approximately 1.5nm long
crosslinks and hosting intermolecular water inbetween, form a contiguous
matrix called wet collagen. At a scale of several hundred nanometers,
wet collagen and mineral crystal agglomerations interpenetrate each
other, forming the mineralized fibril. At a scale of 5-10microm, the
extracellular solid bone matrix is represented as collagen fibril
inclusions embedded in a foam of largely disordered (extrafibrillar)
mineral crystals. At a scale above the ultrastructure, where lacunae are
embedded in extracellular bone matrix, the extravascular bone material
is observed. Model estimates predicted from tissue-specific composition
data gained from a multitude of chemical and physical tests agree
remarkably well with corresponding acoustic stiffness experiments across
a variety of cortical and trabecular, extracellular and extravascular
materials. Besides from reconciling the well-documented, seemingly
opposed concepts of 'mineral-reinforced collagen matrix' and
'collagen-reinforced mineral matrix' for bone ultrastructure, this
approach opens new possibilities in the exploitation of computer
tomographic data for nano-to-macro mechanics of bone organs
Gilbert, M.T.,
Binladen, J., Miller, W., Wiuf, C., Willerslev, E., Poinar, H., Carlson,
J.E., Leebens-Mack, J.H., Schuster, S.C., 2007. Recharacterization of
ancient DNA miscoding lesions: insights in the era of
sequencing-by-synthesis
422. Nucleic Acids Res. 35, 1-10.
Abstract: Although ancient DNA (aDNA) miscoding lesions have been
studied since the earliest days of the field, their nature remains a
source of debate. A variety of conflicting hypotheses exist about which
miscoding lesions constitute true aDNA damage as opposed to PCR
polymerase amplification error. Furthermore, considerable disagreement
and speculation exists on which specific damage events underlie observed
miscoding lesions. The root of the problem is that it has previously
been difficult to assemble sufficient data to test the hypotheses, and
near-impossible to accurately determine the specific strand of origin of
observed damage events. With the advent of emulsion-based clonal
amplification (emPCR) and the sequencing-by-synthesis technology this
has changed. In this paper we demonstrate how data produced on the Roche
GS20 genome sequencer can determine miscoding lesion strands of origin,
and subsequently be interpreted to enable characterization of the aDNA
damage behind the observed phenotypes. Through comparative analyses on
390,965 bp of modern chloroplast and 131,474 bp of ancient woolly
mammoth GS20 sequence data we conclusively demonstrate that in this
sample at least, a permafrost preserved specimen, Type 2
(cytosine-->thymine/guanine-->adenine) miscoding lesions represent the
overwhelming majority of damage-derived miscoding lesions. Additionally,
we show that an as yet unidentified guanine-->adenine analogue
modification, not the conventionally argued cytosine-->uracil
deamination, underpins a significant proportion of Type 2 damage. How
widespread these implications are for aDNA will become apparent as
future studies analyse data recovered from a wider range of substrates
Kellogg,
M.E., Burkett, S., Dennis, T.R., Stone, G., Gray, B.A., McGuire, P.M.,
Zori, R.T., Stanyon, R., 2007. Chromosome painting in the manatee
supports Afrotheria and Paenungulata. BMC. Evol. Biol. 7, 6.
Abstract: BACKGROUND: Sirenia (manatees, dugongs and Stellar's sea cow)
have no evolutionary relationship with other marine mammals, despite
similarities in adaptations and body shape. Recent phylogenomic results
place Sirenia in Afrotheria and with elephants and rock hyraxes in
Paenungulata. Sirenia and Hyracoidea are the two afrotherian orders as
yet unstudied by comparative molecular cytogenetics. Here we report on
the chromosome painting of the Florida manatee. RESULTS: The human
autosomal and X chromosome paints delimited a total of 44 homologous
segments in the manatee genome. The synteny of nine of the 22 human
autosomal chromosomes (4, 5, 6, 9, 11, 14, 17, 18 and 20) and the X
chromosome were found intact in the manatee. The syntenies of other
human chromosomes were disrupted in the manatee genome into two to five
segments. The hybridization pattern revealed that 20 (15 unique)
associations of human chromosome segments are found in the manatee
genome: 1/15, 1/19, 2/3 (twice), 3/7 (twice), 3/13, 3/21, 5/21, 7/16,
8/22, 10/12 (twice), 11/20, 12/22 (three times), 14/15, 16/19 and 18/19.
CONCLUSION: There are five derived chromosome traits that strongly link
elephants with manatees in Tethytheria and give implicit support to
Paenungulata: the associations 2/3, 3/13, 8/22, 18/19 and the loss of
the ancestral eutherian 4/8 association. It would be useful to test
these conclusions with chromosome painting in hyraxes. The manatee
chromosome painting data confirm that the associations 1/19 and 5/21
phylogenetically link afrotherian species and show that Afrotheria is a
natural clade. The association 10/12/22 is also ubiquitous in Afrotheria
(clade I), present in Laurasiatheria (clade IV), only partially present
in Xenarthra (10/12, clade II) and absent in Euarchontoglires (clade
III). If Afrotheria is basal to eutherians, this association could be
part of the ancestral eutherian karyotype. If afrotherians are not at
the root of the eutherian tree, then the 10/12/22 association could be
one of a suite of derived associations linking afrotherian taxa
Kerr, R.A.,
2007. Paleontology. Mammoth-killer impact gets mixed reception from
Earth scientists. Science 316, 1264-1265.
Kullberg, M.,
Hallström, B., Arnason, U., Janke, A., 2007. Expressed sequence tags as
a tool for phylogenetic analysis of placental mammal evolution. PLoS ONE
E publication Aug 22;2(1):e775.
Abstract: BACKGROUND: We investigate the usefulness of expressed
sequence tags, ESTs, for establishing divergences within the tree of
placental mammals. This is done on the example of the established
relationships among primates (human), lagomorphs (rabbit), rodents (rat
and mouse), artiodactyls (cow), carnivorans (dog) and proboscideans
(elephant). METHODOLOGY/PRINCIPAL FINDINGS: We have produced 2000 ESTs
(1.2 mega bases) from a marsupial mouse and characterized the data for
their use in phylogenetic analysis. The sequences were used to identify
putative orthologous sequences from whole genome projects. Although most
ESTs stem from single sequence reads, the frequency of potential
sequencing errors was found to be lower than allelic variation. Most of
the sequences represented slowly evolving housekeeping-type genes, with
an average amino acid distance of 6.6% between human and mouse. Positive
Darwinian selection was identified at only a few single sites.
Phylogenetic analyses of the EST data yielded trees that were consistent
with those established from whole genome projects. CONCLUSIONS: The
general quality of EST sequences and the general absence of positive
selection in these sequences make ESTs an attractive tool for
phylogenetic analysis. The EST approach allows, at reasonable costs, a
fast extension of data sampling from species outside the genome
projects.
Murphy, W.J.,
Pringle, T.H., Crider, T.A., Springer, M.S., Miller, W., 2007. Using
genomic data to unravel the root of the placental mammal phylogeny.
Genome Res. 17, 413-421.
Abstract: The phylogeny of placental mammals is a critical framework for
choosing future genome sequencing targets and for resolving the
ancestral mammalian genome at the nucleotide level. Despite considerable
recent progress defining superordinal relationships, several branches
remain poorly resolved, including the root of the placental tree. Here
we analyzed the genome sequence assemblies of human, armadillo,
elephant, and opossum to identify informative coding indels that would
serve as rare genomic changes to infer early events in placental mammal
phylogeny. We also expanded our species sampling by including sequence
data from >30 ongoing genome projects, followed by PCR and sequencing
validation of each indel in additional taxa. Our data provide support
for a sister-group relationship between Afrotheria and Xenarthra (the
Atlantogenata hypothesis), which is in turn the sister-taxon to
Boreoeutheria. We failed to recover any indels in support of a basal
position for Xenarthra (Epitheria), which is suggested by morphology and
a recent retroposon analysis, or a hypothesis with Afrotheria basal (Exafricoplacentalia),
which is favored by phylogenetic analysis of large nuclear gene data
sets. In addition, we identified two retroposon insertions that also
support Atlantogenata and none for the alternative hypotheses. A revised
molecular timescale based on these phylogenetic inferences suggests
Afrotheria and Xenarthra diverged from other placental mammals
approximately 103 (95-114) million years ago. We discuss the impacts of
this topology on earlier phylogenetic reconstructions and repeat-based
inferences of phylogeny
Orlando, L.,
Pages, M., Calvignac, S., Hughes, S., Hanni, C., 2007. Does the 43 bp
sequence from an 800,000 year old Cretan dwarf elephantid really rewrite
the textbook on mammoths? Biology Letters 3, 57-59.
Abstract: Pigmy elephants inhabited the islands from the Mediterranean
region during the Pleistocene period but became extinct in the course of
the Holocene. Despite striking distinctive anatomical characteristics
related to insularity, some similarities with the lineage of extant
Asian elephants have suggested that pigmy elephants could be most
probably seen as members of the genus Elephas. Poulakakis et al. (2006)
have recently challenged this view by recovering a short mtDNA sequence
from an 800 000 year old fossil of the Cretan pigmy elephant (Elephas
creticus). According to the authors of this study, a deep taxonomic
revision of Cretan dwarf elephants would be needed, as the sequence
exhibits clear affinities with woolly mammoth haplotypes. However, we
point here many aspects that seriously weaken the strength of the
ancient DNA evidence reported.
Orlando, L.,
Pages, M., Calvignac, S., Hughes, S., Hanni, C., 2007. Does the 43 bp
sequence from an 800,000 year old cretan dwarf elephantid really rewrite
the textbook on mammoths? Biol. Lett. 3, 57-59.
Abstract: Pigmy elephants inhabited the islands from the Mediterranean
region during the Pleistocene period but became extinct in the course of
the Holocene. Despite striking distinctive anatomical characteristics
related to insularity, some similarities with the lineage of extant
Asian elephants have suggested that pigmy elephants could be most
probably seen as members of the genus Elephas. Poulakakis et al (2006)
have recently challenged this view by recovering a short mtDNA sequence
from an 800 000 year old fossil of the Cretan pigmy elephant (Elephas
creticus). According to the authors of this study, a deep taxonomic
revision of Cretan dwarf elephants would be needed, as the sequence
exhibits clear affinities with woolly mammoth haplotypes. However, we
point here many aspects that seriously weaken the strength of the
ancient DNA evidence reported
Orlando, L.,
Hanni, C., Douady, C.J., 2007. Mammoth and Elephant Phylogenetic
Relationships: Mammut Americanum, the Missing Outgroup. Evol. Bioinform.
Online. 3, 45-51.
Abstract: At the morphological level, the woolly mammoth has most often
been considered as the sister-species of Asian elephants, but at the DNA
level, different studies have found support for proximity with African
elephants. Recent reports have increased the available sequence data and
apparently solved the discrepancy, finding mammoths to be most closely
related to Asian elephants. However, we demonstrate here that the three
competing topologies have similar likelihood, bayesian and parsimony
supports. The analysis further suggests the inadequacy of using Sirenia
or Hyracoidea as outgroups. We therefore argue that orthologous
sequences from the extinct American mastodon will be required to
definitively solve this long-standing question
Pan, D.,
2007. Hippo signaling in organ size control. Genes Dev. 21,
886-897.
Abstract: The control of organ (or organism) size is a fundamental
aspect of life that has long captured human imagination. What makes an
elephant grow a million times larger than a mouse? How do our two hands
develop independently of each other yet reach very similar size? How
does a liver precisely regenerate its original mass when two-thirds of
it is removed? The recent discovery of a novel signaling network in
Drosophila, known as the Hippo (Hpo) pathway, might provide an important
entry point to these fascinating questions. The Hpo pathway consists of
several negative growth regulators acting in a kinase cascade that
ultimately phosphorylates and inactivates Yorkie (Yki), a
transcriptional coactivator that positively regulates cell growth,
survival, and proliferation. Components of the Hpo pathway are highly
conserved throughout evolution, suggesting that this pathway may
function as a global regulator of tissue homeostasis in all metazoan
animals. Here, I provide a historical review of this potent
growth-regulatory pathway and highlight outstanding questions that will
likely be the focus of future investigation
Pardini, A.T.,
O'Brien, P.C., Fu, B., Bonde, R.K., Elder, F.F., Ferguson-Smith, M.A.,
Yang, F., Robinson, T.J., 2007. Chromosome painting among Proboscidea,
Hyracoidea and Sirenia: support for Paenungulata (Afrotheria, Mammalia)
but not Tethytheria. Proc. Biol. Sci. 274, 1333-1340.
Abstract: Despite marked improvements in the interpretation of
systematic relationships within Eutheria, particular nodes, including
Paenungulata (Hyracoidea, Sirenia and Proboscidea), remain ambiguous.
The combination of a rapid radiation, a deep divergence and an extensive
morphological diversification has resulted in a limited phylogenetic
signal confounding resolution within this clade both at the
morphological and nucleotide levels. Cross-species chromosome painting
was used to delineate regions of homology between Loxodonta africana
(2n=56), Procavia capensis (2n=54), Trichechus manatus latirostris
(2n=48) and an outgroup taxon, the aardvark (Orycteropus afer, 2n=20).
Changes specific to each lineage were identified and although the
presence of a minimum of 11 synapomorphies confirmed the monophyly of
Paenungulata, no change characterizing intrapaenungulate relationships
was evident. The reconstruction of an ancestral paenungulate karyotype
and the estimation of rates of chromosomal evolution indicate a reduced
rate of genomic repatterning following the paenungulate radiation. In
comparison to data available for other mammalian taxa, the paenungulate
rate of chromosomal evolution is slow to moderate. As a consequence, the
absence of a chromosomal character uniting two paenungulates (at the
level of resolution characterized in this study) may be due to a reduced
rate of chromosomal change relative to the length of time separating
successive divergence events
Redi, C.A.,
Garagna, S., Zuccotti, M., Capanna, E., 2007. Genome size: a novel
genomic signature in support of Afrotheria. Journal of Molecular
Evolution 64, 484-487.
Abstract: Molecular phylogenetic analyses suggest an emerging phylogeny
for the extant Placentalia (eutherian) that radically departs from
morphologically based constructions of the past. Placental mammals are
partitioned into four supraordinal clades: Afrotheria, Xenarthra,
Laurasiatheria, and Euarchontoglires. Afrotheria form an endemic African
clade that includes elephant shrews, golden moles, tenrecs, aardvarks,
hyraxes, elephants, dugongs, and manatees. Datamining databases of
genome size (GS) shows that till today just one afrotherian GS has been
evaluated, that of the aardvark Orycteropus afer. We show that the GSs
of six selected representatives across the Afrotheria supraordinal group
are among the highest for the extant Placentalia, providing a novel
genomic signature of this enigmatic group. The mean GS value of
Afrotheria, 5.3 +/- 0.7 pg, is the highest reported for the extant
Placentalia. This should assist in planning new genome sequencing
initiatives
Roca, A.L.,
Georgiadis, N., O'Brien, S.J., 2007. Cyto-nuclear genomic dissociation
and the African elephant species question. Quat. Int. 169-170,
4-16.
Abstract: Studies of skull morphology and of nuclear DNA have strongly
concluded that African elephants comprise two species. Nonetheless,
Debruyne (2005) has suggested a single-species model for Loxodonta based
on the polyphyly of a single genetic locus, mitochondrial DNA (mtDNA).
Discordant patterns between mitochondrial and nuclear DNA markers were
subsequently reported in some African savanna elephant populations,
further supporting a two-species model, and prompting us to re-examine
here the geographic distribution of different elephant morphotypes and
their relationship to nuclear and mtDNA phylogeographic patterns. We
used exact tests to compare the distribution of forest elephant-typical
and savanna elephant-typical characteristics across eight published
datasets containing morphological, mtDNA or nuclear DNA data for African
elephants. Among the elephants examined by Debruyne (2005), we found
that patterns of forest vs. savanna characteristics were significantly
different (p < 10(-5)) between mtDNA and morphology, suggesting the
presence of cyto-nuclear genomic dissociation. We show that the eight
African elephant continent-wide datasets compared, including that of
Debruyne (2005), together support a two-species model with cyto-nuclear
genomic dissociation rather than a one-species model, and together
indicate that Africa harbors two species of elephant
Rohland, N.,
Malaspinas, A.S., Pollack, J.L., Slatkin, M., Matheus, P., 2007.
Proboscidean mitogenomics: Chronology and mode of elephant evolution
using mastodon as outgroup. PLoS Biol 5, e207.
doi:10.1371/journal.pbio.0050207.
Abstract: We have sequenced the complete mitochondrial genome of the
extinct American mastodon (Mammut americanum) from an Alaskan fossil
that is between 50,000 and 130,000 y old, extending the age range of
genomic analyses by almost a complete glacial cycle. The sequence we
obtained is substantially different from previously reported partial
mastodon mitochondrial DNA sequences. By comparing those partial
sequences to other proboscidean sequences, we conclude that we have
obtained the first sequence of mastodon DNA ever reported. Using the
sequence of the mastodon, which diverged 24-28 million years ago (mya)
from the Elephantidae lineage, as an outgroup, we infer that the
ancestors of African elephants diverged from the lineage leading to
mammoths and Asian elephants approximately 7.6 mya and that mammoths and
Asian elephants diverged approximately 6.7 mya. We also conclude
that the nuclear genomes of the African savannah and forest elephants
diverged approximately 4.0 mya, supporting the view that these two
groups represent different species. Finally, we found the mitochondrial
mutation rate of proboscideans to be roughly half of the rate in
primates during at least the last 24 million years.
Sreekumar,
E., Janki, M.B., Arathy, D.S., Hariharan, R., Premraj, C.A., Rasool,
T.J., 2007. Molecular characterization and expression of
interferon-gamma of Asian elephant (Elephas maximus). Vet. Immunol.
Immunopathol. 118, 75-83.
Abstract: Tuberculosis (TB) caused by Mycobacterial organisms has
emerged as one of the major diseases in captive elephants. In vitro
Interferon-gamma (IFN-gamma) assay is being used as an ancillary test
for early detection of TB in domestic and captive wild animals. In the
present study, basic sequence information and immunological
cross-reactivity of this major cytokine of Asian elephants were
explored. At predicted amino acid level, IFN-gamma of Asian elephant
showed maximum identity to that of horse (73%). Other IFN-gamma amino
acid sequences that showed high level identity were that of giant panda
(72%), dog (71%), nine-banded armadillo (69%), cattle (63%) and human
(62%). IFN-gamma promoter sequences of Asian elephant, human, cattle and
mouse showed high level conservation of the putative transcription
factor binding sites, TATA box and transcriptional start site. The
functionally important human IFN-gamma promoter elements, such as
AP-2IRE-BE, YY1-gammaIFN-BED, ATFCS and AP-1gammaINF binding sites, were
absolutely conserved in the corresponding elephant sequence. There was
only a single nucleotide variation in the other two important elements,
NFAT-gammaINF and IFN-gammaPE, indicating the highly conserved
regulation of IFN-gamma expression across different species.
Phylogenetic analysis based on IFN-gamma protein sequences revealed a
closer relation of Asian elephants and nine-banded armadillo. This shows
a closer evolution of these members of Afrotheria and Xenarthra,
respectively; and supports the previous reports based on mitochondrial
DNA studies. In Western blot analysis, IFN-gamma of Asian elephant
expressed in Escherichia coli was detected using an anti-bovine IFN-gamma
monoclonal antibody, indicating immunological cross-reactivity
Tabuce, R.,
Marivaux, L., Adaci, M., Bensalah, M., Hartenberger, J.L., Mahboubi, M.,
Mebrouk, F., Tafforeau, P., Jaeger, J.J., 2007. Early Tertiary mammals
from North Africa reinforce the molecular Afrotheria clade. Proc. Biol.
Sci. 274, 1159-1166.
Abstract: The phylogenetic pattern and timing of the radiation of
mammals, especially the geographical origins of major crown clades, are
areas of controversy among molecular biologists, morphologists and
palaeontologists. Molecular phylogeneticists have identified an
Afrotheria clade, which includes several taxa as different as tenrecs (Tenrecidae),
golden moles (Chrysochloridae), elephant-shrews (Macroscelididae),
aardvarks (Tubulidentata) and paenungulates (elephants, sea cows and
hyracoids). Molecular data also suggest a Cretaceous African origin for
Afrotheria within Placentalia followed by a long period of endemic
evolution on the Afro-Arabian continent after the mid-Cretaceous
Gondwanan breakup (approx. 105-25 Myr ago). However, there was no
morphological support for such a natural grouping so far. Here, we
report new dental and postcranial evidence of Eocene stem hyrax and
macroscelidid from North Africa that, for the first time, provides a
congruent phylogenetic view with the molecular Afrotheria clade. These
new fossils imply, however, substantial changes regarding the historical
biogeography of afrotheres. Their long period of isolation in Africa, as
assumed by molecular inferences, is now to be reconsidered inasmuch as
Eocene paenungulates and elephant-shrews are here found to be related to
some Early Tertiary Euramerican 'hyopsodontid condylarths' (archaic
hoofed mammals). As a result, stem members of afrotherian clades are not
strictly African but also include some Early Paleogene Holarctic mammals
Weiss, B.,
Faus, H., Haendler, B., 2007. Phylogenetic conservation of the androgen
receptor AR45 variant form in placental mammals. Gene 399,
105-111.
Abstract: A cDNA coding for a tissue-specific AR45 variant form of the
androgen receptor (AR) has recently been identified in humans, with
highest expression levels found in heart. The deduced protein comprises
the DNA-binding domain, hinge region and ligand-binding domain of the
AR, but not the N-terminal domain which is replaced by a unique, short,
seven amino-acid-long stretch. This sequence is encoded by the mutually
exclusive exon 1B, located between exons 1 and 2 of the human AR gene.
As transcript variants of the steroid receptor family have been shown to
have important implications for hormone function, we set out to analyse
the genomes of different organisms for potential AR45 expression. We
found exon 1B to be conserved in the syntenic chromosomal region of
non-human primates such as the chimpanzee Pan troglodytes, the
orang-utan Pongo pygmaeus, the macaque Macaca mulatta and the marmoset
Callithrix jacchus, and of the elephant Loxondonta africana, the pig Sus
scrofa and the dog Canis familiaris. Quantification of AR45 transcript
levels in heart, skeletal muscle and lung of Macaca fascicularis showed
the heart to be the main organ of expression. A complete AR45 cDNA was
furthermore isolated from the heart of this species. Comparative
analysis of the identified AR45 exon 1B regions and of the deduced amino
acids revealed a high conservation among species. The four N-terminal
residues were identical in all eight species, whereas a few changes were
seen in the other three residues in the marmoset, elephant and pig. In
contrast, we observed more divergence in the mouse Mus musculus and rat
Rattus norvegicus syntenic regions. Here a stop codon was found
downstream of the potential start codon in the putatively deduced
protein sequence and it can be inferred that no protein corresponding to
AR45 exists in these two species. The existence of AR45 in different
placental mammals with the exception of mouse and rat suggests a
disappearance in rodents late in evolution, before the separation of the
mouse and rat lineages, about 16 million years ago. In view of the
potential function of AR45 as a regulator of AR function, and
considering the multiple roles of androgens in normal physiology and in
several diseases, these findings have important implications with regard
to subtle differences in the action of the male sexual hormone in
various organisms
Wellehan, J.F.,
Johnson, A.J., Childress, A.L., Harr, K.E., Isaza, R., 2007. Six novel
gammaherpesviruses of Afrotheria provide insight into the early
divergence of the Gammaherpesvirinae. Vet Microbiol 2007 Aug 19; [Epub
ahead of print].
Abstract: The Afrotheria represent an early branching of placental
mammals. Only two herpesviruses from Afrotheria have been previously
identified, and the genus Proboscivirus in the subfamily
Betaherpesvirinae has been proposed for them. Six novel
gammaherpesviruses were identified in four species in the superorder
Afrotheria by detection and analysis of their DNA polymerase genes.
Elephantid herpesvirus 3 (ElHV3) and Elephantid herpesvirus 4 (ElHV4)
were identified from conjunctival swabs from Asian elephants (Elephas
maximus). ElHV3 was also found
in a vaginal swab from one elephant with vaginitis. Elephantid
herpesvirus 5 (ElHV5) was identified from vaginal swabs of two Asian
elephants with vaginal plaques. Elephantid herpesvirus 6 was discovered
in a conjunctival swab from an African elephant (Loxodonta africana).
Procavid herpesvirus 1 (PrHV1) was found in spleen and conjunctival
swabs of rock hyrax (Procavia capensis). Trichechid herpesvirus 1
(TrHV1) was identified from skin and buffy coats of Florida manatees (Trichechus
manatus latirostris). ElHV3 and ElHV4 form a distinct cluster, and
ElHV5, ElHV6, TrHV1, and PrHV1 form a second cluster. These viruses may
have codiverged with their host species. Phylogenetic analysis of these
novel herpesviruses suggests that two separate groups of
gammaherpesviruses may have codiverged with the Afrotheria.
Archie, E.A.,
Moss, C.J., Alberts, S.C., 2006. The ties that bind: genetic relatedness
predicts the fission and fusion of social groups in wild African
elephants
490. Proc. Biol. Sci. 273, 513-522.
Abstract: Many social animals live in stable groups. In contrast,
African savannah elephants (Loxodonta africana) live in unusually fluid,
fission-fusion societies. That is, 'core' social groups are composed of
predictable sets of individuals; however, over the course of hours or
days, these groups may temporarily divide and reunite, or they may fuse
with other social groups to form much larger social units. Here, we test
the hypothesis that genetic relatedness predicts patterns of group
fission and fusion among wild, female African elephants. Our study of a
single Kenyan population spans 236 individuals in 45 core social groups,
genotyped at 11 microsatellite and one mitochondrial DNA (mtDNA) locus.
We found that genetic relatedness predicted group fission; adult females
remained with their first order maternal relatives when core groups
fissioned temporarily. Relatedness also predicted temporary fusion
between social groups; core groups were more likely to fuse with each
other when the oldest females in each group were genetic relatives.
Groups that shared mtDNA haplotypes were also significantly more likely
to fuse than groups that did not share mtDNA. Our results suggest that
associations between core social groups persist for decades after the
original maternal kin have died. We discuss these results in the context
of kin selection and its possible role in the evolution of elephant
sociality
Bojesen,
A.M., Olsen, K.E., Bertelsen, M.F., 2006. Fatal enterocolitis in Asian
elephants (Elephas maximus) caused by Clostridium difficile
456. Vet. Microbiol. 116, 329-335.
Abstract: Two cases of fatal enteritis caused by Clostridium difficile
in captive Asian elephants are reported from an outbreak affecting five
females in the same zoo. Post mortem examination including
histopathology demonstrated fibrinonecrotic enterocolitis. C. difficile
was isolated by selective cultivation from two dead and a third severely
affected elephant. Four isolates were obtained and found positive for
toxin A and B by PCR. All isolates were positive in a toxigenic culture
assay and toxin was demonstrated in the intestinal content from one of
the fatal cases and in a surviving but severely affected elephant. PCR
ribotyping demonstrated that the C. difficile isolates shared an
identical profile, which was different from an epidemiologically
unrelated strain, indicating that the outbreak was caused by the same C.
difficile clone. It is speculated that the feeding of large quantities
of broccoli, a rich source of sulforaphane, which has been shown to
inhibit the growth of many intestinal microorganisms may have triggered
a subsequent overgrowth by C. difficile. This is the first report of C.
difficile as the main cause of fatal enterocolitis in elephants. The
findings emphasize the need to regard this organism as potentially
dangerous for elephants and caution is recommended concerning antibiotic
treatment and feeding with diets containing antimicrobials, which may
trigger an expansion of a C. difficile population in the gut
Capelli, C.,
MacPhee, R.D., Roca, A.L., Brisighelli, F., Georgiadis, N., O'Brien, S.J.,
Greenwood, A.D., 2006. A nuclear DNA phylogeny of the woolly mammoth (Mammuthus
primigenius)
468. Mol. Phylogenet. Evol. 40, 620-627.
Cooper, A.,
2006. The year of the mammoth. PLoS Biology 4, 1-3.
Abstract: Mammoth mitochondrial (mt) genomes are apparently on a similar
schedule to London buses-you wait for ages and then suddenly three come
along at once. Within the past six weeks, three studies [1-3] have
independently determined all, or most, of the mammoth mt genome
sequence, some 16,800 base pairs (bp). Encouragingly, the partial
sequence was a byproduct of a study that generated some 13 million bp of
mammoth genomic DNA using a new, massively parallel sequencing approach.
The very divergent methods used in these three studies also neatly
represent the past, present, and future of ancient DNA (aDNA) research.
aDNA methods provide an opportunity to characterise the genetic
composition of species and populations in the past, and to actually
observe evolutionary change through real time. Such a record has great
potential to reveal the processes that have generated the diversity and
distribution of taxa in our modern environment, and to examine phenomena
such as speciation, domestication, morphological evolution, and the
impacts of major environmental changes. aDNA data also provide an
important opportunity to test our ability to accurately reconstruct
evolutionary history via the fossil record or via extrapolation from the
genetic data of modern species. Unfortunately, the potential of aDNA
remains largely untapped because research has been severely limited by
the technical diffi culties of retrieving and studying the trace amounts
of highly fragmented DNA that survive in ancient specimens.
Cooper, D.W.,
Larsen, E., 2006. Immunocontraception of mammalian wildlife: Ecological
and immunogenetic issues. Reproduction 132, 821-828.
Abstract: Immunocontraception involves stimulating immune responses
against gametes or reproductive hormones thus preventing conception. The
method is being developed for the humane control of pest and
overabundant populations of mammalian wildlife. This paper examines
three fundamental issues associated with its use: (1) the difficulties
of obtaining responses to self-antigens, (2) the likely evolution of
genetically based non-response to immunocontraceptive agents, and (3)
the possible changes in the array of pathogens possessed by the target
species after generations of immunocontraception. Our review of the
literature demonstrates that the barriers to an effective
immunocontraceptive are at present very basic. Should they be overcome,
the effects of immunocontraception on the immunogenetic constitution of
wildlife populations through the selection for nonresponders must be
examined. We suggest that the attempt to use the animal's own immune
system to modulate reproduction may be incompatible with the basic
biological function of protection against infectious disease. Research
programs on mammalian immunocontraception should involve measurement of
the heritability of non-response and an assessment of the likely change
in the response of the contracepted population to possible pathogens.
Ducummon,
C.C., Berger, T., 2006. Localization of the Rho GTPases and some Rho
effector proteins in the sperm of several mammalian species
440. Zygote. 14, 249-257.
Abstract: The acrosome reaction is a fundamental event in the biology of
the sperm and is a prerequisite to fertilization of the egg. Members of
the Rho family of GTPases and their effectors are present in the
cytoplasm and/or plasma membrane overlying the acrosome of porcine
sperm. We have implicated the Rho family of GTPases and the
Rho-activated kinase, ROCK-1, in mediating the zona-pellucida-induced
acrosome reaction. Others have implicated the Rho GTPase in regulating
the ionophore-induced acrosome reaction in the sperm of several
mammalian species as well as in motility of bovine sperm. In this study,
the localization of the Rho GTPases (RhoA, RhoB, Rac1 and Cdc42) as well
as the effectors RhoGDI, PI(4)P5K and ROCK-1, was determined in boar,
human, rat, ram, bull and elephant sperm. The four GTPases were each
present in the sperm head of all species examined. RhoGDI was expressed
in the head and tail of sperm from all species except pig, where it was
present only in the head. PI(4)P5K was expressed in both head and tail
of sperm from all species, but expression was typically weaker in the
tail. Finally, ROCK-1 was expressed in the heads and tails of all sperm
except that of the boar, where it was present only in the acrosomal
region. These observations taken together suggest that the expression of
Rho GTPases in sperm has been conserved throughout mammalian evolution,
most likely due to the role of these GTPases in regulating acrosomal
exocytosis
Eckhart, L.,
Uthman, A., Sipos, W., Tschachler, E., 2006. Genome sequence comparison
reveals independent inactivation of the caspase-15 gene in different
evolutionary lineages of mammals
428. Molecular Biology and Evolution 23, 2081-2089.
Abstract: We have recently demonstrated that placental mammalian species
such as pig and dog express a novel proapoptotic protease, caspase-15,
whereas mouse and humans lack this enzyme. Here we investigated the
evolutionary fate of the caspase-15 gene in different mammalian lineages
by analyzing whole-genome shotgun sequences of 30 mammalian species for
the presence of caspase-15 orthologs. Caspase-15 gene sequences were
found in representatives of all major mammalian clades except for the
superorders Afrotheria (tenrec, rock hyrax, and elephant) and
Euarchontoglires (rodents, rabbit, tree shrew, and primates), which
either lacked any caspase-15-like sequences or contained mutated
remnants of the caspase-15 gene. Polymerase chain reaction screenings
confirmed the results of the database searches and showed that the
caspase-15 gene is expressed not only in various placental mammals but
also in the marsupial, Monodelphis domestica. The observed species
distribution implies that caspase-15 has originated in an early ancestor
of modern mammals and has been conserved, over more than 180 Myr, in
marsupials and many placental mammals, whereas it was independently lost
in 2 phylogenetically distant clades of placental mammals, that is,
Afrotheria and Euarchontoglires. Our data suggest that the inactivation
of the caspase-15 gene was not counteracted by, and may even have been
driven by, evolutionary constraints in these clades, and therefore,
caution against the uncritical use of gene absence for the inference of
phylogenetic relationships
Fischer,
M.S., Blickhan, R., 2006. The tri-segmented limbs of therian mammals:
kinematics, dynamics, and self-stabilization--a review
397. J. Exp. Zool. A Comp Exp. Biol. 305, 935-952.
Abstract: The evolution of therian mammals is to a large degree marked
by changes in their motion systems. One of the decisive transitions has
been from the sprawled, bi-segmented to the parasagittal, tri-segmented
limb. Here, we review aspects of the tri-segmented limb in locomotion
which have been elucidated in our research groups in the last 10 years.
First, we report the kinematics of the tri-segmented therian limb from
mouse to elephant in order to explore general principles of the therian
limb configuration and locomotion. Torques will be reported from a
previous paper (Witte et al., 2002. J Exp Biol 205:1339-1353) for a
better understanding of the anti-gravity work of all limb joints. The
stability of a limb in z-configuration will be explained and its
advantage with respect to other potential solutions from modeling will
be discussed. Finally, we describe how the emerging concept of
self-stability can be explained for a tri-segmented leg template and how
it affects the design of the musculoskeletal system and the operation of
legs during locomotion. While locomotion has been considered as mainly a
control problem in various disciplines, we stress the necessity to
reduce control as much as possible. Central control can be cheap if the
limbs are "intelligent" by means of their design. Gravity-induced
movements and self-stability seem to be energy-saving mechanisms
Gee, H.,
2006. Evolution: memories of mammoths
505. Nature 439, 673.
Gelvin-Reymiller, C., Reuther, J.D., Potter, B.A., Bowers, P.M., 2006.
Technical aspects of a worked proboscidean tusk from Inmachuk River,
Seward Peninsula, Alaska. Journal of Archaeological Science 33,
1088-1094.
Abstract: Prehistoric reduction sequences of proboscidean ivory have
been described and discussed within the Russian and European Upper
Paleolithic archaeological literature. A culturally modified
proboscidean tusk (Mammuthus sp.) in Seward Peninsula, northwestern
Alaska, displays longitudinal grooving, providing an insight into a
reduction technique rarely described within North American
archaeological literature. Similar reduction sequences have been
described for the production of bone, antler and walrus ivory artifacts
in the North American prehistoric record; however, examples on
proboscidean ivory are extremely rare.
Henderson,
D.M., 2006. Burly gaits: Centers of mass, stability, and the trackways
of sauropod dinosaurs. Journal of Vertebrate Paleontology 26,
907-921.
Abstract: The narrow- and wide-gauge trackways attributed to sauropod
dinosaurs are hypothesized to be a consequence of the relative positions
of their centers of mass. This hypothesis was tested using
three-dimensional, trackwayproducing computer models of two sauropods
and studies of Asian elephants. Centers of mass of sauropod models were
computed using density distributions that reflect the high degree of
pneumatization of the skeletons and air sacs within the body. A close
correspondence was found between the relative areas of hand and foot
prints in different trackways and the relative fractions of the body
weight borne by the forefeet and hindfeet in the different types of
sauropods inferred to have made the trackways. Experimental studies of
Asian elephants corroborated the close correspondence between relative
areas of the hindfeet and forefeet and body weight distribution.
Replicating actual sauropod trackways with the walking models enabled
testing of proposed gaits for a sauropod model. Brachiosaurus brancai,
with its more centrally positioned center of mass, was stable and
possessed a wide safety margin only when replicating a wide trackway.
Conversely, Diplodocics carnegii, with a more posteriorly placed center
of mass, was most stable when replicating a narrow trackway. A trend for
large sauropods (> 12 tons), independent of clade, to have more
anteriorly positioned centers of mass was identified, and it is proposed
that all large sauropods were restricted to producing wide-gauge
trackways for stability reasons. The primitive gait state for
Sauropodomorpha was determined to be one that produced narrow-gauge
trackways.
Hilborn, R.,
Arcese, P., Borner, M., Hando, J., Hopcraft, G., Loibooki, M., Mduma,
S., Sinclair, A.R., 2006. Effective enforcement in a conservation area
378. Science 314, 1266.
Abstract: Wildlife within protected areas is under increasing threat
from bushmeat and illegal trophy trades, and many argue that enforcement
within protected areas is not sufficient to protect wildlife. We
examined 50 years of records from Serengeti National Park in Tanzania
and calculated the history of illegal harvest and enforcement by park
authorities. We show that a precipitous decline in enforcement in 1977
resulted in a large increase in poaching and decline of many species.
Conversely, expanded budgets and antipoaching patrols since the
mid-1980s have greatly reduced poaching and allowed populations of
buffalo, elephants, and rhinoceros to rebuild
Hofreiter,
M., Lister, A., 2006. Mammoths
459. Curr. Biol. 16, R347-R348.
Joubert, D.,
2006. Hunting behaviour of lions (Panthera leo) on elephants (Loxodonta
africana) in the Chobe National Park, Botswana. African Journal of
Ecology 44, 279-281.
Abstract: Megaherbivores like elephants and rhinos have been regarded as
invulnerable to predation as adults (Owen-Smith, 1988; G. B. Schaller
pers. comm.), although Guthrie (1990) suggests that lions hunted such
large prey during the Pleistocene. Recently, there have been a number of
observations of elephants killed by lions in northern Botswana, going as
far back as 1985 (M. Slogrove pers. comm.). The hunting behaviour of
lions on elephants, and the age and sex structure of the elephants
killed, were observed at a waterhole in the Savute region of Chobe
National Park. The first observed elephant kill was recorded in August
1991. Systematic records of elephants killed were made between 1993 and
1996.
Kalmykov, N.P.,
Mashchenko, E.N., 2006. New data on the migration of the family
Elephantidae (Mammalia, Proboscidea) in Eurasia
480. Dokl. Biol. Sci. 406, 103-105.
Krause, J.,
Dear, P.H., Pollack, J.L., Slatkin, M., Spriggs, H., Barnes, I., Lister,
A.M., Ebersberger, I., Paabo, S., Hofreiter, M., 2006. Multiplex
amplification of the mammoth mitochondrial genome and the evolution of
Elephantidae
533. Nature 439, 724-727.
Abstract: In studying the genomes of extinct species, two principal
limitations are typically the small quantities of endogenous ancient DNA
and its degraded condition, even though products of up to 1,600 base
pairs (bp) have been amplified in rare cases. Using small overlapping
polymerase chain reaction products, longer stretches of sequences or
even whole mitochondrial genomes can be reconstructed, but this approach
is limited by the number of amplifications that can be performed from
rare samples. Thus, even from well-studied Pleistocene species such as
mammoths, ground sloths and cave bears, no DNA sequences of more than
about 1,000 bp have been reconstructed. Here we report the complete
mitochondrial genome sequence of the Pleistocene woolly mammoth
Mammuthus primigenius. We used about 200 mg of bone and a new approach
that allows the simultaneous retrieval of multiple sequences from small
amounts of degraded DNA. Our phylogenetic analyses show that the mammoth
was more closely related to the Asian than to the African elephant.
However, the divergence of mammoth, African and Asian elephants occurred
over a short time, corresponding to only about 7% of the total length of
the phylogenetic tree for the three evolutionary lineages
Larke, A.,
Crews, D.E., 2006. Parental investment, late reproduction, and increased
reserve capacity are associated with longevity in humans. J Physiol
Anthropol 25, 119-131.
Abstract: Throughout the living world trade-offs between reproductive
success and longevity have been observed. In general, two extremes of
life history patterning are reported, r- and K-selected species. The
latter tend toward larger body sizes, few offspring from any one
pregnancy, few offspring over the female reproductive span, longer life
spans, and greater parental investment (PI: all efforts and expenses
associated with the production, gestation, post-natal care, feeding, and
protection of young) (e.g., whales, elephants, hominids). r-selected
species tend toward smaller body size, multiple births/litters per
pregnancy, female production of many gametes and offspring over the life
span, and low levels of PI (e.g., most plants, insects, mice). These
differences have significant influences on physiological variation among
human populations.Across human samples, reproductive success (RS: the
number of offspring successfully birthed and reared to reproductive age)
has been reported to vary positively, negatively, and not at all with
longevity of women. This complexity may be in part due to the fact that
both early-life and late-life fecundity are associated with longevity in
women, while total parity seems a poor gauge of female longevity in
humankind. Large variations in associations of RS with longevity in
women suggest that multiple factors may confound this association. One
confounding factor is that among women, RS is largely determined not by
fecundity, but by the quality of PI available to offspring. Among modern
humans, PI is more complex, longer lasting (both relatively and
absolutely), and extensive than for any other ammal. This suggests that
modern human life history is a reflection of the co-evolution of
longevity and extensive PI as part of our species' biocultural
evolution. The need for long-term PI has greatly shaped human
physiological variation and patterns of longevity.
Lyashchenko,
K.P., Greenwald, R., Esfandiari, J., Olsen, J.H., Ball, R., Dumonceaux,
G., Dunker, F., Buckley, C., Richard, M., Murray, S., Payeur, J.B.,
Andersen, P., Pollock, J.M., Mikota, S., Miller, M., Sofranko, D.,
Waters, W.R., 2006. Tuberculosis in elephants: antibody responses to
defined antigens of Mycobacterium tuberculosis, potential for early
diagnosis, and monitoring of treatment
438. Clin. Vaccine Immunol. 13, 722-732.
Abstract: Tuberculosis (TB) in elephants is a re-emerging zoonotic
disease caused primarily by Mycobacterium tuberculosis. Current
diagnosis relies on trunk wash culture, the only officially recognized
test, which has serious limitations. Innovative and efficient diagnostic
methods are urgently needed. Rapid identification of infected animals is
a crucial prerequisite for more effective control of TB, as early
diagnosis allows timely initiation of chemotherapy. Serology has
diagnostic potential, although key antigens have not been identified and
optimal immunoassay formats are not established. To characterize the
humoral responses in elephant TB, we tested 143 serum samples collected
from 15 elephants over time. These included 48 samples from five
culture-confirmed TB cases, of which four were in Asian elephants
infected with M. tuberculosis and one was in an African elephant with
Mycobacterium bovis. Multiantigen print immunoassay (MAPIA) employing a
panel of 12 defined antigens was used to identify serologic correlates
of active disease. ESAT-6 was the immunodominant antigen recognized in
elephant TB. Serum immunoglobulin G antibodies to ESAT-6 and other
proteins were detected up to 3.5 years prior to culture of M.
tuberculosis from trunk washes. Antibody levels to certain antigens
gradually decreased in response to antitubercular therapy, suggesting
the possibility of treatment monitoring. In addition to MAPIA, serum
samples were evaluated with a recently developed rapid test (RT) based
on lateral flow technology (ElephantTB STAT-PAK). Similarly to MAPIA,
infected elephants were identified using the RT up to 4 years prior to
positive culture. These findings demonstrate the potential for TB
surveillance and treatment monitoring using the RT and MAPIA,
respectively
Perelygin,
A.A., Lear, T.L., Zharkikh, A.A., Brinton, M.A., 2006. Comparative
analysis of vertebrate EIF2AK2 (PKR) genes and assignment of the equine
gene to ECA15q24-q25 and the bovine gene to BTA11q12-q15
416. Genet. Sel Evol. 38, 551-563.
Abstract: The structures of the canine, rabbit, bovine and equine
EIF2AK2 genes were determined. Each of these genes has a 5' non-coding
exon as well as 15 coding exons. All of the canine, bovine and equine
EIF2AK2 introns have consensus donor and acceptor splice sites. In the
equine EIF2AK2 gene, a unique single nucleotide polymorphism that
encoded a Tyr329Cys substitution was detected. Regulatory elements
predicted in the promoter region were conserved in ungulates, primates,
rodents, Afrotheria (elephant) and Insectifora (shrew). Western clawed
frog and fugu EIF2AK2 gene sequences were detected in the USCS Genome
Browser and compared to those of other vertebrate EIF2AK2 genes. A
comparison of EIF2AK2 protein domains in vertebrates indicates that the
kinase catalytic domains were evolutionarily more conserved than the
nucleic acid-binding motifs. Nucleotide substitution rates were uniform
among the vertebrate sequences with the exception of the zebrafish and
goldfish EIF2AK2 genes, which showed substitution rates about 20% higher
than those of other vertebrates. FISH was used to physically assign the
horse and cattle genes to chromosome locations, ECA15q24-q25 and
BTA11q12-15, respectively. Comparative mapping data confirmed
conservation of synteny between ungulates, humans and rodents
Plotnik, J.M.,
de Waal, F.B., Reiss, D., 2006. Self-recognition in an Asian elephant
389. Proc. Natl. Acad. Sci. U. S. A 103, 17053-17057.
Abstract: Considered an indicator of self-awareness, mirror
self-recognition (MSR) has long seemed limited to humans and apes. In
both phylogeny and human ontogeny, MSR is thought to correlate with
higher forms of empathy and altruistic behavior. Apart from humans and
apes, dolphins and elephants are also known for such capacities. After
the recent discovery of MSR in dolphins (Tursiops truncatus), elephants
thus were the next logical candidate species. We exposed three Asian
elephants (Elephas maximus) to a large mirror to investigate their
responses. Animals that possess MSR typically progress through four
stages of behavior when facing a mirror: (i) social responses, (ii)
physical inspection (e.g., looking behind the mirror), (iii) repetitive
mirror-testing behavior, and (iv) realization of seeing themselves.
Visible marks and invisible sham-marks were applied to the elephants'
heads to test whether they would pass the litmus "mark test" for MSR in
which an individual spontaneously uses a mirror to touch an otherwise
imperceptible mark on its own body. Here, we report a successful MSR
elephant study and report striking parallels in the progression of
responses to mirrors among apes, dolphins, and elephants. These
parallels suggest convergent cognitive evolution most likely related to
complex sociality and cooperation
Poinar, H.N.,
Schwarz, C., Qi, J., Shapiro, B., MacPhee, R.D., Buigues, B., Tikhonov,
A., Huson, D.H., Tomsho, L.P., Auch, A., Rampp, M., Miller, W.,
Schuster, S.C., 2006. Metagenomics to paleogenomics: large-scale
sequencing of mammoth DNA
529. Science 311, 392-394.
Abstract: We sequenced 28 million base pairs of DNA in a metagenomics
approach, using a woolly mammoth (Mammuthus primigenius) sample from
Siberia. As a result of exceptional sample preservation and the use of a
recently developed emulsion polymerase chain reaction and pyrosequencing
technique, 13 million base pairs (45.4%) of the sequencing reads were
identified as mammoth DNA. Sequence identity between our data and
African elephant (Loxodonta africana) was 98.55%, consistent with a
paleontologically based divergence date of 5 to 6 million years. The
sample includes a surprisingly small diversity of environmental DNAs.
The high percentage of endogenous DNA recoverable from this single
mammoth would allow for completion of its genome, unleashing the field
of paleogenomics
Poulakakis,
N., Parmakelis, A., Lymberakis, P., Mylonas, M., Zouros, E., Reese,
D.S., Glaberman, S., Caccone, A., 2006. Ancient DNA forces
reconsideration of evolutionary history of Mediterranean pygmy
elephantids. Biol. Lett. 2, 451-454.
Abstract: During the Pleistocene pygmy elephantids, some only a quarter
of their ancestors' size, were present on Mediterranean islands until
about 10,000 years ago (y.a.). Using a new methodology for ancient DNA (aDNA)
studies, the whole genomic multiple displacement amplification method,
we were able to retrieve cytochrome b (cytb) DNA fragments from 4200 to
800,000 y.a. specimens from island and mainland samples, including pygmy
and normal-sized forms. The short DNA sequence (43 bp) retrieved from
the 800,000 y.a. sample is one of the oldest DNA fragment ever
retrieved. Duplication of the experiments in two laboratories, the
occurrence of three diagnostic sites and the results of the phylogenetic
analyses strongly support its authenticity. Our results challenge the
prevailing view that pygmy elephantids of the eastern Mediterranean
originated exclusively from Elephas, suggesting independent histories of
dwarfism and the presence of both pygmy mammoths and elephant-like taxa
on these islands. Based on our molecular data, the origin of the Tilos
and Cyprus elephantids from a lineage within the genus Elephas is
confirmed, while the DNA sequence from the Cretan sample falls clearly
within the mammoth clade. Thus, the name Mammuthus creticus rather than
Elephas creticus, seems to be justified for this form. Our findings also
suggest a need to re-evaluate the evolutionary history of the
Sicilian/Maltese species, traditionally included in the genus Elephas
Rogaev, E.I.,
Moliaka, Y.K., Malyarchuk, B.A., Kondrashov, F.A., Derenko, M.V.,
Chumakov, I., Grigorenko, A.P., 2006. Complete mitochondrial genome and
phylogeny of Pleistocene mammoth Mammuthus primigenius
507. PLoS. Biol. 4, e73.
Abstract: Phylogenetic relationships between the extinct woolly mammoth
(Mammuthus primigenius), and the Asian (Elephas maximus) and African
savanna (Loxodonta africana) elephants remain unresolved. Here, we
report the sequence of the complete mitochondrial genome (16,842 base
pairs) of a woolly mammoth extracted from permafrost-preserved remains
from the Pleistocene epoch--the oldest mitochondrial genome sequence
determined to date. We demonstrate that well-preserved mitochondrial
genome fragments, as long as approximately 1,600-1700 base pairs, can be
retrieved from pre-Holocene remains of an extinct species. Phylogenetic
reconstruction of the Elephantinae clade suggests that M. primigenius
and E. maximus are sister species that diverged soon after their common
ancestor split from the L. africana lineage. Low nucleotide diversity
found between independently determined mitochondrial genomic sequences
of woolly mammoths separated geographically and in time suggests that
north-eastern Siberia was occupied by a relatively homogeneous
population of M. primigenius throughout the late Pleistocene
Rompler, H.,
Rohland, N., Lalueza-Fox, C., Willerslev, E., Kuznetsova, T., Rabeder,
G., Bertranpetit, J., Schoneberg, T., Hofreiter, M., 2006. Nuclear gene
indicates coat-color polymorphism in mammoths
439. Science 313, 62.
Abstract: By amplifying the melanocortin type 1 receptor from the woolly
mammoth, we can report the complete nucleotide sequence of a
nuclear-encoded gene from an extinct species. We found two alleles and
show that one allele produces a functional protein whereas the other one
encodes a protein with strongly reduced activity. This finding suggests
that mammoths may have been polymorphic in coat color, with both dark-
and light-haired individuals co-occurring
Rothschild,
B.M., Martin, L.D., 2006. Did ice-age bovids spread tuberculosis?
Naturwissenschaften 93, 565-569.
Abstract: Pathognomonic metacarpal undermining is a skeletal pathology
that has been associated with Mycobacterium tuberculosis in bovids.
Postcranial artiodactyl, perissodactyl, and carnivore skeletons were
examined in major university and museum collections of North America and
Europe for evidence of this and other pathology potentially attributable
to tuberculosis. Among nonproboscidean mammals from pre-Holocene North
America, bone lesions indicative of tuberculosis were restricted to
immigrant bovids from Eurasia. No bone lesions compatible
with diagnosis of tuberculosis were found in large samples of other
pre-Holocene (164 Oligocene, 397 Miocene, and 1,041 Plio-Pleistocene)
North American mammals, including
114 antilocaprids. Given the unchanged frequency of bovid tubercular
disease during the Pleistocene, it appears that most did not die from
the disease but actually reached an
accommodation with it (as did the mastodon) (Rothschild and Laub 2006).
Thus, they were sufficiently long-lived to assure greater spread of the
disease. The relationships of the
proboscidean examples need further study, but present evidence suggests
a Holarctic spread of tuberculosis during the Pleistocene, with bovids
acting as vectors. While the role of other animals in the transmission
of tuberculosis could be considered, the unique accommodation achieved
by bovids and mastodons makes them the likely "culprits" in its spread.
Rothschild,
B.M., Laub, R., 2006. Hyperdisease in the late Pleistocene:validation of
an early 20th century hypothesis. Naturwissenschaften 93,
557-564.
Rubenstein,
D.R., Sherman, P.W., Gavin, T.A., 2006. Pleistocene park: Does
re-wilding North America represent sound conservation for the 21st
century? Biological Conservation 132, 232-238.
Abstract: A group of conservation biologists recently proposed to
populate western North America with African and Asian megafauna,
including lions, elephants, cheetahs, and camels, to create a facsimile
of a species assemblage that disappeared from the continent some 13,000
years ago. The goals of this program, known as "Pleistocene re-wilding",
are to restore some of the evolutionary and ecological potential that
was lost from North America during the Pleistocene extinctions, and help
prevent the extinction of selected African and Asian mammals.
Pleistocene re-wilders justify this conservation strategy on ethical and
aesthetic grounds, arguing that humans have a moral responsibility to
make amends for overexploitation by our ancestors. They believe that the
flora of many North American terrestrial ecosystems has gone basically
unchanged since the end of the Pleistocene, so re-wilding would help
restore evolutionary and ecological potential and improve ecosystem
functioning. This paper discusses some of the pros and cons of this
proposal, including the ethical, aesthetic, ecological, and evolutionary
issues, assesses its potential economic and political impacts on other
conservation practices, both in North America and elsewhere, and reviews
the realities of large mammal reintroductions. It is concluded that
Pleistocene re-wilding with exotic species will not restore the
evolutionary or ecological potential of native North American species
nor extinct Pleistocene megafauna and their ancient ecosystems, but may
instead jeopardize indigenous species and North American ecosystems.
Resources would be better spent on preserving threatened organisms in
their native habitats and reintroducing them to places in their
historical ranges from which they were only recently extirpated.
Schmitt, D.,
Cartmill, M., Griffin, T.M., Hanna, J.B., Lemelin, P., 2006. Adaptive
value of ambling gaits in primates and other mammals
460. J. Exp. Biol. 209, 2042-2049.
Abstract: At speeds between the walk and the gallop, most mammals trot.
Primates almost never trot, and it has been claimed that they transition
directly from a walk to a gallop without any distinctive mid-speed
running gait. If true, this would be another characteristic difference
between the locomotion of primates and that of most other quadrupedal
mammals. Presently, however, few data exist concerning the actual
presence or absence of intermediate-speed gaits (i.e. gaits that are
used between a walk and a gallop) in primates. Video records of running
in twelve primate species reveal that, unlike most other mammals, all
the primates studied almost exclusively adopt an 'amble'--an
intermediate-speed running gait with no whole-body aerial phase--rather
than trot. Ambling is also common in elephants and some horses, raising
the question of why ambling is preferred over trotting in these diverse
groups of animals. Mathematical analyses presented here show that
ambling ensures continuous contact of the body with the substrate while
dramatically reducing vertical oscillations of the center of mass. This
may explain why ambling appears to be preferable to trotting for
extremely large terrestrial mammals such as elephants and for arboreal
mammals like primates that move on unstable branches. These findings
allow us to better understand the mechanics of these unusual running
gaits and shed new light on primate locomotor evolution
Shoshani, J.,
Kupsky, W.J., Marchant, G.H., 2006. Elephant brain. Part I: gross
morphology, functions, comparative anatomy, and evolution
446. Brain Res. Bull. 70, 124-157.
Abstract: We report morphological data on brains of four African,
Loxodonta africana, and three Asian elephants, Elephas maximus, and
compare findings to literature. Brains exhibit a gyral pattern more
complex and with more numerous gyri than in primates, humans included,
and in carnivores, but less complex than in cetaceans. Cerebral frontal,
parietal, temporal, limbic, and insular lobes are well developed,
whereas the occipital lobe is relatively small. The insula is not as
opercularized as in man. The temporal lobe is disproportionately large
and expands laterally. Humans and elephants have three parallel temporal
gyri: superior, middle, and inferior. Hippocampal sizes in elephants and
humans are comparable, but proportionally smaller in elephant. A
possible carotid rete was observed at the base of the brain. Brain size
appears to be related to body size, ecology, sociality, and longevity.
Elephant adult brain averages 4783 g, the largest among living and
extinct terrestrial mammals; elephant neonate brain averages 50% of its
adult brain weight (25% in humans). Cerebellar weight averages 18.6% of
brain (1.8 times larger than in humans). During evolution,
encephalization quotient has increased by 10-fold (0.2 for extinct
Moeritherium, approximately 2.0 for extant elephants). We present 20
figures of the elephant brain, 16 of which contain new material.
Similarities between human and elephant brains could be due to
convergent evolution; both display mosaic characters and are highly
derived mammals. Humans and elephants use and make tools and show a
range of complex learning skills and behaviors. In elephants, the large
amount of cerebral cortex, especially in the temporal lobe, and the
well-developed olfactory system, structures associated with complex
learning and behavioral functions in humans, may provide the substrate
for such complex skills and behavior
Shoshani, J.,
Kupsky, W.J., Marchant, G.H., 2006. Elephant brain. Part I: gross
morphology, functions, comparative anatomy, and evolution. Brain Res
Bull 70, 124-157.
Abstract: We report morphological data on brains of four African,
Loxodonta africana, and three Asian elephants, Elephas maximus, and
compare findings to literature. Brains exhibit a gyral pattern more
complex and with more numerous gyri than in primates, humans included,
and in carnivores, but less complex than in cetaceans. Cerebral frontal,
parietal, temporal, limbic, and insular lobes are well developed,
whereas the occipital lobe is relatively small. The insula is not as
opercularized as in man. The temporal lobe is disproportionately large
and expands laterally. Humans and elephants have three parallel temporal
gyri: superior, middle, and inferior. Hippocampal sizes in elephants and
humans are comparable, but proportionally smaller in elephant. A
possible carotid rete was observed at the base of the brain. Brain size
appears to be related to body size, ecology, sociality, and longevity.
Elephant adult brain averages 4783 g, the largest among living and
extinct terrestrial mammals; elephant neonate brain averages 50% of its
adult brain weight (25% in humans). Cerebellar weight averages 18.6% of
brain (1.8 times larger than in humans). During evolution,
encephalization quotient has increased by 10-fold (0.2 for extinct
Moeritherium, approximately 2.0 for extant elephants). We present 20
figures of the elephant brain, 16 of which contain new material.
Similarities between human and elephant brains could be due to
convergent evolution; both display mosaic characters and are highly
derived mammals. Humans and elephants use and make tools and show a
range of complex learning skills and behaviors. In elephants, the large
amount of cerebral cortex, especially in the temporal lobe, and the
well-developed olfactory system, structures associated with complex
learning and behavioral functions in humans, may provide the substrate
for such complex skills and behavior.
Shoshani, J.,
Walter, R.C., Abraha, M., Berhe, S., Tassy, P., Sanders, W.J., Marchant,
G.H., Libsekal, Y., Ghirmai, T., Zinner, D., 2006. A proboscidean from
the late Oligocene of Eritrea, a "missing link" between early
Elephantiformes and Elephantimorpha, and biogeographic implications
384. Proc. Natl. Acad. Sci. U. S. A 103, 17296-17301.
Abstract: We report on a late Oligocene proboscidean species from
Eritrea, dated to 26.8 +/- 1.5 Mya. This "missing link" between early
elephantiformes and Elephantimorpha is the oldest known nongomphothere
proboscidean to probably display horizontal tooth displacement, typical
of elephants [Elephantimorpha consists of Mammutida (mastodons) and
Elephantida, and Elephantida includes gomphotheres, stegodons, and
elephants]. Together with the newly discovered late Oligocene
gomphotheres from Chilga, Ethiopia, the Eritrean taxon points to the
importance of East Africa as a major area for the knowledge of the early
evolution of Elephantimorpha before the faunal exchange between Eurasia
and Africa
Shoshani, J.,
Walter, R.C., Abraha, M., Berhe, S., Tassy, P., Sanders, W.J., Marchant,
G.H., Libsekal, Y., Ghirmai, T., Zinner, D., 2006. A proboscidean from
the late Oligocene of Eritrea, a "missing link" between early
Elephantiformes and Elephantimorpha, and biogeographic implications.
Proc Natl Acad Sci U S A. 103, 17296-17301pdf.
Abstract: We report on a late Oligocene proboscidean species from
Eritrea, dated to 26.8 +/- 1.5 Mya. This "missing link" between early
elephantiformes and Elephantimorpha is the oldest known nongomphothere
proboscidean to probably display horizontal tooth displacement, typical
of elephants [Elephantimorpha consists of Mammutida (mastodons) and
Elephantida, and Elephantida includes gomphotheres, stegodons, and
elephants]. Together with the newly discovered late Oligocene
gomphotheres from Chilga, Ethiopia, the Eritrean taxon points to the
importance of East Africa as a major area for the knowledge of the early
evolution of Elephantimorpha before the faunal exchange between Eurasia
and Africa.Department of Biology, University of Asmara, PO Box 1220,
Asmara, Eritrea. jshosh@sun.science.wayne.edu
Uni, S.,
Bain, O., Agatsuma, T., Katsumi, A., Baba, M., Yanai, T., Takaoka, H.,
2006. New filarial nematode from Japanese serows (Naemorhedus crispus:
Bovidae) close to parasites from elephants
403. Parasite 13, 193-200.
Abstract: A new onchocercid species, Loxodontofilaria caprini n. sp. (Filarioidea:
Nematoda), found in subcutaneous tissues of 37 (33%) of 112 serows (Noemorhedus
crispus) examined in Japan, is described. The female worm had the
characteristics of Loxodontofilaria, e.g., the large body size,
well-developed esophagus with a shallow buccal cavity, and the long tail
with three caudal lappets. The male worm of the new species, which was
first described in the genus, had unequal length of spicules, 10 pairs
of pre- and post-caudal papillae, and three terminal caudal lappets.
Deirids were present in both sexes. Among four species of the genus
loxodontofiloria: one from the hippopotamus and three from the
Elepantidae, L. caprini n. sp. appears close to L. asiatica Bain, Baker
& Chabaud, 1982, a subcutaneous parasite of Elephas indicus in Myanmar
(Burma). However, L. caprini n. sp. is distinct from L. asiatica in that
the Japanese female worm has an esophagus half as long and the
microfilariae also half as long with a coiled posterior. The
microfilariae were found in the skin of serows. The new parasite appears
to clearly illustrate a major event in the evolution of onchocercids:
the host-switching. This might have occurred on the Eurasian continent,
where elephantids and the lineage of rupicaprines diversified during the
Pliocene-Pleistocene, or in Japan, into which some of these hosts
migrated
Vinogradov,
I.V., Kochneva, G.V., Shchelkunov, S.N., Riabchikova, E.I., 2006.
[Reproduction of cowpox virus strain EP-2 isolated from an elephant in
primary fibroblast cultures and chorion-allantoic chick embryos]
451. Vopr. Virusol. 51, 44-48.
Abstract: Electron microscopy was used to study the reproduction of
cowpox virus strain EP-2 in the cells of a primary fibroblast cultures (PFC)
and chorion-allantoic membrane (CAM) of chick embryos (CE). The
sequential stages of viral morphogenesis and the structure of A-type
inclusions were described. The parameters of viral reproduction in PFC
and CE CAM were compared. The formation of crystalloid tubular
structures in PFC, unusual electron dense inclusions in the cells of CE
CAN, and different variants of A-type inclusions in the cells of a pock
was found. The histological and ultrastructural characteristics of pocks
in CE CAM are described
Agnew, D.W.,
Hagey, L., Shoshani, J., 2005. The elephants of Zoba Gash Barka,
Eritrea: part 4. Cholelithiasis in a wild African elephant (Loxodonta
africana). J. Zoo. Wildl. Med. 36, 677-683.
Abstract: A 4.0-kg cholelith was found within the abdominal cavity of a
dead wild African elephant (Loxodonta africana) in Eritrea. Analysis of
this cholelith by histochemistry, electron microscopy, electrospray mass
spectroscopy, and energy-dispersive x-ray spectroscopy revealed it was
composed of bile alcohols but no calcium, bilirubin, or cholesterol.
Bacteria were also found in the cholelith. Similar, but smaller, bile
stones have been identified previously in other wild African elephants
and an excavated mammoth (Mammuthus columbi). Choleliths have been
reported only once in a captive Asian elephant (Elephas maximus).
Elephants, along with hyraxes (Procavia capensis) and manatees (Trichechus
manatus), are unique among mammals in producing only bile alcohols and
no bile acids, which may predispose them to cholelithiasis, particularly
in association with bacterial infection. Dietary factors may also play
an important role in cholelith formation.
Debruyne, R.,
2005. A case study of apparent conflict between molecular phylogenies:
the interrelationships of African elephants. Cladistics 21,
31-50.
Abstract: Recent molecular phylogenies of the African elephants suggest
that there is an evolutionary structure within Loxodonta africana.
Some nuclear results (Roca et al., 2001) support the separation of the
forest African elephant subspecies L. a. cyclotis as a species
distinct from the savannah elephant L. a. africana, on the basis
of the recognition of both forming highly divergent (reciprocally
monophyletic) clades. Conversely, a mitochondrial survey (Eggert et al.,
2002), while admitting a geographic partitioning of the genetic
structure within African elephants, suggests retaining the status quo.
They recognize three diagnosible entities (western, central and
south-eastern Africa) with non-overlapping ranges within L. africana
sensu lato. In order to address these con.icting views (historical
fragmentation and speciation or isolation by distance, respectively), we
have sequenced two datasets of 1961 bp (for 50 elephants) and about 3700
bp, respectively (for 20 elephants) of the mitochondrial DNA for both
forms of elephants (cyclotis and africana). They span the
cytochrome b gene, the control region and several RNAs. When compared
with former mtDNA data, they provide the most comprehensive view of the
African elephant phylogeny (78 mtDNA haplotypes, of which 44 are new)
and provide the .rst insight into populations from the Democratic
Republic of Congo. The genetic diversity of mtDNA was appraised and the
stability of alternative phylogenetic trees was investigated. Our
results are inconsistent with both those prior studies. They revealed
two highly divergent molecular clades referred to as F and S, that do
not conform to the morphological delineations of cyclotis and
africana. A non-negligible proportion of specimens of L. a.
africana display haplotypes prevailing in forest elephant
populations (clade F). The geographic distribution of clades and areas
of their co-occurrence support the hypothesis of incomplete isolation
between forest and savannah African elephant populations, followed by
recurrent interbreeding between the two forms. We state that the
conclusions of prior studies resulted from insufficient character and /
or geographic sampling. We conclude that there is no satisfying argument
which can recognize two or more species of African elephants. We briefly
comment on the meaning of such an attitude in a conservation viewpoint.
Delves, P.J.,
Roitt, I.M., 2005. Vaccines for the control of reproduction--status in
mammals, and aspects of comparative interest
592. Dev. Biol. (Basel) 121, 265-273.
Abstract: The objective of producing vaccines which target elements of
the reproductive system to control fertility has been pursued for many
years. Of the many targets for such vaccines, several sperm-associated
antigens have been proposed for antibody-mediated intervention before
fertilization but the very abundance of antigen to be neutralized has
been a barrier. Zona pellucida antigens associated with the surface of
the oocyte have also been targeted and used successfully for control of
'wild' elephant populations but worries concerning immunopathologically-mediated
tissue damage have been mooted. Vaccines using human chorionic
gonadotropin (hCG) which is required for the implantation and
maintenance of the fertilized egg, although of interest for the
development of fertility control in human populations, has no relevance
in the context of the present conference because external fertilization
of fish eggs is independent. The pathways by which gonadotropin-releasing
hormone (GnRH) secreted by the hypothalamus promote release of
luteinizing (LH) and follicle-stimulating hormone (FSH) which govern the
physiological maturation and maintenance of the reproductive organs,
provide many targets for immunological intervention. Most consistent
success has been reported using GnRH-based vaccines which are
immunosterilizing in a variety of mammalian species such as pigs,
rodents and white-tailed deer. The fact that the structure of the
decapeptide, GnRH, has been maintained over so many years of evolution
and been conserved across so many animal species, encourages the view
that a strategy for control of sexual maturation in fish based upon
stimulation of GnRH antibodies may well prove to be a practical
proposition, provided the formulation of an appropriate highly
immunogenic vaccine can be achieved
Edwards, H.G.,
Jorge Villar, S.E., Nik Hassan, N.F., Arya, N., O'Connor, S., Charlton,
D.M., 2005. Ancient biodeterioration: an FT-Raman spectroscopic study of
mammoth and elephant ivory
576. Anal. Bioanal. Chem. 383, 713-720.
Abstract: Raman spectra of mammoth ivory specimens have been recorded
using near-infrared excitation, and comparisons made with modern Asian
and African elephant ivories. Whereas the most ancient mammoth ivory
(60-65 ky) showed no evidence for an organic collagen component, more
recent samples of mammoth ivory indicated that some preservation had
occurred, although with biodeterioration of the protein structure
exhibited by the amide I and III bands in the 1200-1700 cm(-1) region of
the Raman spectrum. The consequent difficulties encountered when
applying chemometrics methods to ancient ivory analysis (which are
successful for modern specimens) are noted. In the most ancient mammoth
ivory specimens, which are extensively fragmented, evidence of
mineralization is seen, with the production of gypsum, calcite and
limonite; Raman microscopic analysis of crystalline material inside the
fissures of the mammoth ivory shows the presence of gypsum as well as
cyanobacterial colonisation. The application of Raman spectroscopy to
the nondestructive analysis of archaeological materials in order to gain
information of relevance to their preservation or restoration is
highlighted
Edwards,
H.G.M., Hassan, N.F.N., Arya, N., 2005. Evaluation of Raman spectroscopy
and application of chemometric methods for the differentiation of
contemporary ivory specimens I: elephant and mammalian species. Journal
of Raman Spectroscopy 37, 353-360.
Abstract: Specimens of mammoth, African and Asian ivory dentine, and
other mammalian species were examined using Fourier-Transform (FT),
conventional dispersive (confocal) and remote-sensing portable Raman
spectroscopy, all with near-infrared laser excitation (1064 and 785 nm).
FT-Raman spectroscopy produced the best quality spectra for
differentiation purposes and the application of a fibre probe coupled to
a portable Raman spectrometer has also been demonstrated and proposed
for the in situ characterization of suspected contraband ivories
at airports. In addition to the visual comparison of spectral features,
chemometric methods are used to discriminate between African and Asian
elephant dentine by analyzing normalized integrated band areas in ten
selected wavenumber regions. Principal component analysis separates the
spectra of both species into two well-defined groups based upon their
organic and inorganic composition. By means of stepwise discriminant
analysis almost 98% of the spectra are correctly classified to their
species group memberships.
Gibbons, A.,
2005. Ancient DNA. New methods yield mammoth samples
527. Science 310, 1889.
Glickman,
S.E., Short, R.V., Renfree, M.B., 2005. Sexual differentiation in three
unconventional mammals: spotted hyenas, elephants and tammar wallabies
566. Horm. Behav. 48, 403-417.
Abstract: The present review explores sexual differentiation in three
non-conventional species: the spotted hyena, the elephant and the tammar
wallaby, selected because of the natural challenges they present for
contemporary understanding of sexual differentiation. According to the
prevailing view of mammalian sexual differentiation, originally proposed
by Alfred Jost, secretion of androgen and anti-Mullerian hormone (AMH)
by the fetal testes during critical stages of development accounts for
the full range of sexually dimorphic urogenital traits observed at
birth. Jost's concept was subsequently expanded to encompass sexual
differentiation of the brain and behavior. Although the central focus of
this review involves urogenital development, we assume that the novel
mechanisms described in this article have potentially significant
implications for sexual differentiation of brain and behavior, a
transposition with precedent in the history of this field. Contrary to
the "specific" requirements of Jost's formulation, female spotted hyenas
and elephants initially develop male-type external genitalia prior to
gonadal differentiation. In addition, the administration of
anti-androgens to pregnant female spotted hyenas does not prevent the
formation of a scrotum, pseudoscrotum, penis or penile clitoris in the
offspring of treated females, although it is not yet clear whether the
creation of masculine genitalia involves other steroids or whether there
is a genetic mechanism bypassing a hormonal mediator. Wallabies, where
sexual differentiation occurs in the pouch after birth, provide the most
conclusive evidence for direct genetic control of sexual dimorphism,
with the scrotum developing only in males and the pouch and mammary
glands only in females, before differentiation of the gonads. The
development of the pouch and mammary gland in females and the scrotum in
males is controlled by genes on the X chromosome. In keeping with the
"expanded" version of Jost's formulation, secretion of androgens by the
fetal testes provides the best current account of a broad array of sex
differences in reproductive morphology and endocrinology of the spotted
hyena, and androgens are essential for development of the prostate and
penis of the wallaby. But the essential circulating androgen in the male
wallaby is 5alpha androstanediol, locally converted in target tissues to
DHT, while in the pregnant female hyena, androstenedione, secreted by
the maternal ovary, is converted by the placenta to testosterone (and
estradiol) and transferred to the developing fetus. Testicular
testosterone certainly seems to be responsible for the behavioral
phenomenon of musth in male elephants. Both spotted hyenas and elephants
display matrilineal social organization, and, in both species, female
genital morphology requires feminine cooperation for successful
copulation. We conclude that not all aspects of sexual differentiation
have been delegated to testicular hormones in these mammals. In
addition, we suggest that research on urogenital development in these
non-traditional species directs attention to processes that may well be
operating during the sexual differentiation of morphology and behavior
in more common laboratory mammals, albeit in less dramatic fashion
Glickman,
S.E., Short, R.V., Renfree, M.B., 2005. Sexual differentiation in three
unconventional mammals: Spotted hyenas, elephants and tammar wallabies.
Hormones and Behaviour 48, 403-417.
Abstract: The present review explores sexual differentiation in three
non-conventional species: the spotted hyena, the elephant and the tammar
wallaby, selected because of the natural challenges they present for
contemporary understanding of sexual differentiation. According to the
prevailing view of mammalian sexual differentiation, originally proposed
by Alfred Jost, secretion of androgen and anti-Mullerian hormone (AMH)
by the fetal testes during critical stages of development accounts for
the full range of sexually dimorphic urogenital traits observed at
birth. Jost's concept was subsequently expanded to encompass sexual
differentiation of the brain and behavior. Although the central focus of
this review involves urogenital development, we assume that the novel
mechanisms described in this article have potentially significant
implications for sexual differentiation of brain and behavior, a
transposition with precedent in the history of this field. Contrary to
the ''specific'' requirements of Jost's formulation, female spotted
hyenas and elephants initially develop male-type external genitalia
prior to gonadal differentiation. In addition, the administration of
anti-androgens to pregnant female spotted hyenas does not prevent the
formation of a scrotum, pseudoscrotum, penis or penile clitoris in the
offspring of treated females, although it is not yet clear whether the
creation of masculine genitalia involves other steroids or whether there
is a genetic mechanism bypassing a hormonal mediator. Wallabies, where
sexual differentiation occurs in the pouch after birth, provide the most
conclusive evidence for direct genetic control of sexual dimorphism,
with the scrotum developing only in males and the pouch and mammary
glands only in females, before differentiation of the gonads. The
development of the pouch and mammary gland in females and the scrotum in
males is controlled by genes on the X chromosome. In keeping with the
''expanded'' version of Jost's formulation, secretion of androgens by
the fetal testes provides the best current account of a broad array of
sex differences in reproductive morphology and endocrinology of the
spotted hyena, and androgens are essential for development of the
prostate and penis of the wallaby. But the essential circulating
androgen in the male wallaby is 5α
androstanediol, locally converted in target tissues to DHT, while in the
pregnant female hyena, androstenedione, secreted by the maternal ovary,
is converted by the placenta to testosterone (and estradiol) and
transferred to the developing fetus. Testicular testosterone certainly
seems to be responsible for the behavioral phenomenon of musth in male
elephants. Both spotted hyenas and elephants display matrilineal social
organization, and, in both species, female genital morphology requires
feminine cooperation for successful copulation. We conclude that not all
aspects of sexual differentiation have been delegated to testicular
hormones in these mammals. In addition, we suggest that research on
urogenital development in these non-traditional species directs
attention to processes that may well be operating during the sexual
differentiation of morphology and behavior in more common laboratory
mammals, albeit in less dramatic fashion.
Hambler, C.,
Henderson, P.A., Speight, M.R., 2005. Elephants, Ecology and
Nonequilibrium? Science 307, 673c-674c.
Abstract: Elephants and thrips may have something in common: It has been
proposed that elephants in Africa do not reach carrying capacity because
they inhabit "nonequilibrium" ecosystems with highly variable rainfall
("Space-the final frontier for economists and elephants," E. Bulte et
al., Perspectives, 15 Oct., p. 420). Similarly, it has been proposed
that thrips in Australia do not reach a carrying capacity because of
climatic fluctuations. The nonequilibrium (density-independent) ideas of
the 1950s are being reworked as "state-of-the-art" ecological theory by
Bulte et al. We should remember, however, that a more
sophisticated analysis of the same thrip populations revealed strongly
density dependent population change and hence a carrying capacity. The
suggestion that multispecies systems are unlikely to show density
dependence is erroneous. In contrast, evidence is emerging of the very
widespread occurrence of density dependence, even in complex marine
systems. Detection of such effects typically takes over four
generations; well over a hundred years might be needed to detect density
dependence in an elephant population. The application of nonequilibrium
hypotheses to savannah has been challenged on theoretical and empirical
grounds. Models indicate that herbivores in semi-arid areas are in
long-term equilibrium with a subset of their resources. Competitive
regulation is now very clear in a number of species of large herbivores
in Africa, including wildebeest. A review concluded there was no
evidence of a paradigm shift to a nonequilibrium perspective among those
researching grasslands. Large species are unlikely to exhibit
metapopulation dynamics. The harvesting of elephants is, rightly,
controversial. We suggest that the nonequilibrium perspective is
unlikely to clarify how their populations might respond to management.
Kalmykov, N.P.,
Maschenko, E.N., 2005. The oldest representative of Elephantidae (Mammalia,
Proboscidea) in Asia. Paleontological Journal 39, 652-659.
Abstract: The earliest representative of the family Elephantidae in
Asia, Archidiskodon sp. From the Udunga locality (western Transbaikalia,
Early Pliocene, MN 15), is described. The age of the accompanying mammal
fauna suggests simultaneous migrations of mammuthoid elephants from
Africa to Europe and Asia. The material includes a right dp(3) and
isolated tooth plates from another dp(3). The structure of dp(3)
indicates that the Early Pliocene members of Elephantidae from western
Transbaikalia displayed the basic morphological features of this family,
i.e., the successive formation of dp(3), plate number, hypsodonty, and
enamel thickness.
Larsen, R.S.,
Kay, M., Triantis, J., Salman, M.D. Update on serological detection of
Mycobacterium tuberculosis infection in Asian elephants. 2005
Proceedings AAZV, AAWV, AZA Nutrition Advisory Group. 62-63. 2005.
Ref Type: Conference Proceeding
Abstract: Tuberculosis has become an important disease in captive
elephants, particularly Asian elephants (Elephas maximus). Diagnosing
tuberculosis in elephants has been problematic as many tests have
inadequate sensitivity or specificity.2-4 A multiple-antigen
enzyme-linked immunosorbent assay (ELISA) was previously investigated
for detecting infection in Asian elephants and African elephants
(Loxodonta africana); this test had excellent sensitivity and
specificity, but needed further evaluation.1 Modifications to the
multiple-antigen ELISA panel have since been made. Valuable antigens
were retained, other antigens were removed, and new ones were added.
This modified ELISA was re-evaluated, using serum from 68 Asian
elephants. Sixteen had M. tuberculosis -positive trunk cultures, while
52 were either culture negative at necropsy or had a history of negative
trunk cultures and no contact with infected elephants. Seven elephants
were evaluated over time. The test was 100% (95% CI; 95-100%) specific
and 94% (95% CI; 79-100%) sensitive using two of the six antigens (M.
bovis strain AN5 culture filtrate and M. tuberculosis early secretory
antigenic target 6). "Effectively-treated" elephants had decreasing
seroreactivity, but those that were culture-positive post-treatment were
more consistently seroreactive. Although "effectivelytreated" elephants
had declining seroreactivity, they still usually had higher values than
animals that had never been infected. Serology continues to show great
promise in detecting tuberculosis in elephants, often detecting
infection months-to-years sooner than trunk wash culture. Advances in
techniques may soon make serology even more practical. While serology
should not replace trunk-wash culture, it is a useful adjunct for early
detection of infection in elephants and for monitoring treatment.
ACKNOLWEDGMENTS We thank the many veterinarians, owners, caretakers, and
managers of elephant-owning institutions that participated in this
investigation, as well as Drs. Michele Miller and Susan Mikota for
helping to coordinate sample collection. We also thank Kimberly Deines
and other laboratory personnel who processed ELISA samples. The study
was partially funded by a grant from USDA, CSREES to Colorado State
University Program of Economically Important Infectious Animal Diseases.
LITERATURE CITED
1.Larsen, R.S., M.D. Salman, S.K. Mikota, R. Isaza, R.J. Montali, and J.
Triantis. 2000. Evaluation of a multiple-antigen enzyme-linked
immunosorbent assay for detection of Mycobacterium tuberculosis in
captive elephants. J. Zoo Wildl. Med. 31: 291-302.
2. Mikota, S.K., L. Peddie, J. Peddie, R. Isaza, F. Dunker, G. West, W.
Lindsay, R.S. Larsen, M.D. Salman, D. Chatterjee, J. Payeur, D. Whipple,
C. Thoen, D.S. Davis, R.J. Montali and J. Maslow. 2001. Epidemiology
and diagnosis of Mycobacterium tuberculosis in six groups of elephants.
J. Zoo Wildl. Med. 32: 1-16.
3. Mikota, S.K., R.S. Larsen, and R.J. Montali. 2000. Tuberculosis in
elephants in North America. Zoo Biol. 19: 393-403.
4. U.S. Department of Agriculture. 2003. Guidelines for the control of
tuberculosis in elephants. Animal and Plant Health Inspection Service;
Animal Care. Washington, D.C. http://www.aphis.usda.gov/ac/TBGuidelines2003.pdf.
Lewerin,
S.S., Olsson, S.L., Eld, K., Roken, B., Ghebremichael, S., Koivula, T.,
Kallenius, G., Bolske, G., 2005. Outbreak of Mycobacterium tuberculosis
infection among captive Asian elephants in a Swedish zoo
637. Veterinary Record 156, 171-175.
Abstract: Between 2001 and 2003, there was an outbreak of tuberculosis
in a Swedish zoo which involved elephants, giraffes, rhinoceroses and
buffaloes. Cultures of trunk lavages were used to detect infected
elephants, tuberculin testing was used in the giraffes and buffaloes,
and tracheal lavage and tuberculin testing were used in the
rhinoceroses. The bacteria isolated were investigated by spoligotyping
and restriction fragment length polymorphism. Five elephants and one
giraffe were found to have been infected by four different strains of
Mycobacterium tuberculosis
Loannidis,
J.P.A., 2005. Why most published research findings are false. PLoS Med 2,
e124.
Nishihara,
H., Satta, Y., Nikaido, M., Thewissen, J.G., Stanhope, M.J., Okada, N.,
2005. A retroposon analysis of Afrotherian phylogeny
600. Molecular Biology and Evolution 22, 1823-1833.
Abstract: Recent comprehensive studies of DNA sequences support the
monophyly of Afrotheria, comprising elephants, sirenians (dugongs and
manatees), hyraxes, tenrecs, golden moles, aardvarks, and elephant
shrews, as well as that of Paenungulata, comprising elephants, sirenians,
and hyraxes. However, phylogenetic relationships among paenungulates, as
well as among nonpaenungulates, have remained ambiguous. Here we applied
an extensive retroposon analysis to these problems to support the
monophyly of aardvarks, tenrecs, and golden moles, with elephant shrews
as their sister group. Regarding phylogenetic relationships in
Paenungulata, we could characterize only one informative locus, although
we could isolate many insertions specific to each of three lineages,
namely, Proboscidea, Sirenia, and Hyracoidea. These data prompted us to
reexamine phylogenetic relationships among Paenungulata using 19 nuclear
gene sequences resulting in three different analyses, namely, short
interspersed element (SINE) insertions, nuclear sequence analyses, and
morphological cladistics, supporting different respective phylogenies.
We concluded that these three lineages diverged very rapidly in a very
short evolutionary period, with the consequence that ancestral
polymorphism present in the last common ancestor of Paenungulata results
in such incongruence. Our results suggest the rapid fixation of many
large-scale morphological synapomorphies for Tethytheria; implications
of this in relation to the morphological evolution in Paenungulata are
discussed
Palombo, M.R.,
Ferretti, M.P., 2005. Elephant fossil record from Italy: Knowledge,
problems, and perspectives. Quaternary International 126-28,
107-136.
Abstract: The earliest occurrence of elephantines in Italy is in the
middle Villafranchian (late Middle Pliocene; ca. 2.6 Ma), with a
primitive representative of the mammoth lineage. In addition to this
still poorly known taxon, four elephant species are clearly recognized
in Plio-Pleistocene fossil mammal assemblages from the Italian
peninsula: Mammuthus meridionalis, M. trogontherii, M.
primigenius, and Elephas (Palaeoloxodon) antiquus. In Sicily,
at least three different taxa are present during the Pleistocene: the
dwarf E. falconeri, the medium sized E. (P.) "mnaidriensis",
and a third poorly known large sized taxon, represented by isolated
findings, in some cases apparently associated with E. (P.) "mnaidriensis".
A number of specimens from Spinagallo and Luparello, of intermediate
size between E. "mnaidriensis" and E falconeri, suggest
the occurrence in Sicily of a further elephant species. Sardinia records
the only case of an endemic small sized Mammuthus species from
the western Mediterranean. The Italian elephant fossil recordclearly
shows the influence of climatic, physiographic and paleogeographic
conditions on the pattern of occurrence and dispersal of this mammal
group in Southern Europe.
Perez-Barberia,
F.J., Gordon, I.J., 2005. Gregariousness increases brain size in
ungulates
586. Oecologia. 145, 41-52.
Abstract: The brain's main function is to organise the physiological and
behavioural responses to environmental and social challenges in order to
keep the organism alive. Here, we studied the effects that
gregariousness (as a measurement of sociality), dietary habits,
gestation length and sex have on brain size of extant ungulates. The
analysis controlled for the effects of phylogeny and for random
variability implicit in the data set. We tested the following groups of
hypotheses: (1) Social brain hypothesis-gregarious species are more
likely to have larger brains than non-gregarious species because the
former are subjected to demanding and complex social interactions; (2)
Ecological hypothesis-dietary habits impose challenging cognitive tasks
associated with finding and manipulating food (foraging strategy); (3)
Developmental hypotheses (a) energy strategy: selection for larger
brains operates, primarily, on maternal metabolic turnover (i.e.
gestation length) in relation to food quality because the majority of
the brain's growth takes place in utero, and finally (b) sex hypothesis:
females are expected to have larger brains than males, relative to body
size, because of the differential growth rates of the soma and brain
between the sexes. We found that, after adjusting for body mass,
gregariousness and gestation length explained most of the variation in
brain mass across the ungulate species studied. Larger species had
larger brains; gregarious species and those with longer gestation
lengths, relative to body mass, had larger brains than non-gregarious
species and those with shorter gestation lengths. The effect of diet was
negligible and subrogated by gestation length, and sex had no
significant effect on brain size. The ultimate cause that could have
triggered the co-evolution between gestation length and brain size
remains unclear
Pichardo, M.,
2005. Taxonomic revision of Central Mexican mammoths in Paleoindian
sites
522. Anthropol. Anz. 63, 409-413.
Abstract: Central Mexican mammoth species taxonomy has been based on the
quotient Molar length/Number of dental plates, which sorted three
species, Mammuthus imperator, columbi and ?jeffersonii. New evidence
from skull morphology sorts only two subspecies, M. columbi columbi and
M. columbi felicis as being present during Paleoindian time
Roca, A.L.,
O'Brien, S.J., 2005. Genomic inferences from Afrotheria and the
evolution of elephants
558. Curr. Opin. Genet. Dev. 15, 652-659.
Abstract: Recent genetic studies have established that African forest
and savanna elephants are distinct species with dissociated cytonuclear
genomic patterns, and have identified Asian elephants from Borneo and
Sumatra as conservation priorities. Representative of Afrotheria, a
superordinal clade encompassing six eutherian orders, the African
savanna elephant was among the first mammals chosen for whole-genome
sequencing to provide a comparative understanding of the human genome.
Elephants have large and complex brains and display advanced levels of
social structure, communication, learning and intelligence. The elephant
genome sequence might prove useful for comparative genomic studies of
these advanced traits, which have appeared independently in only three
mammalian orders: primates, cetaceans and proboscideans
Roca, A.L.,
Georgiadis, N., O'Brien, S.J., 2005. Cytonuclear genomic dissociation in
African elephant species
650. Nat. Genet. 37 , 96-100.
Abstract: African forest and savanna elephants are distinct species
separated by a hybrid zone. Because hybridization can affect the
systematic and conservation status of populations, we examined gene flow
between forest and savanna elephants at 21 African locations. We
detected cytonuclear dissociation, indicative of different evolutionary
histories for nuclear and mitochondrial genomes. Both paternally (n =
205 males) and biparentally (n = 2,123 X-chromosome segments) inherited
gene sequences indicated that there was deep genetic separation between
forest and savanna elephants. Yet in some savanna locales distant from
present-day forest habitats, many individuals with savanna-specific
nuclear genotypes carried maternally transmitted forest elephant
mitochondrial DNA. This extreme cytonuclear dissociation implies that
there were ancient episodes of hybridization between forest females and
savanna males, which are larger and reproductively dominant to forest or
hybrid males. Recurrent backcrossing of female hybrids to savanna bulls
replaced the forest nuclear genome. The persistence of residual forest
elephant mitochondria in savanna elephant herds renders evolutionary
interpretations based on mitochondrial DNA alone misleading and
preserves a genomic record of ancient habitat changes.
Roth, G.,
Dicke, U., 2005. Evolution of the brain and intelligence
612. Trends Cogn Sci. 9, 250-257.
Abstract: Intelligence has evolved many times independently among
vertebrates. Primates, elephants and cetaceans are assumed to be more
intelligent than 'lower' mammals, the great apes and humans more than
monkeys, and humans more than the great apes. Brain properties assumed
to be relevant for intelligence are the (absolute or relative) size of
the brain, cortex, prefrontal cortex and degree of encephalization.
However, factors that correlate better with intelligence are the number
of cortical neurons and conduction velocity, as the basis for
information-processing capacity. Humans have more cortical neurons than
other mammals, although only marginally more than whales and elephants.
The outstanding intelligence of humans appears to result from a
combination and enhancement of properties found in non-human primates,
such as theory of mind, imitation and language, rather than from
'unique' properties
Shoshani, J.,
Tassy, P., 2005. Advances in proboscidean taxonomy & classification,
anatomy & physiology, and ecology & behavior. Quaternary International
126-128, 5-20.
Abstract: With the addition of 13 new taxa, we recognized 175 species
and subspecies of proboscideans, classified in 42 genera and 10
families. The three extant species are: forest African elephant (Loxodonta
cyclotis), bush African elephant (L. africana), and Asian
elephant (Elephas maximus, with three subspecies). Rigorous
analysis of characters published or awaiting publication is imperative
for better understanding of the cladistic relationships among currently
recognized proboscideans. Here we focus on ''aquatic ancestry'' of
Proboscidea, interordinal relationships within Placentalia, proboscidean
taxonomy in general and South American in particular, anatomy and
physiology and some ecological considerations. New taxa above the family
level include sister taxa Mammutida and Elephantida, and
Plesielephantiformes as a sister taxon to Elephantiformes. Neontological
research is currently under way on the hyoid apparatus, lungs, brain,
hearing, ecology and behavior. Topics for future research include:
phylogenetic positions of anthracobunids, Moeritherium,
tetralophodont gomphotheres, Stegolophodon and Stegodon,
and intra-familial relationships among Loxodonta, Elephas
and Mammuthus, and continuing studies on encephalization
quotient. Certain anatomical features and functions (e.g., the hyoid
apparatus that helps in food procurement, in production of infrasonic
sounds, and in storing water to be used in time of stress) evolved about
25 million years ago, in time for diversification into new niches when
grasses appeared in the landscape.
Sivasundaram,
S., 2005. Trading knowledge: The East India Company's elephants in India
and Britain. Historical Journal 48, 27-63.
Abstract: During the East India Company's rule of India, Britons
observed the pervasiveness of elephants in local modes of warfare,
hunting, trade, and religious symbolism. The colonizers appropriated
this knowledge about elephants: for instance, in the taking-over of
Mughal trade routes or Tipu Sultan's stables. What Indians knew about
the elephant also fed into a metropolitan culture of anthropomorphism,
exemplified in the celebrated shooting of the elephant Chuny in 1826.
Anthropomorphic approaches to the elephant held by Britons worked
alongside Sanskrit texts and Mughal paintings. These hybrid
understandings gave way, by the mid-century to an allegedly objective
and Christian science of animals, which could not be tainted by what was
called pagan superstition. By using the elephant as a point of focus,
this article urges the importance of popular traditions of colonial
exchange in the emergence of science, and cautions against the
reification of indigenous knowledge. The argument aims to show the
strengths of a history of knowledge-making that is not focused on
elites, the metropolis, or the periphery. A study of the uses of the
elephant in colonialism also suggests the multiple and easily
interchangeable meanings that animals could carry.
Stone, J.,
Telford, M., 2005. Fractal dimensions characterizing mammal teeth: A
case study involving Elephantidae. Mammal Rev. 35, 123-128.
Abstract: 1. Dental features frequently have provided data for producing
and deducing mammal taxonomies and phylogeny, yet quantitative or
statistical analyses for describing intricacies that characterize tooth
form are wanting. 2. A method for determining fractal dimensions D
that characterize enamel ridges constituting occlusal surfaces for teeth
in some mammal species is presented; D quantify complexity (i.e.
convolution). The method is exemplified with an analysis that was
conducted on teeth from the Family Elephantidae.
Stuart, A.J.,
2005. The extinction of woolly mammoth ( Mammuthus primigenius)
and straight-tusked elephant (Palaeoloxodon antiquus) in Europe.
Quaternary International 126-28, 171-177.
Abstract: Together with several other megafaunal species in Northern
Eurasia, Mammuthus primigenius and Palaeoloxodon antiquus
became extinct in the Last Glacial-Interglacial cycle, but they had very
different ecologies, times of extinction and `last stands' in different
regions. The dramatic contraction in mammoth range ca. 12 kyr (uncalibrated
C-14 chronology), after which known populations were confined to
Northern Siberia (mainly Taymyr and Wrangel Island), correlates well
with the extensive spread of trees in the Allerod phase of the Late
Glacial Interstadial. The return of open steppe-tundra in the Younger
Dryas cold phase, ca. 10.6-10 kyr, saw a limited re-expansion into NE
Europe, followed by retraction and apparent extinction of mainland
populations, which can be correlated with the marked loss of open
habitats in the early Holocene. In contrast, at the end of the Last
Interglacial, the retreat of P. antiquus to S. Europe, where it
may have survived to ca. 50-34 kyr, can be linked to the loss of
woodland habitats elsewhere. Although in both species, climate acting
through vegetational changes evidently drove these range shifts,
environmental change alone appears insufficient to account for
extinctions. However, the possible role of human hunters is also still
unclear.
Vidya, T.N.,
Fernando, P., Melnick, D.J., Sukumar, R., 2005. Population
differentiation within and among Asian elephant (Elephas maximus)
populations in southern India
675. Heredity 94, 71-80.
Abstract: Southern India, one of the last strongholds of the endangered
Asian elephant (Elephas maximus), harbours about one-fifth of the global
population. We present here the first population genetic study of
free-ranging Asian elephants, examining within- and among-population
differentiation by analysing mitochondrial DNA (mtDNA) and nuclear
microsatellite DNA differentiation across the Nilgiris-Eastern Ghats,
Anamalai, and Periyar elephant reserves of southern India. Low mtDNA
diversity and 'normal' microsatellite diversity were observed.
Surprisingly, the Nilgiri population, which is the world's single
largest Asian elephant population, had only one mtDNA haplotype and
lower microsatellite diversity than the two other smaller populations
examined. There was almost no mtDNA or microsatellite differentiation
among localities within the Nilgiris, an area of about 15,000 km2. This
suggests extensive gene flow in the past, which is compatible with the
home ranges of several hundred square kilometres of elephants in
southern India. Conversely, the Nilgiri population is genetically
distinct at both mitochondrial and microsatellite markers from the two
more southerly populations, Anamalai and Periyar, which in turn are not
genetically differentiated from each other. The more southerly
populations are separated from the Nilgiris by only a 40-km-wide stretch
across a gap in the Western Ghats mountain range. These results variably
indicate the importance of population bottlenecks, social organization,
and biogeographic barriers in shaping the distribution of genetic
variation among Asian elephant populations in southern India
Zack, S.P.,
Penkrot, T.A., Bloch, J.I., Rose, K.D., 2005. Affinities of 'hyopsodontids'
to elephant shrews and a Holarctic origin of Afrotheria
622. Nature 434, 497-501.
Abstract: Macroscelideans (elephant shrews or sengis) are small-bodied
(25-540 g), cursorial (running) and saltatorial (jumping), insectivorous
and omnivorous placental mammals represented by at least 15 extant
African species classified in four genera. Macroscelidea is one of
several morphologically diverse but predominantly African placental
orders classified in the superorder Afrotheria by molecular
phylogeneticists. The distribution of modern afrotheres, in combination
with a basal position for Afrotheria within Placentalia and molecular
divergence-time estimates, has been used to link placental
diversification with the mid-Cretaceous separation of South America and
Africa. Morphological phylogenetic analyses do not support Afrotheria
and the fossil record favours a northern origin of Placentalia. Here we
describe fossil postcrania that provide evidence for a close
relationship between North American Palaeocene-Eocene apheliscine 'hyopsodontid'
'condylarths' (early ungulates or hoofed mammals) and extant
Macroscelidea. Apheliscine postcranial morphology is consistent with a
relationship to other ungulate-like afrotheres (Hyracoidea, Proboscidea)
but does not provide support for a monophyletic Afrotheria. As the
oldest record of an afrothere clade, identification of macroscelidean
relatives in the North American Palaeocene argues against an African
origin for Afrotheria, weakening support for linking placental
diversification to the break-up of Gondwana
Zhu, M.,
Maslow, J.N., Mikota, S.K., Isaza, R., Dunker, F., Riddle, H., Peloquin,
C.A., 2005. Population pharmacokinetics of pyrazinamide in elephants
564. J. Vet. Pharmacol. Ther. 28, 403-409.
Abstract: This study was undertaken to characterize the population
pharmacokinetics (PK), therapeutic dose, and preferred route of
administration for pyrazinamide (PZA) in elephants. Twenty-three African
(Loxodonta africana) and Asian (Elephas maximus) elephants infected with
or in contact with others culture positive for Mycobacterium
tuberculosis were dosed under treatment conditions. PZA was dosed daily
at 20-30 mg/kg via oral (fasting or nonfasting state) or rectal (enema
or suppository) administration. Blood samples were collected 0-24 h
postdose. Population PK was estimated using nonlinear mixed effect
modeling. Drug absorption was rapid with T(max) at or before 2 h
regardless of the method of drug administration. C(max) at a mean dose
of 25.6 (+/-4.6) mg/kg was 19.6 (+/-9.5 microg/mL) for PZA given orally
under fasting conditions. Under nonfasting conditions at a mean dose of
26.1 +/- 4.2 mg/kg, C(max) was 25% (4.87 +/- 4.89 microg/mL) and area
under concentration curve (AUC) was 30% of the values observed under
fasting conditions. Mean rectal dose of 32.6 +/- 15.2 mg/kg yielded
C(max) of 12.3 +/- 6.3 microg/mL, but comparable AUC to PZA administered
orally while fasting. Both oral and rectal administration of PZA
appeared to be acceptable and oral dosing is preferred because of the
higher C(max) and lower inter-subject variability. A starting dose of 30
mg/kg is recommended with drug monitoring between 1 and 2 h postdose.
Higher doses may be required if the achieved C(max) values are below the
recommended 20-50 microg/mL range
Agatsuma, T.,
Rajapakse, R.P., Kuruwita, V.Y., Iwagami, M., Rajapakse, R.C., 2004.
Molecular taxonomic position of the elephant schistosome,
Bivitellobilharzia nairi, newly discovered in Sri Lanka
745. Parasitol. Int. 53, 69-75.
Abstract: Bivitellobilharzia nairi (Mudaliar and Ramanujachar, 1945)
Dutt and Srivastava, 1955 was first recorded in India. A number of adult
worm specimens of this schistosome species were recovered from a
domestic elephant, which died in 1999 in Sri Lanka. This is the first
report of this schistosome from Sri Lanka. In the present study, in
order to clarify the phylogenetic relationship with other species of
schistosomes, sequences from the second internal transcribed spacer
(ITS2) of the ribosomal gene repeat, part of the 28S ribosomal RNA gene
(28S), and part of the mitochondrial cytochrome c oxidase subunit 1
(CO1) gene from B. nairi were analyzed. Two intraspecific variations
were seen within 13 individuals in the ITS2 region. In the CO1 region of
the mitochondrial DNA, there were four haplotypes in the nucleotide
sequences and two haplotypes in the amino acid sequences. Phylogenetic
analysis using the nuclear DNA showed that B. nairi was basal to all of
species of the genus Schistosoma. The 28S tree also showed that the
mammalian lineage was monophyletic. However, phylogenetic analysis using
the mitochondrial DNA showed that B. nairi was nested within the genus
Schistosoma. The taxonomical position for this species as well as the
contradiction between the results from the nuclear and mitochondrial
genes were discussed
Alter, S.,
2004. Elephas maximus: A portrait of the Indian elephant. Harcourt
Press.
Abstract: Review from Amazon: Mixing mythology and natural history,
Stephen Alter lets readers share his lifelong love for the Indian
elephant, Elephas maximus. While legends threaten to overwhelm facts in
the tale, Alter has nonetheless presented an accurate portrait of his
subject, true to centuries of Indian tradition. Beyond metaphors and
fables, elephants occupy an important place in Sanskrit literature.
Gajashastra, or "elephant science," was studied and recorded in several
texts that are based on oral traditions.As much travelogue as science
book, Elephas inextricably links the Indian elephant with the history of
southern Asia itself. In pre-colonial India, elephants were wound up in
religion and daily life; in modern times, the animals were first hunted
then fetishized by Westerners. Alter reserves judgment on these issues,
except to note that none of India's 20th-century history has been good
for elephant populations, which are endangered or threatened nearly
everywhere. He treks into parks and reserves, seeking out wild elephants
and describing their awe-inspiring behaviors. The stories he uncovers
along the way--of temple elephants, mysterious Elephanta Island,
seagoing elephants, and the god Ganesha--weave a spellbinding tale.
--Therese Littleton
Buchanan, K.L.,
Goldsmith, A.R., 2004. Noninvasive endocrine data for behavioural
studies: The importance of validation. Animal Behaviour 67,
183-185.
Abstract: There has been a substantial growth recently in the use of
noninvasive methods to quantify hormone production, through the
measurement of excreted hormones or hormone levels from saliva, sweat or
hair (e.g.Wasser et al. 2000; Cook 2002; Pfeffer et al. 2002). These
measures can quantify either current (e.g. Berg & Wynne-Edwards 2002;
Maso et al. 2002) or past (e.g. Wasser et al. 2000; Ostner et al. 2002)
levels of hormone production and the data can be used to determine the
relations between a range of hormone levels and animal behaviour across
taxa (Wasser et al. 2000). Such techniques have been used extensively to
examine social stress (Goymann et al. 2001), the effects of
environmental stress (Creel et al. 2002), reproductive cycles (Curtis et
al. 2000) and social dominance (von Engelhardt et al. 2000; Langmore et
al. 2002). They may have important applications in conservation science
(Ishii 1999). There are several reasons why noninvasive methods of
sampling are highly desirable. Importantly, animal suffering can
potentially be reduced. In practical terms there are also several
advantages: noninvasive methods allow samples to be obtained
retrospectively, which represent average hormone production over a
certain time frame, and the time spent handling the animal does not
affect the levels obtained, which is advantageous for highly pulsatile
hormones such as corticosteroids. In addition, the licensing constraints
for noninvasive methods of sampling are less restrictive. However, such
techniques also have disadvantages. In particular, faecal, hair or
feather samples can indicate only average hormone levels over a
considerable, and possibly unknown, period. Compared with plasma levels,
noninvasive measures may result in a loss of sensitivity in any further
analyses examining the relations between hormone levels and other
variables (Shirtcliff et al. 2002). Furthermore, faecal samples in
particular may not be available from known individuals a known amount of
time after excretion, preventing reliable determination of individual
hormone levels. It is also worth considering that while noninvasive
sampling will not cause large increases in pulsatile 'stress' hormones
as caused by capture and restraint, some increase may occur merely as a
result of the presence of the sampler. In addition, there are a number
of validation issues concerning the quantification of steroids from
noninvasive samples which we outline below. Koren et al. (2002)
documented a protocol for the extraction of testosterone and cortisol
from hair obtained from the rock hyrax, Procavia capensis. They used
this technique to quantify the levels of hormones contained in plucked
hair samples, allowing hormone levels during the period of hair
production to be determined, noninvasively. They found that the levels
of testosterone extracted correlated positively with the dominance rank
of male hyraxes. Although such methods are highly desirable, it is
important to emphasize that all new methods of measuring levels of
hormone production using hormone extracted from organic substrates
should be appropriately validated, such that the limitations of the
technique can be defined. This requires: (1) that the assay is validated
for each new species and substrate and (2) that the extraction
efficiency is determined for the target hormone in the species and
substrate of interest. Although ready-made endocrine kits are provided
with some data on the assay validation, the validation is relevant only
for the species and substrate tested by the commercial supplier,
generally in a limited range of biological media. It is essential to
extend these validations for the species and substrate to which the kit
is being applied. For example, a methanol extract of hair may contain
substances that interfere with the assay procedure and thus would give
misleading results.
Carter, A.M.,
Enders, A.C., 2004. Comparative aspects of trophoblast development and
placentation. Reproductive Biology and Endocrinology 2.
Abstract: Based on the number of tissues separating maternal from fetal
blood, placentas are classified as epitheliochorial, endotheliochorial
or hemochorial. We review the occurrence of these placental types in the
various orders of eutherian mammals within the framework of the four
superorders identified by the techniques of molecular phylogenetics. The
superorder Afrotheria diversified in ancient Africa and its living
representatives include elephants, sea cows, hyraxes, aardvark, elephant
shrews and tenrecs. Xenarthra, comprising armadillos, anteaters and
sloths, diversified in South America. All placentas examined from
members of these two oldest superorders are either endotheliochorial or
hemochorial. The superorder Euarchontoglires includes two sister groups,
Glires and Euarchonta. The former comprises rodents and lagomorphs,
which typically have hemochorial placentas. The most primitive members
of Euarchonta, the tree shrews, have endotheliochorial placentation.
Flying lemurs and all higher primates have hemochorial placentas.
However, the lemurs and lorises are exceptional among primates in having
epitheliochorial placentation. Laurasiatheria, the last superorder to
arise, includes several orders with epitheliochorial placentation. These
comprise whales, camels, pigs, ruminants, horses and pangolins. In
contrast, nearly all carnivores have endotheliochorial placentation,
whilst bats have endotheliochorial or hemochorial placentas. Also
included in Laurasiatheria are a number of insectivores that have many
conserved morphological characters; none of these has epitheliochorial
placentation. Consideration of placental type in relation to the
findings of molecular phylogenetics suggests that the likely path of
evolution in Afrotheria was from endotheliochorial to hemochorial
placentation. This is also a likely scenario for Xenarthra and the bats.
We argue that a definitive epitheliochorial placenta is a secondary
specialization and that it evolved twice, once in the Laurasiatheria and
once in the lemurs and lorises.
Carter, A.M.,
Enders, A.C., Kunzle, H., Oduor-Okelo, D., Vogel, P., 2004. Placentation
in species of phylogenetic importance: The Afrotheria. Animal
Reproduction Science 82-83, 35-48.
Abstract: Afrotheria, one of four mammalian superorders, comprises
elephants, sea cows, hyraxes, aardvark, elephant shrews, tenrecs and
golden moles. Their placentas either form an equatorial band or are
discoid in shape. The interhemal region, separating fetal and maternal
blood, is endotheliochorial in elephants, aardvark and possibly the sea
cows, but hemochorial in the remaining orders. There is a secondary
epitheliochorial placenta in elephant shrews while a similar structure
in tenrecs erodes maternal tissues. Specialized hemophagous regions are
a striking characteristic of some of these placentas yet absent in
hyraxes, elephant shrews, and golden moles. It is possible that the
common ancestor of the Afrotheria had an endotheliochorial placenta.
Establishment of a hemochorial condition, as seen in rock hyraxes,
elephant shrews, tenrecs, and golden moles, would be a more recent
development. The elephant, manatee, and aardvark all have
circumferential placentas. Thus the formation of a discoid placenta with
a more or less extensive secondary placenta in elephant shrews and
tenrecs would also be a derived state.
Carter, A.M.,
Enders, A.C., Kunzle, H., Oduor-Okelo, D., Vogel, P., 2004. Placentation
in species of phylogenetic importance: the Afrotheria
705. Anim Reprod. Sci. 82-83, 35-48.
Abstract: Afrotheria, one of four mammalian superorders, comprises
elephants, sea cows, hyraxes, aardvark, elephant shrews, tenrecs and
golden moles. Their placentas either form an equatorial band or are
discoid in shape. The interhemal region, separating fetal and maternal
blood, is endotheliochorial in elephants, aardvark and possibly the sea
cows, but hemochorial in the remaining orders. There is a secondary
epitheliochorial placenta in elephant shrews while a similar structure
in tenrecs erodes maternal tissues. Specialized hemophagous regions are
a striking characteristic of some of these placentas yet absent in
hyraxes, elephant shrews, and golden moles. It is possible that the
common ancestor of the Afrotheria had an endotheliochorial placenta.
Establishment of a hemochorial condition, as seen in rock hyraxes,
elephant shrews, tenrecs, and golden moles, would be a more recent
development. The elephant, manatee, and aardvark all have
circumferential placentas. Thus the formation of a discoid placenta with
a more or less extensive secondary placenta in elephant shrews and
tenrecs would also be a derived state
Christiansen,
P., 2004. Body size in proboscideans, with notes on elephant metabolism.
Zoological Journal of the Linnean Society 140, 523-549.
Abstract: Mass estimates for a number of fossil proboscideans were
computed using regression analyses on appendicular bones to body mass,
for seven specimens of modern elephants, for which body masses had been
recorded prior to death. The marked differences in physical proportions
between extant Loxodonta and Elephas, implying substantial differences
in body mass at any given shoulder height, were not present in their
long bone parameters. Length and least circumferences proved to be the
best parameters for prediction of body mass. Some extinct proboscideans,
notably certain Mammuthus and Deinotherium, were much larger than extant
elephants. Both the basal and the field metabolic rates of extant
elephants are lower than predicted for a hypothetical mammal, in
accordance with their body size and subsistence on low-quality foods.
The feeding quantities often ascribed to extant wild elephants are
exaggerated, and would in fact have sufficed to nourish much larger
species.
Debruyne, R.,
2004. How many species of elephants in Africa? Appraisal of an apparent
controversy between molecular phylogenies. Cladistics-The International
Journal Of The Willi Hennig Society 20, 80-81.
Abstract: Note: this is an abstract from the 22nd Annual Meeting of the
Willi Hennig Society: The systematics of the African elephant, Loxodonta
africana, has become an issue since the publication of the first
mitochondrial sequence of a forest elephant (Barriel et al., 1999). The
then acknowledged subspecies, L. africana cyclotis (Matschie, 1900),
displayed a high level of divergence from the better-known savannah
elephant (L. africana africana). Further molecular investigations have
led authors to consider that forest and savnnah elephants consist of two
distinct species (Comstock et al., 2002; Roca et al., 2001). They rely
on an extensive sampling in Africa, though poorly documented for western
populations and areas where both forms of elephants co-occur. They
assayed the genetic diversity through nuclear markers, sequencing of
four nuclear genes and microsatellites that converge to the recognition
of two highly divergent clades they assume to match the systematic
division. Conversely, the analysis of 593 bp of mtDNA from a broader
sample produced results at odds (Eggert et al., 2002). The reciprocal
monophyly of the two lneages is not retrieved and African elephants
cluster in three main groups (western, central and south-eastern),
whatever their systematics. However, these results are weakly supported.
Here we address the validity of these inconsistent results by
reanalyzing available data and sequencing 1960 bp of mtDNA for 43
African elephants (morphologically determined as 26 savannah and 17
forest elephants). The sequenced fragment spans cytochrome b gene, Thr
and Pro tRNAs and Hyper-Variable Region 1 of the control region. Fifteen
sequences of Hyper-Variable Region 2, Phe tRNA and 12S rRNA were also
examined. Our phylogenetic analyses contradict both former studies.
Firstly, they show that two unambiguously supported clades do exist
within African elephants populations, Eggert's results (Eggert et al.
2002) being caused by an insufficient sampling of characters and a
misleading attitude in the choice of the evolution model of their
sequences. Secondly, this division into two main clades does not recover
savannah and forest elephants as monophyletic taxa, so that they are not
monophyletic species. While 21 sequences of savannah form a monophyletic
group, the 5 remnants are apart within remote clades of forest elephant
sequences. This conflicts with Roca et al.'s view (2001) that
hybridization between the two forms can be neglected. Nevertheless, we
confirm some former conclusions. Forest elephants display a stronger
inner-structuration than savannah elephants. We acknowledge that some
savannah elephants are mixed-up within forest elephant clades, but
reciprocally, no forest elephant specimen depicted a typical savannah
haplotype, so that the introgression of mitochondrial genome appears to
be unidirectional. We assume that this extant phylogeographic pattern is
the result of non-contemporary phenomena: (i) a prior isolation of
forest elephants on the one hand and of savannah elephants on the other,
leading to their molecular and morphological divergence, and (ii)
secondary recurrent events of local admixture between the two forms,
responsible for the geographic consistency of shared haplotypes between
L. a. cyclotis and L. a. africana. Therefore we conclude that a high
level of hybridization between the two forms of African elephant (with
long-term effects on the genetic integrity of populations) precludes the
recognition of two biological species. Address: Museum Natl Hist Nat,
Dept Hist Terre, CNRS, UMR 8569 8, F-75231 Paris, France
Debruyne, R.,
2004. [Contribution of molecular phylogeny and morphometrics to the
systematics of African elephants]
590. J. Soc. Biol. 198, 335-342.
Abstract: African elephants are conventionally classified as a single
species: Loxodonta africana (Blumenbach 1797). However, the discovery in
1900 of a smaller form of the African elephant, spread throughout the
equatorial belt of this land, has given rise to a debate over the
relevance of a second species of elephant in Africa. The twentieth
century has not provided any definite answer to this question. Actually,
recent molecular analyses have sustained this issue by advocating either
a division of forest elephants into a valid species, or their inclusion
as a subspecies of L. africana. Our work initiated at the National
Museum of Natural History of Paris provides new molecular
(mitochondrial) and morphological (and morphometrical) evidence making
it possible to propose a comprehensive phylogenetic hypothesis. It
appears that there is no conclusive argument to keep forest elephants (cyclotis
form) and savannah elephants (africana form) apart in two distinct
species. A high level of mitochondrial introgression between the two
forms, as well as a continuum in the morphology of the skulls of the two
morphotypes rather suggests that, despite an ancient division, these two
taxa freely interbreed wherever their ranges intersect. We thus adopt a
conservative systematic position in considering these two forms as two
subspecies, respectively: L. africana africana, the savannah elephant,
and L. africana cyclotis, the forest elephant. We finally discuss the
conservation topic in the light of this systematic framework
Elvin, M.,
2004. The Retreat of the Elephants: An Environmental History of China.
Yale University Press.
Abstract: Review from Nature 430, 505 - 506 (29 July 2004):
Pity the poor elephants! Over more than 4,000 years they were gradually
forced from living all over China to a few protected enclaves near the
border with Burma. The main reason was the destruction of their habitat
as humans cut down forests and introduced agriculture. Farmers found the
dwindling elephant herds a nuisance, as crops were trampled and
plundered. Others came to value elephants for military, transport and
ceremonial purposes: their ivory was prized and their trunks became a
gourmet delicacy. Elephant numbers shrank until they were little more
than a memory for most Chinese. Mark Elvin uses the decline of the
elephant as an allegory to illustrate the transformation of the Chinese
environment to the end of pre-industrial times. Some of the same story
can be seen in Africa today.
Elvin's book is not so much an environmental history of China as a
collection of its fragments. With copious quotations from Chinese
written sources of all kinds, he shows what happened in different places
and why. Even if we can see from archaeology that comparable events took
place elsewhere, only in China are there such written records, giving a
unique account of how it felt to live through them. It was not always a
pleasant or edifying process, and as usual the voices of those worst
affected will never be heard.
In broad terms, the transformation of the Chinese environment, which was
faster in some areas than others, had certain characteristics. First,
deforestation made way for agriculture. There was then a bonanza as
resources were exploited, species were lost and human numbers rose. This
triggered the growth of towns, cities and states with social
stratification, followed by increasing competition between them, with
war as the spur and the environment sometimes used as a weapon. Better
technology was mitigated by mismanagement of resources. Entrapment in
limited local circumstances
left people vulnerable to change. Finally, there was a greater risk of
social and economic collapse affecting society as a whole. Elvin shows
the differences clearly in three areas: Jiaxing to the south of the
Yangzi river; Guizhou in the south, where the Han people gradually
displaced the indigenous Miao; and Zunhua in the mountainous northeast.
Everywhere, control of water was essential. 'Hydraulic despotism' may
tell only part of the story, but communities and even states grew partly
out of the need to manage this precious and sometimes capricious
resource. The struggle to run irrigation systems, limit marine
incursions, maintain banks and walls, undertake dredging, cope with
floods and storms, and adapt to ever-changing weather patterns is as
difficult today as it ever was. With huge populations dependent on
particular systems, any change can become increasingly difficult to cope
with.
The complexity of Chinese attempts to manage human effects on the
environment is remarkable. Even more special are the Chinese beliefs and
attitudes towards the environment that have existed over the millennia.
Generalizations are bound to be misleading but, in general terms, the
Chinese were driven, in Elvin's words, by a desire for rational mastery
of the world. They had little hesitation in uprooting forests,
redirecting and polluting rivers, destroying natural landscapes and
giving political and military needs absolute priority. They had
remarkable powers of organization, and ran projects far beyond European
capacities at the time. But in doing so, the Chinese paid scant regard
to the environment and unwittingly created many long-term problems.
On the other hand, the Chinese had a particularly sensitive respect for
nature and natural beauty in all its forms. Even as forests were
destroyed, individual trees were singled out for admiration. Heaven and
Earth were closely linked, and the line between the natural and the
supernatural was blurred. There was a confluence of matter leading to
energy, and energy leading to life, each a product of Bright Force and
Dark Force. Dragons and spirits were sometimes seen above the surface in
thunder and lightning, and sometimes below it in earthquakes. They
formed part of a living world that
sustained and punished humans. They even related the behaviour of the
weather to human activity, so there was morality in meteorology.
In such a world, it was crucial to divine what the invisible forces felt
or did. This could involve sacrificing animals or humans, or burning
cracks in the shoulder blades of mammals or the undershells of turtles.
In Shang times, such practices had political significance as the ruler
was the intermediary between the visible and the invisible world. This
was also true in other epochs when the apparatus of authority was given
almost divine attributes.
It is as difficult for us to enter into this mental cosmology as into
that of our own ancestors in pre-scientific times. Elvin shows that
searching for observable and verifiable facts about the world, and
putting them to use in programmes of thought, was almost entirely alien
to the Chinese. As a result, the shock of change was more abrupt in
China than it was in Europe, where the scientific revolution began
earlier. Traces of the old thinking may have survived Mao Zedong and
persist in fundamental ways today.
The Retreat of the Elephants is not an easy book to read. Some of the
quotations seem scarcely relevant, and the whole text could have been
usefully pruned. At the end there is an unilluminating venture into
equations, as if sustainability could be reduced to an algorithm. Yet
taken as a whole, the book is a fascinating, scholarly miscellany of
stories, poetry and ideas from the history of the longest continuous
civilization on Earth. The relationship of that civilization with its
fragile and often tortured surroundings contains lessons for others -
particularly at a time when industrial society in China, as elsewhere,
is pressing harder than ever on the environment. This will be a source
book, elephants and all, for generations to come.
Enders, A.C.,
Carter, A.M., 2004. What can comparative studies of placental structure
tell us?--A review
739. Placenta 25 Suppl A , S3-S9.
Abstract: The diversity of placental structures in Eutherian mammals is
such that drawing generalizations from the definitive forms is
problematic. There are always areas of reduced interhaemal distance
whether the placenta is epitheliochorial, synepitheliochorial,
endotheliochorial or haemochorial. However, the thinning may be achieved
by different means. The presence of a haemophagous area as an iron
transport facilitator is generally associated with endotheliochorial
placentae but is also found in sheep and goats (synepitheliochorial) and
in tenrecs and hyaenas (haemochorial). Although similar chorioallantoic
placentae are found within families, structure begins to diverge at the
ordinal level and there is little correlation at the supraordinal level
of phylogeny. Differences in formation and function of the yolk sac
provide additional variation. There would appear to be considerable
adaptive pressure for development or retention of the haemochorial type
of chorioallantoic placenta. This type of placenta has several possible
drawbacks including more ready passage of fetal cells to the maternal
organism and, should the haemochorial condition be achieved early,
oxidative stress. At any rate no animal larger than the human and
gorilla has this type of placenta. The endotheliochorial condition is
found in animals as large as the bears, manatee and elephants. In
addition to the ungulates, the epitheliochorial condition is present in
the largest animals with the longest gestation periods, the whales.
Considering the length of time since the early stages of mammalian
evolution, it is probable that few unmodified structural features are
present in any currently surviving mammal. Nevertheless, more complete
studies of divergent types of mammalian placenta should help our
understanding of mammalian interrelationships as well as placental
function
Greenwood,
A.D., Englbrecht, C.C., MacPhee, R.D., 2004. Characterization of an
endogenous retrovirus class in elephants and their relatives
667. BMC. Evol. Biol. 4, 38.
Abstract: BACKGROUND: Endogenous retrovirus-like elements (ERV-Ls,
primed with tRNA leucine) are a diverse group of reiterated sequences
related to foamy viruses and widely distributed among mammals. As shown
in previous investigations, in many primates and rodents this class of
elements has remained transpositionally active, as reflected by
increased copy number and high sequence diversity within and among taxa.
RESULTS: Here we examine whether proviral-like sequences may be suitable
molecular probes for investigating the phylogeny of groups known to have
high element diversity. As a test we characterized ERV-Ls occurring in a
sample of extant members of superorder Uranotheria (Asian and African
elephants, manatees, and hyraxes). The ERV-L complement in this group is
even more diverse than previously suspected, and there is sequence
evidence for active expansion, particularly in elephantids. Many of the
elements characterized have protein coding potential suggestive of
activity. CONCLUSIONS: In general, the evidence supports the hypothesis
that the complement had a single origin within basal Uranotheria
Hoffmann, J.N.,
Montag, A.G., Dominy, N.J., 2004. Meissner corpuscles and somatosensory
acuity: the prehensile appendages of primates and elephants
669. Anat. Rec. A Discov. Mol. Cell Evol. Biol. 281, 1138-1147.
Abstract: Meissner corpuscles (MCs) are specialized mechanoreceptors
located exclusively in the papillae of glabrous skin. They are confined
largely to cutaneous pads of the extremities and respond to transient,
phasic, or vibratory stimuli. Though absent in most eutherian taxa, MCs
are reported in all primates studied, being most developed in modern
humans. The location of MCs between the internal ridges of the epidermis
indicates they are well situated to detect friction or deformation at
the external surface. Accordingly, MCs are hypothesized to provide
primates generally with an enhanced tactile perception. However, the
selective pressures favoring greater somatosensory acuity in primates
are seldom considered. Interestingly, primate digital dexterity varies
greatly. In general, dexterity improves with the extent to which
foraging requires food manipulation or textural evaluation. This
observation implies that MC density could vary accordingly. Here we
report on the density of MCs in five anthropoid taxa selected to
represent diverse dietary regimes. Results show that greater MC density
correlates with the extent to which primates are frugivorous; however,
locomotor and/or phylogenetic effects cannot be discounted
Repin, V.E.,
Taranov, O.S., Ryabchikova, Tikhonov, A.N., Pugachev, V.G., 2004.
Sebaceous glands of the woolly mammoth, Mammothus primigenius Blum:
histological evidence
651. Dokl. Biol. Sci. 398, 382-384.
Sarma, K.K.,
2004. Extraction of decayed tusk in elephants. Indian Veterinary Journal
81, 812-814.
Abstract: Case history of dental pulp decay in eight male Asian
elephants is discussed. Causes of injury and infection, pathological
process and clinical signs are elaborated. Treatment of the cases by
extraction of the decayed tusks, anaesthetic management, operative
procedure, post operative care and the outcome of treatment has been
discussed.
Shimoyama,
M., Morimoto, S., Ozaki, Y., 2004. Non-destructive analysis of the two
subspecies of African elephants, mammoth, hippopotamus, and sperm whale
ivories by visible and short-wave near infrared spectroscopy and
chemometrics
721. Analyst 129, 559-563.
Abstract: Visible (VIS) and short-wave near infrared (SW-NIR)
spectroscopy was used for non-destructive analysis of ivories. VIS-SW-NIR
(500-1000 nm) spectra were measured in situ for five kinds of ivories,
that is two subspecies of African elephants, mammoth, hippopotamus, and
sperm whale. Chemometrics analyses were carried out for the spectral
data from 500 to 1000 nm region. The five kinds of ivories were clearly
discriminated from each other on the scores plot of two principal
components (PCs) obtained by principal component analysis (PCA). It was
noteworthy that the ivories of the two subspecies of African elephants
were discriminated by the scores of PC 1. The loadings plot for PC 1
showed that the discrimination relies on the intensity changes in bands
due to collagenous proteins and water interacting with proteins. It was
found that the scores plot of PC 2 is useful to distinguish between the
ivories of the two subspecies of African elephants and the other
ivories. We also developed a calibration model that predicted the
specific gravity of five kinds of ivories from their VIS-SW-NIR spectral
data using partial least squares (PLS)-1 regression. The correlation
coefficient and root mean square error of cross validation (RMSECV) of
this model were 0.960 and 0.037, respectively
Stahl, A.B.,
Stahl, P.W., 2004. Ivory production & consumption in Ghana in the early
second millennium AD. Antiquity 78, 86-101.
Abstract: In the eighteenth to nineteenth century West Africa was the
scene of the infamous Atlantic trade in ivory and slaves. The authors'
researches show a different situation in the fourteenth to seventeenth
centuries, when the people of Ghana were engaged in the indigenous
procurement, manufacture and trade in ivory with neighbours across the
Sahara. Address: Stahl AB, SUNY Binghamton, Dept Anthropol, Binghamton,
NY 13902 USA.
Stringfield,
C.E., Oh, P., Granich, R., Scott, J., Sun, B., Joseph, M., Flood, J.,
Sedgwick, C.J. Epidemiologic investigation of a Mycobacterium
tuberculosis infection of multiple animal species in a metropolitan
zoo. 2004 PROCEEDINGS AAZV, AAWV, WDA JOINT CONFERENCE. 46-48.
2004.
Ref Type: Conference Proceeding
Abstract: From 1997 to 2000, six cases of Mycobacterium tuberculosis
(TB) infection were diagnosed in three species of animals at, or
recently originating from, the Los Angeles Zoo. Restriction fragment
length polymorphism (RFLP) analysis showed that five of six animal
isolates shared an identical IS6110 pattern, with the sixth differing
only by one additional band. A multiinstitutional epidemiologic
investigation was conducted to identify and interrupt possible
transmission among the animal cases, and to screen personnel for active
TB infection and TB skin-test conversion.
Animal Cases
In April and October of 1994, Asian elephant (Elephas maximus)
#1 and Asian elephant #2 arrived at the Los Angeles Zoo from a private
elephant facility where they had lived together. They were housed
together at the zoo until November of 1996 when elephant #2 was returned
to the facility for several months before transfer to another zoo. In
the spring of 1997, Elephant #1 (30 yr old) died of salmonellosis, with
M. tuberculosis found in granulomatous lymph node lesions from
the thoracic and abdominal cavities, and Elephant #2 (30 yr old) was
found to have a positive trunk wash culture for M. tuberculosis.
In July of 1998, one of a closed herd of three Rocky Mountain goats (Oreamnos
americanus) consisting of a sire and two offspring, died of
pulmonary M. tuberculosis at 6 yr of age. The goat's asymptomatic
herdmates were screened and had negative chest radiographs and tracheal
wash cultures, but one of the two goats was positive on tuberculin
skin-test. In October of 1998, a clinically normal Black rhinocerus (Diceros
bicornis) was diagnosed with Mycobacerium tuberculosis after
a positive skin test and nasal wash culture. In the winter of 1998, the
two remaining goats were evaluated again with negative chest radiographs
and tracheal wash cultures. However, 1 yr later, both were humanely
euthanatized at 8 and 12 yr of age due to clinical evidence of
tuberculosis on chest radiographs (both animals), and active clinical
signs in one (neither were able to be orally treated). In January of
2001, a rhino was humanely euthanatized after a protracted illness that
was nonresponsive to aggressive treatment. The rhino was found to have
severe multifocal hemosiderosis and atypical mycobacterial infection in
her lungs, with no M. tuberculosis cultured. This animal had
been treated with oral Isoniazid and Rifampin for 1 yr, cultured
routinely, and was never culture positive again.
Epidemiologic Investigation
Investigators examined medical and location histories of the
affected animals, animal handling practices, health-care procedures, and
performed an infection control assessment of the animal compounds and
health-care facilities (including measuring air flow in the compounds by
smoke testing). We conducted a review of zoo employee medical records
for evidence of TB symptoms, tuberculin skin-test results, and chest
radiograph information. A list of current and former employees was
cross-matched with reported TB cases in the California state registry
from 1985 to 2000. As part of the annual occupational health screening
in June of 2000, zoo employees underwent questioning regarding TB
symptoms, received tuberculin skin tests, and completed a questionnaire
on medical history, job type, and history of contact with the infected
animals.
Epidemiologic Findings
No common cross-species contact outside the animal compounds and no
contact with an infectious human were found. The distance at which the
public was kept from the animals and the distance of the compounds from
each other (the elephant compound was 27 meters from the rhino compound
and the goat compound was 90 m from both) suggests that direct
transmission was unlikely. No active TB cases in humans were found, and
no matches were found in the database of reporte d cases. The RFLP
analysis of this strain of M. tuberculosis matched that of three
elephants with which #1 and #2 were housed at a private elephant
facility from September of 1993-February of 1994.1 We hypothesize that
elephants #1 and #2 were infected at the private facility and were
shipped with latent M. tuberculosis infection in 1994, subsequently
infecting the black rhino and Mountain goats at the Los Angeles Zoo.
Of interest, animal caretaking and animal contact were not associated
with a positive tuberculin skin-test, while groundskeepers were found to
have an increased risk of tuberculin skin-test conversion compared with
other job categories. Employees attending the elephant necropsy and
employees who trained elephants were more likely to have tuberculin
skin-test conversion than those who did not.
Conclusion
This is the first documented human and veterinary epidemiologic
investigation of Mycobacterium tuberculosis affecting multiple
species in a zoo. 2 No evidence of transmission from humans
to animals or active infections in humans were found. Genotyping
evidence strongly suggests transmission from one species to another,
although no evidence of transmission was discovered. Human tuberculin
skin-test conversions associated with the elephants were most likely due
to lack of respiratory protection for these employees when the risk of
TB infection was not known. The finding that groundskeepers and not
animal handlers were associated with a higher risk of tuberculin
skin-test conversion was surprising, and we hypothesized that this may
have to do with groundskeepers as a group being more likely to have
been born outside of the United States.
Control measures to eliminate the spread of disease to people and
animals were undertaken immediately and throughout this outbreak, and no
further cases of M. tuberculosis have been diagnosed at the zoo
in the past 3 yr despite ongoing surveillance. Four elephants and three
rhinos that had direct contact with the infected animals remain TB
negative by trunk and nasal wash culture methods as outlined by the USDA
for elephant TB surveillance. Methods of indirect transmission in
mammalian zoo species and causes of variability in infection and
morbidity within and among species warrant further investigation.
Ongoing vigilance, occupational health programs and infection control
measures in potentially exposed animals are recommended to prevent
ongoing transmission of M. tuberculosis in zoo settings.
Acknowledgments
The authors thank the Animal Care and Animal Health staff of the Los
Angeles Zoo who cared so well for these animals, and the veterinarians
(including consulting pathologists), technicians, and medical records
staff who collected, analyzed, and organized the clinical data. We could
not have performed this evaluation without Sue Thisdell, Safety Officer
at the Los Angeles Zoo; Jothan Staley and Donna Workman-Malcom of the
City of Los Angeles Occupational Health Services Division; Lee
Borenstein, Elenor Lehnkering, Patrick Ryan, Jeanne Soukup, and Annette
Nita of the Los Angeles County Department of Health Services; and Diana
Whipple for her RFLP expertise.
LITERATURE CITED
1. Mikota, S.K., L. Peddie, J. Peddie, R. Isaza, F. Dunker, G. West,
W. Lindsay, R.S.Larsen, M. D. Salman, D. Chatterjee, J. Payeur, D.
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Suarez, R.K.,
Darveau, C.A., Childress, J.J., 2004. Metabolic scaling: a many-splendoured
thing
656. Comp Biochem. Physiol B Biochem. Mol. Biol. 139, 531-541.
Abstract: Animals at rest and during exercise display rates of aerobic
metabolism, VO2, that represent mainly the sum of mitochondrial
respiration rates in various organs. The relative contributions of these
organs change with physiological state such that internal organs such as
liver, kidney and brain account for most of the whole-body VO2 at rest,
while locomotory muscles account for >90% of the maximum rate, VO2max,
during maximal aerobic exercise. Mechanisms that regulate VO2 are
complex and the relative importance of each step in a series, estimated
by metabolic control analysis, depends upon the level of biological
organization under consideration as well as physiological state. Despite
this complexity, prominent single-cause models propose that metabolic
rates are supply-limited and that the scaling of supply systems provides
a sufficient explanation for the allometric scaling of metabolism. We
argue that some assumptions, as well as current interpretations of the
meaning (or consequences) of these constraints are flawed, i.e.,
elephants do not have lower mass-specific basal or maximal rates of
aerobic metabolism because their mitochondria are more supply-limited
than those of shrews. Animals do not violate the laws of physics, and
the allometric scaling of supply systems would be expected, to some
extent, to be matched by capacities for (and rates of) energy
expenditure. But life is not so simple. Animals are so diverse that to
do justice to metabolic scaling, it is also necessary to consider the
scaling of energy expenditure. It is by doing so that models of
metabolic scaling can be consistent with current paradigms in metabolic
regulation and accommodate the range of inter- and intraspecific
exponents found in nature. The "allometric cascade," a first attempt at
such an accounting, was a source of great satisfaction to Peter
Hochachka. It was the last door that he helped open to comparative
physiologists before he said goodbye
Taranov, O.,
Ryabchikova, E., Tikhonov, A., Pugachev, V., Repin, V., 2004. Sebaceous
glands of woolly mammoth (the histological evidence). Proceedings of the
Russian Academy of Sciences, ser. biol. , 398, 139-141.
Tefera, M.,
2004. Recent evidence of animal exploitation in the Axumite epoch,
1st-5th centuries AD
743. Trop. Anim Health Prod. 36, 105-116.
Abstract: This study reports evidence of animal exploitation during the
Axumite era based on a survey of architectural features, rock art and
artefacts recovered from the archaeological site at Axum, northern
Ethiopia. Animals and agricultural tools were identified from materials
not previously examined. Pottery, rock art and animal remains revealed a
range of zoological species. Agricultural implements and sacrificial
vessels also provided indirect evidence of animal exploitation. It is
concluded that, in addition to plough-based agriculture, the hunting of
large wild animals, such as elephants and lions, and the exploitation of
domestic cattle, small ruminants and poultry were part of the Axumite
subsistence regime. Although it is difficult to reconstruct an overall
subsistence pattern based on this study alone, the physical and
biological evidence suggests that the Axumites practised combined
cultivation and animal herding. Further investigation is required to
study the types and breeds of animals and their distribution in time and
space
Clauss, M.,
Frey, R., Kiefer, B., Lechner-Doll, M., Loehlein, W., Polster, C.,
Rossner, G.E., Streich, W.J., 2003. The maximum attainable body size of
herbivorous mammals: morphophysiological constraints on foregut, and
adaptations of hindgut fermenters. Oecologia 136, 14-27.
Abstract: An oft-cited nutritional advantage of large body size is that
larger animals have lower relative energy requirements and that, due to
their increased gastrointestinal tract (GIT) capacity, they achieve
longer ingesta passage rates, which allows them to use forage of lower
quality. However, the fermentation of plant material cannot be optimized
endlessly; there is a time when plant fibre is totally fermented, and
another when energy losses due to methanogenic bacteria become punitive.
Therefore, very large herbivores would need to evolve adaptations for a
comparative acceleration of ingesta passage. To our knowledge, this
phenomenon has not been emphasized in the literature to date. We propose
that, among the extant herbivores, elephants, with their comparatively
fast passage rate and low digestibility coefficients, are indicators of
a trend that allowed even larger hindgut fermenting mammals to exist.
The limited existing anatomical data on large hindgut fermenters
suggests that both a relative shortening of the GIT, an increase in GIT
diameter, and a reduced caecum might contribute to relatively faster
ingesta passage; however, more anatomical data is needed to verify these
hypotheses. The digestive physiology of large foregut fermenters
presents a unique problem: ruminant-and nonruminant-forestomachs were
designed to delay ingesta passage, and they limit food intake as a side
effect. Therefore, with increasing body size and increasing absolute
energy requirements, their relative capacity has to increase in order to
compensate for this intake limitation. It seems that the foregut
fermenting ungulates did not evolve species in which the intake-limiting
effect of the foregut could be reduced, e.g. by special bypass
structures, and hence this digestive model imposed an intrinsic body
size limit. This limit will be lower the more the natural diet enhances
the ingesta retention and hence the intake-limiting effect. Therefore,
due to the mechanical characteristics of grass, grazing ruminants cannot
become as big as the largest browsing ruminant. Ruminants are not absent
from the very large body size classes because their digestive physiology
offers no particular advantage, but because their digestive physiology
itself intrinsically imposes a body size limit. We suggest that the
decreasing ability for colonic water absorption in large grazing
ruminants and the largest extant foregut fermenter, the hippopotamus,
are an indication of this limit, and are the outcome of the competition
of organs for the available space within the abdominal cavity. Our
hypotheses are supported by the fossil record on extinct ruminant/tylopod
species which did not, with the possible exception of the Sivatheriinae,
surpass extant species in maximum body size. In contrast to foregut
fermentation, the GIT design of hindgut fermenters allows adaptations
for relative passage acceleration, which explains why very large extinct
mammalian herbivores are thought to have been hindgut fermenters.
Institute of Animal Physiology, Physiological Chemistry and Animal
Nutrition, Ludwig-Maximilians-University, Veterinaerstrasse 13, 80539,
Munich, Germany. clauss@tiph.vetmed.uni-muenchen.de
Cristoffer,
C., Peres, C.A., 2003. Elephants versus butterflies: the ecological role
of large herbivores in the evolutionary history of two tropical worlds.
Journal of Biogeography 9, 1357-1380.
Abstract: Aim Large herbivores have important effects upon Paleotropical
ecosystems, but attain much lower biomass densities in the Neotropics.
We assess how this difference in herbivore activity has generated
different ecological and evolutionary trajectories in the New and Old
World tropics. We also propose an explanation for how the greater
biomass density in the Old World came about. Location Data were compiled
primarily from moist tropical forests, although more of the relevant
information to address most of our hypotheses was available from the
mainland areas of Africa, Asia, and South America than elsewhere.
Methods We gleaned data from published information and personal
communication. We compared body masses and a variety of other types of
information for the New- and Old-World tropics. We proposed that
interhemispheric differences exist in a variety of processes, including
herbivory, frugivory, and flower visitation. We erected hypotheses and
evaluated them qualitatively, and, when information was available,
tested them using simple ratios of species in various taxonomic and
trophic categories. To make the comparisons more meaningful, we
specified appropriate data selection criteria. Results A general pattern
of differences emerges from this review. Compared with Neotropical
forests, the much greater biomass densities of large herbivores in
Paleotropical forests are associated with a lesser diversity of small
herbivores, different hunting methods used by indigenous humans, larger
arboreal vertebrates, larger fruits, different patterns of fruit and
flower dispersion in space and time, a lesser abundance of most types of
reproductive plant parts, and other features. The existence of a
species-rich fauna of large herbivores in the pre-Holocene Neotropical
rain forest was not supported. Main conclusions: The potential for large
herbivores to cause functional differences between the New and Old World
tropical forests has been virtually unexplored, despite the well-known
importance of large herbivores in the Old World tropics. The evaluations
of our hypotheses suggest that the abundance of large herbivores in the
Old World tropics has launched it onto a different evolutionary
trajectory than that of the NewWorld tropics. The relevant evidence,
although scanty, suggests that the interhemispheric ecological
differences are not an artefact of recent megafaunal extinctions in the
New World. Recent human activities have, however, reduced population
sizes of large wild herbivores in the Old World, and increased
population sizes of livestock. This has likely created a rather
homogeneous, anthropogenic selection pressure that tends to erase the
evolutionary differences between the two tropical worlds.
Debruyne, R.,
Barriel, V., Tassy, P., 2003. Mitochondrial cytochrome b of the Lyakhov
mammoth (Proboscidea, Mammalia): new data and phylogenetic analyses of
Elephantidae. Mol Phylogenet Evol 26, 421-434.
Abstract: The phylogenetic relationships between recent Elephantidae (Proboscidea,
Mammalia), that is to say extant elephants (Asian and African) and
extinct woolly mammoth, have remained unclear to date. The prevailing
morphological scheme (mammoth grouped with Asian elephant) is either
supported or questioned by the molecular results. Recently, the
monophyly of woolly mammoths on mitochondrial grounds has been
demonstrated (Thomas, et al., 2000), but it conflicts with previous
studies (Barriel et al., 1999; Derenko et al., 1997). Here, we report
the partial sequencing of two mitochondrial genes: 128 bp of 12S rDNA
and 561 bp of cytochrome b for the Lyakhov mammoth, a 49,000-year-old
Siberian individual. We use the most comprehensive sample of mammoth (11
sequences) to determine whether the sequences achieved by former studies
were congruent or not. The monophyly of a major subset of mammoths
sequences (including ours) is recovered. Such a result is assumed to be
a good criterion for ascertaining the origin of ancient DNA. Our
sequence is incongruent with that of Yang et al. (1996), though obtained
for the same individual. As far as the latter sequence is concerned, a
contamination by non-identified exogenous DNA is suspected. The
robustness and reliability of the sister group relation between
Mammuthus primigenius and Loxodonta africana are examined:
down-weighting saturated substitutions has no impact on the topology;
analyzing data partitions proves that the support of this clade can be
assigned to the most conservative phylogenetic signal; insufficient
taxonomic and/or characters sampling contributed to former discordant
conclusions. We therefore assume the monophyly of "real mammoth
sequences" and the (Mammuthus, Loxodonta) clade. Laboratoire de
Paleontologie, CNRS UMR 8569, Museum National d'Histoire Naturelle, 8
Rue Buffon, F-75005 Paris, France. debruyne@mnhn.fr
Debruyne, R.,
Van Holt, A., Barriel, V., Tassy, P., 2003. Status of the so-called
African pygmy elephant (Loxodonta pumilio (NOACK 1906)): phylogeny of
cytochrome b and mitochondrial control region sequences. C R Biol 326,
687-697.
Abstract: Among the African elephants, it has been unanimously
acknowledged that the forest elephants (cyclotis form) are peculiar, so
that they have been elevated to the specific rank. The development of
molecular analyses of extant Loxodonta has only focused on two forms
yet: the savannah form (africana) and the forest form (cyclotis),
disregarding the so-called pygmy elephants (pumilio or fransseni) the
systematic status of which has been debated since their discovery.
Therefore, we have sampled nine dwarfed-labelled specimens in collection
and eight specimens of typical forest elephants that we compared to
three savannah elephants and two Asian elephants. Because of the
degraded nature of the nuclear DNA content in bone samples of old
specimens, we assayed mitochondrial markers; 1961 bp of the
mitochondrial genome were sequenced (over a continuous range spanning
the cytochrome b gene, tRNA Thr, tRNA Pro, hypervariable region 1 and
central conserved region of the control region). Pumilio and cyclotis
are not sister-taxa: the phylogenetic analyses rather account for the
inclusion of the so-called pygmy elephants within a monophyletic group
of forest elephants sensu lato. The internal structure of this clade
reveals to depend on isolation and remoteness between populations,
characteristics that may have been extensively influenced by climatic
variations during the Quaternary period. We conclude that the specific
taxon Loxodonta pumilio (or Loxodonta fransseni) should be abandoned. FR
1541 CNRS, Service de systematique moleculaire, Museum national
d'histoire naturelle, 43, rue Cuvier, 75005 Paris, France. debruyne@mnhn.fr
Dubois, J.Y.,
Ursing, B.M., Kolkman, J.A., Beintema, J.J., 2003. Molecular evolution
of mammalian ribonucleases 1. Mol Phylogenet Evol. 27, 453-463.
Abstract: There have been many studies on the chemistry of mammalian
pancreatic ribonucleases (ribonucleases 1), but the functional biology
of this family of homologous proteins is still largely unknown. Many
studies have been performed on the molecular evolution and properties of
this enzyme from species belonging to a large number of mammalian taxa,
including paralogous gene products resulting from recent gene
duplications. Novel ribonuclease 1 sequences were determined for three
rodent species (gundi, brush-tailed porcupine, and squirrel), rabbit, a
fruit bat, elephant, and aardvark, and the new sequences were used for
deriving most parsimonious networks of ribonucleases from different
mammalian orders, including earlier determined nucleotide sequences and
also a larger set of protein sequences. Weak support for interordinal
relationships were obtained, except for an Afrotheria clade containing
elephant and aardvark. Results of current analyses and also those
obtained 20 years ago on amino acid sequences confirm conclusions
derived recently from larger data sets of other molecules. Several
examples of recent gene duplications in ribonucleases 1 are discussed,
with respect to illustrate the concepts of orthology and paralogy.
Previously evidence was presented for extensive parallelism between
sequence regions with attached carbohydrate (about one quarter of the
molecule) of unrelated species with cecal digestion (pig and guinea
pig). These features are also present in the sequences of elephant and
fruit bat, species with cecal digestion, but with a very low
ribonuclease content in their pancreas. Department of Biochemistry,
University of Groningen, Groningen, The Netherlands. dubois@farm.rug.nl
Eggert, L.S.,
Eggert, J.A., Woodruff, D.S., 2003. Estimating population sizes for
elusive animals: the forest elephants of Kakum National Park, Ghana. Mol
Ecol 12, 1389-1402.
Abstract: African forest elephants are difficult to observe in the dense
vegetation, and previous studies have relied upon indirect methods to
estimate population sizes. Using multilocus genotyping of noninvasively
collected samples, we performed a genetic survey of the forest elephant
population at Kakum National Park, Ghana. We estimated population size,
sex ratio and genetic variability from our data, then combined this
information with field observations to divide the population into age
groups. Our population size estimate was very close to that obtained
using dung counts, the most commonly used indirect method of estimating
the population sizes of forest elephant populations. As their habitat is
fragmented by expanding human populations, management will be
increasingly important to the persistence of forest elephant
populations. The data that can be obtained from noninvasively collected
samples will help managers plan for the conservation of this keystone
species. Ecology, Behavior and Evolution Section, Division of Biological
Sciences, University of California, San Diego 92093-0116, USA.
lori_eggert@hotmail.com
Fernando, P.,
Vidya, T.N., Payne, J., Stuewe, M., Davison, G., Alfred, R.J., Andau,
P., Bosi, E., Kilbourn, A., Melnick, D.J., 2003. DNA analysis indicates
that Asian elephants are native to Borneo and are therefore a hgh
priority for conservation. PLoS Biol. 1, E6 (Epub 2003 Aug 18).
Abstract: The origin of Borneo's elephants is controversial. Two
competing hypotheses argue that they are either indigenous, tracing back
to the Pleistocene, or were introduced, descending from elephants
imported in the 16th-18th centuries. Taxonomically, they have either
been classified as a unique subspecies or placed under the Indian or
Sumatran subspecies. If shown to be a unique indigenous population, this
would extend the natural species range of the Asian elephant by 1300 km,
and therefore Borneo elephants would have much greater conservation
importance than if they were a feral population. We compared DNA of
Borneo elephants to that of elephants from across the range of the Asian
elephant, using a fragment of mitochondrial DNA, including part of the
hypervariable d-loop, and five autosomal microsatellite loci. We find
that Borneo's elephants are genetically distinct, with molecular
divergence indicative of a Pleistocene colonisation of Borneo and
subsequent isolation. We reject the hypothesis that Borneo's elephants
were introduced. The genetic divergence of Borneo elephants warrants
their recognition as a separate evolutionary significant unit. Thus,
interbreeding Borneo elephants with those from other populations would
be contraindicated in ex situ conservation, and their genetic
distinctiveness makes them one of the highest priority populations for
Asian elephant conservation. Center for Environmental Research and
Conservation, Columbia University, New York, New York, United States of
America. pf133@columbia.edu
Fronicke, L.,
Wienberg, J., Stone, G., Adams, L., Stanyon, R., 2003. Towards the
delineation of the ancestral eutherian genome organization: comparative
genome maps of human and the African elephant (Loxodonta africana)
generated by chromosome painting. Proc R Soc Lond B Biol Sci. 270,
1331-1340.
Abstract: This study presents a whole-genome comparison of human and a
representative of the Afrotherian clade, the African elephant, generated
by reciprocal Zoo-FISH. An analysis of Afrotheria genomes is of special
interest, because recent DNA sequence comparisons identify them as the
oldest placental mammalian clade. Complete sets of whole-chromosome
specific painting probes for the African elephant and human were
constructed by degenerate oligonucleotide-primed PCR amplification of
flow-sorted chromosomes. Comparative genome maps are presented based on
their hybridization patterns. These maps show that the elephant has a
moderately rearranged chromosome complement when compared to humans. The
human paint probes identified 53 evolutionary conserved segments on the
27 autosomal elephant chromosomes and the X chromosome. Reciprocal
experiments with elephant probes delineated 68 conserved segments in the
human genome. The comparison with a recent aardvark and elephant
Zoo-FISH study delineates new chromosomal traits which link the two
Afrotherian species phylogenetically. In the absence of any
morphological evidence the chromosome painting data offer the first
non-DNA sequence support for an Afrotherian clade. The comparative human
and elephant genome maps provide new insights into the karyotype
organization of the proto-afrotherian, the ancestor of extant placental
mammals, which most probably consisted of 2n=46 chromosomes. Erratum
in: Proc R Soc Lond B Biol Sci. 2003 Dec 22;270(1533):2639. Comparative
Molecular Cytogenetics Section, National Cancer Institute-Genetics
Branch, National Cancer Institute-Frederick, Nationa Institutes of
Health, Building 560, Room 11-75, Frederick, MD 21702-1201, USA.
froenickel@gmx.net
Martin, F.,
Niemitz, C., 2003. "Right-trunkers" and "left-trunkers": side
preferences of trunk movements in wild Asian elephants (Elephas
maximus). J. Comp Psychol. 117, 371-379.
Abstract: In this article, the side preferences of feeding-related trunk
movements of free-ranging Asian elephants (Elephas maximus) were
investigated for the first time. It is hypothesized that a functional
asymmetry of the trunk is necessary to perform skillful feeding
movements more efficiently. This might be connected with a corresponding
hemispheric specialization. Video recordings of 41 wild elephants
provided frequencies and durations of the following trunk-movement
categories: object contact, retrieval, and reaching. In each category,
individual side preferences were found. The strength of side preferences
varied between the trunk-movement categories and the sexes. Mean
durations of retrieval and reaching correlated negatively with the
strength of side biases. Comparing the side preferences in the unpaired
trunk with analogous phenomena in other unpaired grasping organs and in
primate handedness. the authors discuss possible explanations for the
evolution of asymmetries in unpaired grasping organs.
Meredith, M.,
2003. Biography of an Endangered Species in Africa. PublicAffairs.
Abstract: Review from Publishers Weekly: In this solid introduction to
the world of elephants, Meredith covers all the major topics including
biology, social behavior, recent scientific discoveries, ancient
elephantology, the devastating ivory trade, the truth about elephant
graveyards and the insistent threat of extinction. Meredith
demonstrates that human involvement in elephantine affairs has been
disastrous to the pachyderm: the quest for ivory had caused the
extinction of all Syrian herds by 500 B.C.; many ancient cultures took
elephants to war; and Romans used the animals in their blood sports.
Much of the book follows the history of the European exploitation of
Africa's three treasures: gold, slaves and ivory. The quantities of
murdered elephants and descriptions of killing methodologies are deeply
affecting. Once Meredith's history reaches modern times, the shock of
population counts is astounding in comparison with the numbers of
elephants that roamed free in the past. Aristotle's treatise on the
animals' anatomy, behavior, diet and reproduction was the beginning of
a long line of nterest, but only recently has science uncovered the
answers to mysteries such as how separate herds coordinate movement over
many miles. Meredith's primer on elephantine
matters will help turn a reader's casual interest into a fascination.
Morgan, B.J.,
Lee, P.C., 2003. Forest elephant (Loxodonta africana cyclotis) stature
in the Reserve de Faune du Petit Loango, Gabon. Journal of Zoology 259,
337-344.
Abstract: The stature of forest elephants Loxodonta africana cyclotis
was determined at the Petit Loango Reserve over 14 months from January
to December 1998 and May to June 1999 using three measures: shoulder
height, hind footprint length and boli diameter. The shoulder height of
53 identified elephants was measured using photogrammetric methods. The
minimum estimated shoulder height was 69 cm from a young calf, and the
tallest animal was 216 cm. Hind footprint length and boli diameter data
were collected from unidentified individuals. The minimum footprint size
was 12.5 cm and the largest 35.3 cm. Boli diameter ranged from 4.0 to
16.0 cm. A comparison of the size categories with those of savanna
elephants in Amboseli National Park, Kenya, suggested a similar
distribution of size, age and population structure, despite a marked
difference in overall stature. These are the first data for measures of
African forest elephant size compared to African savanna elephant size.
Such data may add morphological evidence supporting recent genetic work
suggesting that African forest elephants be re-classified as a distinct
species from the African savanna elephant.
Murata, Y.,
Nikaido, M., Sasaki, T., Cao, Y., Fukumoto, Y., Hasegawa, M., Okada, N.,
2003. Afrotherian phylogeny as inferred from complete mitochondrial
genomes. Mol Phylogenet Evol 28, 253-260.
Abstract: Afrotheria is a huge assemblage of various mammals
encompassing six orders that were once classified as distantly related
groups. This superordinal relationship may have resulted from the
break-up of Gondowanaland followed by the isolation of the African
continent between 105 and 40 million years ago. Although the monophyly
of Afrotheria is well supported by recent molecular studies, the
interrelationships within afrotherian mammals remain unclarified. In
this study, we determined the sequence of the complete mitochondrial
genomes of hyrax, golden mole, and elephant shrew. These sequences were
compared with those of other eutherians to analyze the phylogenetic
relationships among afrotherians and, in particular, those among
paenungulates. Our mitochondrial genome analysis supports the monophyly
of Tethytheria.
Nikaido, M.,
Nishihara, H., Hukumoto, Y., Okada, N., 2003. Ancient SINEs from African
endemic mammals. Mol Biol Evol 20, 522-527.
Abstract: Afrotheria is a newly recognized taxon comprising elephants,
hyraxes, sea cows, aardvarks, golden moles, tenrecs, and elephant
shrews, each of which originated in Africa. Although some members of
this taxon were once classified into distantly related groups, recent
molecular studies have demonstrated their close relationships. It was
suggested that this group emerged as a result of physical isolation of
the African continent during the successive breakup events of
Gondowanaland. In this study, a novel family of SINEs, designated
AfroSINEs, was isolated and characterized from the genomes of
afrotherians. This SINE family is distributed exclusively among the
afrotherian species, confirming their monophyletic relationships.
Furthermore, a distinct subfamily, which shares a deletion in the middle
region of the SINE, was identified. The distribution of this subfamily
is apparently restricted to the genomes of hyraxes, elephants, and sea
cows, suggesting monophyly of these three groups, which was previously
proposed as Paenungulata. We characterized the structures of the
AfroSINEs from all afrotherian representatives by PCR, and we discuss
how they were generated as well as the phylogenetic relationships of
their host species. Graduate School of Bioscience and Biotechnology,
Tokyo Institute of Technology, Yokohama, Japan.
Shimoyama,
M., Ninomiya, T., Ozaki, Y., 2003. Nondestructive discrimination of
ivories and prediction of their specific gravity by Fourier-transform
Raman spectroscopy and chemometrics. Analyst. 128, 950-953.
Abstract: Fourier-transform (FF) Raman spectroscopy and chemometrics
were used for nondestructive analysis of ivories. The discrimination of
five kinds of ivories, two subspecies of African elephant, mammoth,
hippopotamus, and sperm whale, was investigated, and a calibration model
for predicting their specific gravity was developed. FT-Raman spectra
were measured in situ for them and chemometrics analyses were carried
out for the 3050-350 cm(-1) region. The five kinds of ivories were
clearly discriminated from each other on the scores plots of two or
three principal components (PCs) obtained by principal component
analysis (PCA). The loadings plot for PC 1 shows that the discrimination
relies on the content ratio of organic collagenous protein and inorganic
hydroxyapatite of ivories. The loadings plot for PC 2 shows that bands
due to the CH3 and CH2 stretching modes of the protein also play a role
in the discrimination. Using partial least squares regression (PLSR), we
developed a calibration model that predicts the specific gravity of the
ivories from the FT-Raman spectra. The correlation coefficient and root
mean square error of cross validation (RMSECV) of this model were 0.980
and 0.024, respectively. Forensic Science Laboratory, Hyogo Prefectural
Police Headquarters, Shimoyamate-dori, Chuo-ku, Kobe 650-8510, Japan.
West, J.B.,
Fu, Z., Gaeth, A.P., Short, R.V., 2003. Fetal lung development in the
elephant reflects the adaptations required for snorkeling in adult life.
Respir Physiol Neurobiol 138, 325-333.
Abstract: The adult elephant is unique among mammals in that the pleural
membranes are thickened and the pleural cavity is obliterated by
connective tissue. It has been suggested that this peculiar anatomy
developed because the animal can snorkel at depth, and this behavior
subjects the microvessels in the parietal pleura to a very large
transmural pressure. To investigate the development of the parietal
pleura, the thickness of the endothoracic fascia (ET) was measured in
four fetal African elephants of approximate gestational age 111-130
days, and the appearances were compared with those in human, rabbit, rat
and mouse fetuses of approximately the same stage of lung organogenesis.
The mean thicknesses of ET in the elephant, human, rabbit, rat and mouse
were 403, 53, 29, 27 and 37 microm, respectively. This very early
development of a thick parietal pleura in the elephant fetus is
consistent with the hypothesis of a long history of snorkeling in the
elephant's putative aquatic ancestors. Department of Medicine,
University of California San Diego, 9500 Gilman Drive, La Jolla, CA
92093-0623, USA. jwest@ucsd.edu
Yang, F.,
Alkalaeva, E.Z., Perelman, P.L., Pardini, A.T., Harrison, W.R., O'Brien,
P.C., Fu, B., 2003. Reciprocal chromosome painting among human,
aardvark, and elephant (superorder Afrotheria) reveals the likely
eutherian ancestral karyotype. Proc Natl Acad Sci U S A 100,
1062-1066.
Abstract: The Afrotheria, a supraordinal grouping of mammals whose
radiation is rooted in Africa, is strongly supported by DNA sequence
data but not by their disparate anatomical features. We have used
flow-sorted human, aardvark, and African elephant chromosome painting
probes and applied reciprocal painting schemes to representatives of two
of the Afrotherian orders, the Tubulidentata (aardvark) and Proboscidea
(elephants), in an attempt to shed additional light on the evolutionary
affinities of this enigmatic group of mammals. Although we have not yet
found any unique cytogenetic signatures that support the monophyly of
the Afrotheria, embedded within the aardvark genome we find the
strongest evidence yet of a mammalian ancestral karyotype comprising 2n
= 44. This karyotype includes nine chromosomes that show complete
conserved synteny to those of man, six that show conservation as single
chromosome arms or blocks in the human karyotype but that occur on two
different chromosomes in the ancestor, and seven neighbor-joining
combinations (i.e., the synteny is maintained in the majority of species
of the orders studied so far, but which corresponds to two chromosomes
in humans). The comparative chromosome maps presented between human and
these Afrotherian species provide further insight into mammalian genome
organization and comparative genomic data for the Afrotheria, one of the
four major evolutionary clades postulated for the Eutheria.
Journal of
Indian Veterinary Assocaition Kerala. Journal of Indian Veterinary
Association Kerala 7[3], 1-64. 2002.
Ref Type: Journal (Full)
Alex, P.C.,
2002. The Musth, the vicious and the rogue elephants - a review. Journal
of Indian Veterinary Association Kerala 7, 26-27.
Anilkumar,
K., 2002. Phylogeny of elephants. Journal of Indian Veterinary
Association Kerala 7, 15-17.
Bist, S.S.,
2002. The status of the domesticated elephants in India. Journal of
Indian Veterinary Association Kerala 7, 4-7.
Chandrasekharan, K., 2002. Specific diseases of Asian elephants. Journal
of Indian Veterinary Association Kerala 7, 31-34.
Abstract: The earliest writing describing the diseases of elephants in
ancient literature said to be the works on "Gajasastra" (Elephantology)
written in Sanskrit by authors like Gautama, Narada, Mrigacharma,
Rajaputra and Vyasa. "Hasthyayurveda" a legendary book in Sanskrit
written by a safe Palakapya deals with some diseases, treatment,
desirable and undesirable points of selection, management practices and
some mythological aspects on the origin of elephants. The earliest book
in English dealing with diseases of elephants seems to be that of W.
Gilchrist "A practical treatise on the treatment of diseases of
elephants" published in 1848. Later Slym (1873), Sanderson (1878), Steel
(1885), Evans (1910), Herpburn (1913), Milroy (1922), Ptaff (1940),
Ferrier (1947), Utoke Gale (1974), Chandrasekharan (1979) and Panicker
(1985) have documented their findings on the incidence, etiology and
control of diseases of Asian elephants.
Eggert, L.S.,
Rasner, C.A., Woodruff, D.S., 2002. The evolution and phylogeography of
the African elephant inferred from mitochondrial DNA sequence and
nuclear microsatellite markers. Proc R Soc Lond B Biol Sci 269 ,
1993-2006.
Abstract: Recent genetic results support the recognition of two African
elephant species: Loxodonta africana, the savannah elephant, and
Loxodonta cyclotis, the forest elephant. The study, however,#10; did not
include the populations of West Africa, where the taxonomic affinities
of elephants have been much debated. We examined mitochondrial
cytochrome b control region sequences and four microsatellite#10; loci
to investigate the genetic differences between the forest and savannah
elephants of West and Central Africa. We then combined our data with
published control region sequences from across Africa to#10; examine
patterns at the continental level. Our analysis reveals several deeply
divergent lineages that do not correspond with the currently recognized
taxonomy: (i) the forest elephants of Central Africa;#10; (ii) the
forest and savannah elephants of West Africa; and (iii) the savannah
elephants of eastern, southern and Central Africa. We propose that the
complex phylogeographic patterns we detect in African#10; elephants
result from repeated continental-scale climatic changes over their
five-to-six million year evolutionary history. Until there is consensus
on the taxonomy, we suggest that the genetic and ecological#10;
distinctness of these lineages should be an important factor in
conservation management planning. #10;
Forsyth, I.A.,
Wallis, M., 2002. Growth hormone and prolactin--molecular and functional
evolution. J Mammary Gland Biol Neoplasia 7, 291-312.
Abstract: Growth hormone, prolactin, the fish hormone, somatolactin, and
related mammalian placental hormones, including placental lactogen, form
a family of polypeptide hormones that share a common tertiary structure.
They produce their biological effects by interacting with and dimerizing
specific single transmembrane-domain receptors. The receptors belong to
a superfamily of cytokine receptors with no intrinsic tyrosine kinase,
which use the Jak-Stat cascade as a major signalling pathway. Hormones
and receptors are thought to have arisen as a result of gene duplication
and subsequent divergence early in vertebrate evolution. Mammalian
growth hormone and prolactin show a slow basal evolutionary rate of
change, but with episodes of accelerated evolution. These occurred for
growth hormone during the evolution of the primates and artiodactyls and
for prolactin in lineages leading to rodents, elephants, ruminants, and
man. Placental lactogen has probably evolved independently on three
occasions, from prolactin in rodents and ruminants and from growth
hormone in man. Receptor sequences also show variable rates of
evolution, corresponding partly, but not completely, with changes in the
ligand. A principal biological role of growth hormone, the control of
postnatal growth, has remained quite consistent throughout vertebrate
evolution and is largely mediated by insulin-like growth factors.
Prolactin has many and diverse roles. In relation to lactation, the
relative roles of growth hormone and prolactin vary between species.
Correlation between the molecular and functional evolution of these
hormones is very incomplete, and it is likely that many important
functional adaptations involved changes in regulatory elements, for
example, altering tissue of origin or posttranscriptional processing,
rather than change of the structures of the proteins themselves. The
Babraham Institute, Babraham, Cambridge, United Kingdom. isabel.forsyth@bbsrc.ac.uk
Hashimoto,
K., 2002. Historical accounts of elephants imported before the Meiji
period. Journal of Veterinary Medicine, Japan 55, 776-780.
Murali, K.,
2002. An introduction to Hastyayurveda. Journal of Indian Veterinary
Association Kerala 7, 54,63-63.
Poulakakis,
N., Theodorou, G.E., Zouros, E., Mylonas, M., 2002. Molecular phylogeny
of the extinct pleistocene dwarf elephant Palaeoloxodon antiquus
falconeri from Tilos Island, Dodekanisa, Greece. J Mol Evol 55,
364-374.
Abstract: A partial sequence of cytochrome b (228 bp) gene of
mitochondrial DNA was successfully determined from rib bones of the
dwarf elephant Palaeoloxodon antiquus falconeri BUSK, which were
excavated from Charkadio cave of the island of Tilos, Dodekanisa,
Greece. This is the first report of DNA sequence of a dwarf elephant.
The sequences were used to examine the phylogenetic relationships among
Elephantidae. Phylogenetic trees reconstructed by the neighbor-joining
and maximum parsimony methods provided identical topologies. The results
support the "Palaeoloxodon-Elephas" clade, which is consistent with
previous morphological reports according to which Palaeoloxodon is more
closely related to Elephas than to Loxodonta or Mammuthus.
Roca, A.L.,
Georgiadis, N., Pecon-Slattery, J., O'Brien, S.J., 2002. Genetic
evidence for two species of elephant in Africa. Science 293,
1473-1477.
Abstract: Elephants from the tropical forests of Africa are
morphologically distinct from savannah or bush elephants. Dart-biopsy
samples from 195 free-ranging African elephants in 21 populations were
examined for DNA sequence variation in four nuclear genes (1732 base
pairs). Phylogenetic distinctions between African forest elephant and
savannah elephant populations corresponded to 58% of the difference in
the same genes between elephant genera Loxodonta (African) and Elephas
(Asian). Large genetic distance, multiple genetically fixed nucleotide
site differences, morphological and habitat distinctions, and extremely
limited hybridization of gene flow between forest and savannah elephants
support the recognition and conservation management of two African
species: Loxodonta africana and Loxodonta cyclotis.
Schweitzer,
M., Hill, C.L., Asara, J.M., Lane, W.S., Pincus, S.H., 2002.
Identification of immunoreactive material in mammoth fossils. J Mol Evol
55, 696-705.
Abstract: Department of Microbiology, Montana State University, Bozeman,
MT 59717, USA. schweitzer@montana.edu
The fossil record represents a history of life on this planet. Attempts
to obtain molecular information from this record by analysis of nucleic
acids found within fossils of extreme age have been unsuccessful or
called into question. However, previous studies have demonstrated the
long-term persistence of peptides within fossils and have used
antibodies to extant proteins to demonstrate antigenic material. In this
study we address two questions: Do immunogenic/antigenic materials
persist in fossils? and; Can fossil material be used to raise antibodies
that will cross-react with extant proteins? We have used material
extracted from a well-preserved 100000-300000-year-old mammoth skull to
produce antisera. The specificity of the antisera was tested by ELISA,
western blotting, and immunohistochemistry. It was demonstrated that
antisera reacted specifically with the fossils and not the surrounding
sediments. Reactivity of antisera with modern proteins and tissues was
also demonstrated, as was the ability to detect evolutionary
relationships via antibody-antigen interactions. Mass spectrometry
demonstrated the presence of amino acids and specific peptides within
the fossil. Peptides were purified by anion-exchange chromatography and
sequenced by tandem mass spectrometry. The collagen-derived peptides may
have been the source of at least some of the immunologic reactivity, but
the antisera identified molecules that were not observed by mass
spectrometry, indicating that immunologic methods may have greater
sensitivity. Although the presence of peptides and amino acids was
demonstrated, the exact nature of the antigenic material was not fully
clarified. This report demonstrates that antibodies may be used to
obtain information from the fossil record.
Scigliano,
E., 2002. Love, war, and circuses : the age-old relationship between
elephants and humans. Houghton Mifflin, Boston.
Sethumadhavan,
T.P., 2002. Who will win the battle? man or elephant? Journal of Indian
Veterinary Association Kerala 7, 3.
Vogel, G.,
2002. Ecology. African elephant species splits in two. Science 293,
1414.
Brody, R.H.,
Edwards, H.G.M., Pollard, A.M., 2001. Chemometric methods applied to the
differentiation of Fourier-transform Raman spectra of ivories. Analytica
Chimica Acta 427, 223-232.
Cozzi, B.,
Spagnoli, S., Bruno, L., 2001. An overview of the central nervous system
of the elephant through a critical appraisal of the literature published
in the XIX and XX centuries. Brain Res Bull 54, 219-227.
Abstract: The two species of elephants (Indian: Elephas maximus and
African: Loxodonta africana) possess the largest brain among land
mammals. Due to its size, the elephant brain is discussed in virtually
every paper dealing with the evolution of the central nervous system of
mammals and comparative brain size. Studies on the social habits of
elephants also deal with the skills and the "intelligence" and brain
size of these species. Yet most of the descriptions and conclusions
reported in comparative studies rely on second-hand data derived from
investigations performed several decades before, often dating as far
back as the XIX century. Furthermore, many of the original papers
actually describing gross and detailed features of the brain of
elephants are either no longer available, are written in languages other
than English, or are difficult to trace. The present study gives a short
description of the anatomy of the central nervous system of elephants,
with special attention to its distinctive features, reports all
available literature on the subject, and briefly discusses its origins
and rationale.
Fleischer,
R.C., Perry, E.A., Muralidharan, K., Stevens, E.E., Wemmer, C.M., 2001.
Phylogeography of the Asian elephant (Elephas maximus) based on
mitochondrial DNA. Evolution 55, 1882-1892.
Abstract: Populations of the Asian elephant (Elephas maximus) have been
reduced in size and become highly fragmented during the past 3000 to
4000 years. Historical records reveal elephant dispersal by humans via
trade and war. How have these anthropogenic impacts affected genetic
variation and structure of Asian elephant populations? We sequenced
mitochondrial DNA (mtDNA) to assay genetic variation and phylogeography
across much of the Asian elephant's range. Initially, we compared
cytochrome b sequences (cyt b) between 9 Asian and 5 African elephants
and used the fossil-based age of their separation (_5 million years
ago) to obtain a rate of about 0.013 (95% CI=0.011-0.018) corrected
sequence divergence per million years. We also assessed variation in
part of the mtDNA control region (CR) and adjacent tRNA genes in 57
Asian elephants from 7 countries (Sri Lanka, India, Nepal, Myanmar,
Thailand, Malaysia, and Indonesia). Asian elephants had typical levels
of mtDNA variation, and coalescence analyses suggested their populations
were growing in the late Pleistocene. Reconstructed phylogenies
revealed 2 major clades (A and B) differing on average by
HKY85/GAMMA-corrected distances of 0.020 for cyt b and 0.050 for the CR
segment (corresponding to a coalescence time based on our cyt b rate
of _1.2 million years). Individuals of both major clades existed in
all locations, but Indonesia and Malaysia. Most elephants from Malaysia
and all from Indonesia were in well-supported, basal clades within clade
A, thus supporting their status as evolutionarily significant units (ESUs).
The proportion of clade A individuals decreased to the north, which
could result from retention and subsequent loss of ancient lineages in
long-term stable populations or, perhaps more likely, via recent mixing
of 2 expanding populations that were isolated in the mid-Pleistocene.
The distribution of clade A individuals appeared to be impacted by human
trade in elephants among Myanmar, Sri Lanka, and India, and the
subspecies and ESU statuses of Sri Lankan elephants were not supported
by molecular data.
Greenwood,
A.D., Lee, F., Capelli, C., DeSalle, R., Tikhonov, A., Marx, P.A.,
MacPhee, R.D., 2001. Evolution of endogenous retrovirus-like elements of
the woolly mammoth (Mammuthus primigenius) and its relatives. Mol Biol
Evol 18, 840-870.
Abstract: Endogenous retrovirus-like elements characterizable by a
leucine tRNA primer (ERV-Ls) are reiterated genomic sequences known to
be widespread in mammals, including humans. They may have arisen from an
ancestral foamy virus-like element by successful germ line infection
followed by copy number expansion. However, among mammals, only primates
and rodents have thus far exhibited high copy number amplification and
sequence diversification. Conventionally, empirical studies of proviral
amplification and diversification have been limited to extant species,
but taxa having good Quaternary fossil records could potentially be
investigated using the techniques of "ancient" DNA research. To examine
evolutionary parameters of ERV-Ls across both time and taxa, we
characterized this proviral class in the extinct woolly mammoth (Mammuthus
primigenius) and living elephants, as well as extant members of the
larger clade to which they belong (Uranotheria, a group containing
proboscideans, sirenians, hyraxes, and their extinct relatives).
Ungulates and carnivores previously analyzed demonstrated low copy
numbers of ERV-L sequences, and thus it was expected that uranotheres
should as well. Here, we show that all uranothere taxa exhibit
unexpectedly numerous and diverse ERV-L sequence complements, indicating
active expansion within this group of lineages. Selection is the most
parsimonious explanation for observed differences in ERV-L distribution
and frequency, with relative success being reflected in the persistence
of certain elements over a variety of sampled time depths (as can be
observed by comparing sequences from fossil and extant elephantid
samples).
Haynes, G.
Elephant landscapes: human foragers in the world of mammoths, mastodons,
and elephants. The World of Elephants-International Congress. 571-576.
2001.
Ref Type: Conference Proceeding
Abstract: Human groups able to subsist by opportunistic exploitation of
proboscideans would be afforded abundant environmental clues to prey
health and density, along with superior nutrients and other advantages
such as information-rich trail networks.
Hecht, J.
Telltale bones. New Scientist [2312], 14. 2001.
Ref Type: Magazine Article
Kirkman, S.,
., Wallace, E.D., van Aarde, R.J., Potgieter, H.C., 2001. Steroidogenic
correlates of pregnancy in the rock hyrax (Procavia capensis). Life
Sciences 68, 2061-2072.
Abstract: In pregnant rock hyraxes (P. capensis) isolated leucocytes
metabolize both [3H]pregnenolone and [3H]progesterone while whole blood,
erythrocytes and an erythrocyte/leucocyte mixture only metabolized
[3H]progesterone. Plasma displayed no tendency to metabolically convert
any one of these two steroids. In whole blood, [3H]progesterone appears
to be converted to 5alpha-pregnane-3,20-dione and a compound with
chromatographic properties similar to that of
5alpha-pregnan-3alpha-ol-20-one. 5alpha-Pregnane-3,20-dione exhibited a
high relative binding affinity for the uterine progesterone receptor
(94%), but 5alpha-pregnan-3alpha-ol-20-one displayed very little
affinity for the same receptor (0.4%). 5alpha-Pregnane-3,20-dione may
therefore aid in the maintenance of pregnancy. Corpora lutea metabolized
progesterone to 17alpha-hydroxyprogesterone, a compound exhibiting no
progestational function because of its low relative binding affinity for
the uterine progesterone receptor (2%). Progesterone appears to be the
main product of the corpus luteum. However, 5alpha-pregnane-3,20-dione
circulated at concentrations approximately 8.5 times higher than
progesterone, probably due to the metabolic conversion of progesterone
to 5alpha-pregnane-3,20-dione by the blood. We conclude that in the
hyrax, progesterone, produced by the corpora lutea, enters the
circulation, where it is reduced to 5alpha-pregnanes.
5alpha-Pregane-3,20-dione may then be transported to the uterus where it
binds to the progesterone receptor to assist in the maintenance of
pregnancy. This mechanism appears to be analogous to that of the African
elephant (Loxodonta africana) which is phylogenetically related to the
hyrax, except that in the elephant the 5alpha-reduced metabolites are
produced by luteal tissue and not the blood.
Lister, A.M.,
Sher, A.V., 2001. The origin and evolution of the woolly mammoth.
Science 294, 1094-1097.
Abstract: The mammoth lineage provides an example of rapid adaptive
evolution in response to the changing environments of the Pleistocene.
Using well-dated samples from across the mammoth's Eurasian range, we
document geographical and chronological variation in adaptive
morphology. This work illustrates an incremental (if mosaic)
evolutionary sequence but also reveals a complex interplay of local
morphological innovation, migration, and extirpation in the origin and
evolution of a mammalian species. In particular, northeastern Siberia is
identified as an area of successive allopatric innovations that
apparently spread to Europe, where they contributed to a complex pattern
of stasis, replacement, and transformation.
Mahasavangkul,
S. Domestic Elephant Status and Management in Thailand. A Research
Update on Elephants and Rhinos; Proceedings of the International
Elephant and Rhino Research Symposium, Vienna, June 7-11, 2001. 71-82.
2001. Vienna, Austria, Schuling Verlag. 2001.
Ref Type: Conference Proceeding
McComb, K.,
Moss, C., Durant, S.M., Baker, L., Sayialel, S., 2001. Matriarchs as
repositories of social knowledge in African elephants. Science 292,
491-494.
Abstract: Despite widespread interest in the evolution of social
intelligence, little is known about how wild animals acquire and store
information about social companions or whether individuals possessing
enhanced social knowledge derive biological fitness benefits. Using
playback experiments on African elephants (Loxodonta africana), we
demonstrated that the possession of enhanced discriminatory abilities by
the oldest individual in a group can influence the social knowledge of
the group as a whole. These superior abilities for social discrimination
may result in higher per capita reproductive success for female groups
led by older individuals. Our findings imply that the removal of older,
more experienced individuals, which are often targets for hunters
because of their large size, could have serious consequences for
endangered populations of advanced social mammals such as elephants and
whales.
Miller, D.L.,
Dougherty, M.M., Decker, S.J., Bossart, G.D., 2001. Ultrastructure of
the spermatozoa from a Florida manatee (Trichechus manatus latirostris).
Anat Histol Embryol 30, 253-256.
Abstract: Semen was opportunistically collected from a free-ranging,
10-year-old, 275 cm (total length) Florida manatee (Trichechus manatus
latirostris) during rehabilitation treatments. Ultrastructure of the
spermatozoa was examined by scanning and transmission electron
microscopy and differed slightly from that described for other mammals.
Comparisons to the manatee's closest phylogenetic relatives, the
elephant and hyrax, were made. The manatee spermatozoa had a similar
acrosome but a distinct annulus and lacked the dense bodies observed in
the neck of the elephant spermatozoa. Additionally, manatee spermatozoa
lacked the lateral vacuoles observed in the nuclear chromatin from of
the hyrax spermatozoa. These data add to our understanding of manatees
and allow for comparative studies with other species that may be useful
in phylogenetic and reproductive studies.
Murphy, W.J.,
Eizirik, E., Johnson, W.E., Zhang, Y.P., Ryder, O.A., O'Brien, S.J.,
2001. Molecular phylogenetics and the origins of placental mammals.
Nature 409, 614-618.
Abstract: The precise hierarchy of ancient divergence events that led to
the present assemblage of modern placental mammals has been an area of
controversy among morphologists, paleontologists and molecular
evolutionists. Here we address the potential weaknesses of limited
character and taxon sampling in a comprehensive molecular phylogenetic
analysis of 64 species sampled across all extant orders of placental
mammals. We examined sequence variation in 18 homologous gene segments
(including nearly 10,000 base pairs) that were selected for maximal
phylogenetic informativeness in resolving the hierarchy of early
mammalian divergence. Phylogenetic analyses identify four primary
superordinal clades: (I) Afrotheria (elephants, manatees, hyraxes,
tenrecs, aardvark and elephant shrews); (II) Xenarthra (sloths,
anteaters and armadillos); (III) Glires (rodents and lagomorphs), as a
sister taxon to primates, flying lemurs and tree shrews; and (IV) the
remaining orders of placental mammals (cetaceans, artiodactyles,
perissodactyles, carnivores, pangolins, bats and core insectivores). Our
results provide new insight into the pattern of the early placental
mammal radiation.
Okayama, T.,
Sugardjito, J., Yusuf, I. Mitochondrial DNA Analysis of Sumatran
Elephants. A Research Update on Elephants and Rhinos; Proceedings of the
International Elephant and Rhino Research Symposium, Vienna, June 7-11,
2001. 278-281. 2001. Vienna, Austria, Schuling Verlag. 2001.
Ref Type: Conference Proceeding
Schulte, B.A.
Examining Ideas on the Evolution of Musth. A Research Update on
Elephants and Rhinos; Proceedings of the International Elephant and
Rhino Research Symposium, Vienna, June 7-11, 2001. 287. 2001. Vienna,
Austria, Schuling Verlag. 2001.
Ref Type: Conference Proceeding
van Dijk,
M.A., Madsen, O., Catzeflis, F., Stanhope, M.J., De Jong, W.W., Pagel,
M., 2001. Protein sequence signatures support the African clade of
mammals. Proc Natl Acad Sci U S A 98, 188-189.
West, J.B.,
2001. Snorkel breathing in the elephant explains the unique anatomy of
its pleura. Respiratory Physiology 126, 1-8.
Abstract: It has been known for over 300 years that the anatomy of the
elephant lung is unique among mammals in that the pleural cavity is
obliterated by connective tissue. However no satisfactory explanation
has been advanced. Recent studies suggest that the elephant has an
aquatic ancestry and the trunk may have developed for snorkeling. In
addition, the modern day elephant is the only mammal that can remain
submerged far below the surface of the water while snorkeling. The
resulting differences of pressures within the thorax mean that the small
blood vessels of the pleura are in great danger of rupturing or causing
severe edema. The same distribution of pressures occurs when the animal
raises water inside its trunk prior to drinking although in this case
the pressure differences are relatively short-lived. Evolution has
provided a remarkable solution to this problem by replacing the normally
delicate parietal and visceral pleurae by dense connective tissue, and
separating the two pleurae by loose connective tissue to allow some
sliding movement.
Whitehouse,
A.M., Harley, E.H., 2001. Post-bottleneck genetic diversity of elephant
populations in South Africa,revealed using microsatellite analysis. Mol
Ecol 10, 2139-2149.
Abstract: Widespread hunting had fragmented and severely reduced
elephant populations in South Africa by 1900. Elephant numbers increased
during the 1900s, although rates of recovery of individual populations
varied. The Kruger National Park elephant population increased rapidly,
to more than 6000 by 1967, with recruitment boosted by immigration from
Mozambique. The Addo Elephant National Park population was reduced to 11
elephants in 1931 and remains relatively small (n = 325). Loss of
genetic variation is expected to occur whenever a population goes
through a bottleneck, especially when post-bottleneck recovery is slow.
Variation at nine polymorphic microsatellite loci was analysed for
Kruger and Addo elephants, as well as museum specimens of Addo elephants
shot prior to the population bottleneck. Significantly reduced genetic
variation and heterozygosity were observed in Addo in comparison to
Kruger (mean alleles/locus and H(E): Addo 1.89, 0.18; Kruger 3.89,
0.44). Two alleles not present in the current Addo population were
observed in the museum specimens. Addo elephants represent a genetic
subset of the Kruger population, with high levels of genetic
differentiation resulting from rapid genetic drift. The Kruger
population is low in genetic diversity in comparison to East African
elephants, confirming this population also suffered an appreciable
bottleneck.
Alexander,
S., 2000. The Astonishing Elephant. Random House, New York.
Anderson, D.,
Wood, M. Web-based Search Templates on Elephants. Elephants: Cultural,
Behavioral, and Ecological Perspectives; Program and Abstracts of the
Workshop. 8. 2000. Davis, CA. 2000.
Ref Type: Conference Proceeding
Debuyst, R.,
Callens, F., Frechen, M., Dejehet, F., 2000. ESR study of elephant tooth
enamel from the Karlich-Seeufer site in Germany. Appl Radiat Isot 52,
1327-1336.
Abstract: Enamel from 6 different positions in a well preserved elephant
tooth from the Karlich-Seeufer site in Germany has been irradiated up to
32 kGy. The X-band (v = 9.5 GHz) ESR spectra of two subsamples have been
decomposed into three real components with Maximum Likelihood Common
Factor Analysis (MLCFA). One of these components due to orthorhombic
CO2- radicals is predominant. Dose response curves for the contributions
of these MLCFA components and for different heights in the ESR spectra
have been obtained and fitted with different models. Depending on the
model, the equivalent dose for the preferably used height at g = 1.9973,
due to CO2-, ranges from 70 to 130 Gy. Due to a very low uranium and
thorium content in both enamel and dentine (< or = approximately 10 ppb)
and to an important external y-attenuation, the ages fluctuate between
300 and 575 ka.
Fernando, P.,
Pfrender, M.E., Encalada, S.E., Lande, R., 2000. Mitochondrial DNA
variation, phylogeography and population structure of the Asian
elephant. Heredity 84, 362-372.
Abstract: We report the first genetic analysis of free-ranging Asian
elephants (Elephas maximus). We sampled 118 elephants from Sri Lanka,
Bhutan/North India, and Laos/Vietnam by extracting DNA from dung, PCR
amplifying and sequencing 630 nucleotides of mtDNA, including part of
the variable left domain of the control region. Comparison with African
elephant (Loxodonta africana) sequences indicated a relatively slow
molecular clock in the Proboscidea with a sequence divergence of
_1%/million years. Genetic diversity within Asian elephants was low,
suggesting a small long-term effective population size. 17 haplotypes
were identified within Asian elephants, which clustered into 2
well-differentiated assemblages with an estimated Pliocene divergence of
2.5-3.5 million years ago. The 2 assemblages showed incomplete
geographical partitioning, suggesting allopatric divergence and
secondary admixture. On the mainland, little genetic differentiation was
observed between elephant populations of Bhutan and India or Laos and
Vietnam. A significant difference in haplotype frequencies but
relatively weak subdivision was observed between the Bhutan-India and
Laos-Vietnam regions. Significant genetic differentiation was observed
between the mainland and Sri Lanka and between northern, mid-latitude
and southern regions in Sri Lanka.
Hall, T.,
2000. To the elephant graveyard. John Murray, London.
Hart, L.A.
The Mahout-Elephant Relationship: Ancient and Modern Versions.
Elephants: Cultural, Behavioral, and Ecological Perspectives; Program
and Abstracts of the Workshop. 13. 2000. Davis, CA. 2000.
Ref Type: Conference Proceeding
Shelton, J.
Dancing and Dying: The Display of Elephants in Ancient Roman Arenas.
Elephants: Cultural, Behavioral, and Ecological Perspectives; Program
and Abstracts of the Workshop. 21. 2000. Davis, CA. 2000.
Ref Type: Conference Proceeding
Thomas, M.G.,
Hagelberg, E., Jones, H.B., Yang, Z., Lister, A.M., 2000. Molecular and
morphological evidence on the phylogeny of the Elephantidae. Proceedings
of the Royal Society of London SeriesB, Biological-Sciences 267:1561,
2493-2500.
Abstract: The African and Asian elephants and the mammoth diverged ca.
4-6 million years ago and their phylogenetic relationship has been
controversial. Morphological studies have suggested a mammoth-Asian
elephant relationship, while molecular studies have produced conflicting
results. We obtained cytochrome b sequences of up to 545 base pairs from
five mammoths, 14 Asian and eight African elephants. A high degree of
polymorphism is detected within species. With a dugong sequence used as
the outgroup, parsimony and maximum-likelihood analyses support a
mammoth-African elephant clade. As the dugong is a very distant outgroup,
we employ likelihood analysis to root the tree with a molecular clock,
and use bootstrap and Bayesian analyses to quantify the relative support
for different topologies. The analyses support the mammoth-African
elephant relationship, although other trees cannot be rejected.
Ancestral polymorphisms may have resulted in gene trees differing from
the species phylogeny. Examination of morphological data, especially
from primitive fossil members, indicates that some supposed
synapomorphies between the mammoth and Asian elephant are variable,
others convergent or autapomorphous. A mammoth-African elephant
relationship is not excluded. Our results highlight the need, in both
morphological and molecular phylogenetics, for multiple markers and
close attention to within-taxon variation and outgroup selection.
Victor, S.,
Nayak, V.M., 2000. Evolutionary anticipation of the human heart. Ann R
Coll Surg Engl 82, 297-302.
Abstract: We have studied the comparative anatomy of hearts from fish,
frog, turtle, snake, crocodile, birds (duck, chicken, quail), mammals
(elephant, dolphin, sheep, goat, ox, baboon, wallaby, mouse, rabbit,
possum, echidna) and man. The findings were analysed with respect to the
mechanism of evolution of the heart.
Wallis, M.,
2000. Episodic evolution of protein hormones: molecular evolution of
pituitary prolactin. J Mol Evol 50, 465-473.
Abstract: Previous studies have shown that pituitary growth hormone
displays an episodic pattern of evolution, with a slow underlying
evolutionary rate and occasional sustained bursts of rapid change. The
present study establishes that pituitary prolactin shows a similar
pattern. During much of tetrapod evolution the sequence of prolactin has
been strongly conserved, showing a slow basal rate of change (approx
0.27x10(9) substitutions/amino acid site/year). This rate has increased
substantially ( approximately 12- to 38-fold) on at least four occasions
during eutherian evolution, during the evolution of primates,
artiodactyles, rodents, and elephants. That these increases are real and
not a consequence of inadvertent comparison of paralogous genes is shown
(for at least the first three groups) by the fact that they are confined
to mature protein coding sequence and not apparent in sequences coding
for signal peptides or when synonymous substitutions are examined.
Sequences of teleost prolactins differ markedly from those of tetrapods
and lungfish, but during the course of teleost evolution the rate of
change of prolactin has been less variable than that of growth hormone.
It is concluded that the evolutionary pattern seen for prolactin shows
long periods of near-stasis interrupted by occasional bursts of rapid
change, resembling the pattern seen for growth hormone in general but
not in detail. The most likely basis for these bursts appears to be
adaptive evolution though the biological changes involved are relatively
small.
Whitehouse,
A.M., Hall-Martin, A.J., 2000. Elephants in Addo Elephant National Park,
South Africa: Reconstruction of the population's history. Oryx 34,
46-55.
Abstract: The history of the Addo elephant population in South Africa,
from the creation of the Addo Elephant National Park (AENP) in 1931 to
the present (every elephant currently living within the park is known),
was reconstructed. Photographic records were used as a primary source of
historical evidence, in conjunction with all documentation on the
population. Elephants can be identified in photographs taken throughout
their life by study of the facial wrinkle patterns and blood vessel
patterns in their ears. These characteristics are unique for each
elephant and do not change during the individual's life. The life
histories of individual elephants were traced: dates of birth and death
were estimated and, wherever possible, the identity of the individual's
mother was ascertained. An annual register of elephants living within
the population, from 1931 to the present, was compiled, and maternal
family trees constructed. Preliminary demographic analyses for the
period 1976-98 are presented. The quantity and quality of photographs
taken during these years enabled thorough investigation of the life
histories of all elephants. Prior to 1976, insufficient photographs were
available to provide reliable data on the exact birth dates and mothers'
identities for every calf born. However, data on annual recruitment and
mortality are considered sufficiently reliable for use in analyses of
the population's growth and recovery.
Barriel, V.,
Thuet, E., Tassy, P., 1999. Molecular phylogeny of Elephantidae. Extreme
divergence of the extant forest African elephant. C R Acad Sci III 322,
447-454.
Abstract: A phylogenetic study of the Elephantidae (Proboscidea,
Mammalia) is based on the cytochrome b mitochondrial gene: 31 terminals,
that is, all known sequences, one non-elephantid proboscidean, the
extinct American mastodon, and four outgroups. The data set includes 11
new sequences with the first published sequence of the forest African
elephant, L. a. cyclotis. The analyses of extant taxa only and of both
extant and extinct taxa show that L. a. cyclotis is highly divergent
from L. a. africana. It is as divergent from L. a. africana as Loxodonta
is divergent from Elephas. Southern L. a. africana form a clade. The
continental subspecies E. m. indicus is paraphyletic with individuals
from India and Thailand closer to E. m. maximus (Sri-Lanka). Members of
Mammuthus primigenius are more closely related to Loxodonta although
they do not form a clade; two specimens of M. primigenius are closer to
L. a. africana making the genus Loxodonta paraphyletic. The latter
conclusion may be partly due to unequal length of the various
polymorphic mammoth sequences.
Chatkupt, T.T.,
Sollod, A.E., Sarobol, S., 1999. Elephants in Thailand: determinants of
health and welfare in working populations
531. J. Appl. Anim Welf. Sci. 2, 187-203.
Abstract: The Asian elephant (Elephas maximus) has played a prominent
role in Thai history and society. However, in the face of modernization,
elephant handlers have been struggling to justify their continued
ownership. As a result, working elephants may still encounter situations
in which their health and welfare are jeopardized. This study developed
both a survey instrument and a visual assessment to describe and
evaluate the health and living conditions of elephants encountered in a
variety of work and living situations. These situations were found to be
significantly associated with whether or not an elephant received proper
husbandry or was in good body condition. These results may prove
valuable in predicting the welfare of elephants according to work and
living situations
Gaeth, A.P.,
Short, R.V., Renfree, M.B., 1999. The developing renal, reproductive,
and respiratory systems of the African elephant suggest an aquatic
ancestry. Proc Natl Acad Sci U S A 96, 5555-5558.
Abstract: The early embryology of the elephant has never been studied
before. We have obtained a rare series of African elephant (Loxodonta
africana) embryos and fetuses ranging in weight from 0.04 to 18.5 g,
estimated gestational ages 58-166 days (duration of gestation is
approximately 660 days). Nephrostomes, a feature of aquatic vertebrates,
were found in the mesonephric kidneys at all stages of development
whereas they have never been recorded in the mesonephric kidneys of
other viviparous mammals. The trunk was well developed even in the
earliest fetus. The testes were intra-abdominal, and there was no
evidence of a gubernaculum, pampiniform plexus, processus vaginalis, or
a scrotum, confirming that the elephant, like the dugong, is one of the
few primary testicond mammals. The paleontological evidence suggests
that the elephant's ancestors were aquatic, and recent immunological and
molecular evidence shows an extremely close affinity between present-day
elephants and the aquatic Sirenia (dugong and manatees). The evidence
from our embryological study of the elephant also suggests that it
evolved from an aquatic mammal.
Greenwood,
A.D., Capelli, C., Possnert, G., Paabo, S., 1999. Nuclear DNA sequences
from late Pleistocene megafauna. Mol Biol Evol 16, 1466-1473.
Abstract: We report the retrieval and characterization of multi- and
single-copy nuclear DNA sequences from Alaskan and Siberian mammoths (Mammuthus
primigenius). In addition, a nuclear copy of a mitochondrial gene was
recovered. Furthermore, a 13,000-year-old ground sloth and a
33,000-year-old cave bear yielded multicopy nuclear DNA sequences. Thus,
multicopy and single-copy genes can be analyzed from Pleistocene faunal
remains. The results also show that under some circumstances, nucleotide
sequence differences between alleles found within one individual can be
distinguished from DNA sequence variation caused by postmortem DNA
damage. The nuclear sequences retrieved from the mammoths suggest that
mammoths were more similar to Asian elephants than to African elephants.
Groning, K.,
Saller, M., 1999. Elephants - A Cultural and Natural History. Konemann,
Germany.
Rasmussen,
L.E.L., 1999. Evolution of chemical signals in the Asian elephant,
Elephas maximus: behavioural and ecological influences. Journal of
Biosciences 24, 241-251.
Abstract: In antiquity, the Asian elephant, Elephas maximus,
gradually spread southward and eastward to become a successfully
surviving, ecologically dominant megaherbivore in the tropical
environment of south-east Asia. The changing physical environment forced
dynamic fluxes in its social structure and altered its metabolism. Such
events shaped the production and ultimately the stability of certain
chemicals released by body effluvia. Some of these chemicals took on
significance as chemical signals and/or pheromones. This article
demonstrates by experimental and observational evidence, and
hypothesizes based on speculative reasoning, how and why specific
chemical signals evolved in the modern Asian elephant. Evidence,
including the functional criteria required by elephant social structure
and ecology, is presented for the hypothesis that the recently
identified female-emitted, male-received sex pheromone, (Z)-7-dodecenyl
acetate evolved first as a chemical signal. Subsequently, the
cohesiveness and harmony of small, matriarchally-led female groups were
strengthened by a female-to-female chemical signal, recently defined
behaviourally. The looser societal structure of freer, roaming males
also became bounded by chemical signals; for the males, breath and
temporal gland emissions, as well as urinary ones function in chemical
signaling. Basic knowledge about elephant chemical signals is now
linking chemical information to behaviour and beginning to demonstrate
how these signals affect elephant social structure and enable the
species to cope with environmental changes.
Rasmussen,
L.E.L., Schulte, B.A., 1999. Ecological and biochemical constraints on
pheromonal signaling systems in Asian elephants and their evolutionary
implications. In: Johnston, R.E., Muller-Schwarze, D., Sorenson, P.W.
(Eds.), Advances in Chemical Communication in Vertebrates 8. Kluwer/Academic/
Plenum Press, pp. 49-62.
Abstract: The Asian elephant is an unusual example of how intraspecies
chemical communication helps maintain societal cohesiveness within
familial and herd units. The amount of multi-directional chemical
communication is surprising, because long-lived elephants have a highly
organized society, are capable of trans-generational passage of
information, possess a sophisticated vocalization system, and are
capable of complex learning and tool use. This paper discusses the
ecological, behavioral, and biochemical aspects of chemical signals in
elephants from an evolutionary perspective. Diverse bodily emissions are
utilized as intraspecies chemical signals (including pheromones), often
with imposed biochemical constraints. In this chapter, chemosignals
released from the temporal gland secretions and breath of male Asian
elephants in musth and a urinary female-to-male preovulatory pheromone
are utilized as examples of these concepts. Furthermore, specific
behavioral and biochemical studies with (Z)-7-dodecenyl acetate (a
female-to-male urinary sex pheromone) demonstrate that social context
significantly influences responsivity (demonstrated by field studies in
Myanmar) and that additional biochemical requirements, perhaps lipocalin-like
proteins, may be required for full bioactivity. The remarkable
convergent evolution of (Z)-7-dodecenyl acetate, both structurally and
functionally, in elephants and Lepidoptera, allows the use in elephant
studies of effective biochemical tools developed for insect
investigations. This convergence of chemical signaling systems of
elephants and insects has several interesting implications.
Stone, R.,
1999. Paleontology. Siberian mammoth find raises hopes, questions.
Science 286, 867-877.
Waddell, P.J.,
Cao, Y., Hauf, J., Hasegawa, M., 1999. Using novel phylogenetic methods
to evaluate mammalian mtDNA, including amino acid-invariant sites-LogDet
plus site stripping, to detect internal conflicts in the data, with
special reference to the positions of hedgehog, armadillo, and elephant.
Syst Biol 48, 31-53.
Abstract: We look at the higher-order phylogeny of mammals, analyzing in
detail the complete mtDNA sequences of more than 40 species. We test the
support for several proposed superordinal relationships. To this end, we
apply a number of recently programmed methods and approaches, plus
better-established methods. New pairwise tests show highly significant
evidence that amino acid frequencies are changing among nearly all the
genomes studied when unvaried sites are ignored. LogDet amino acid
distances, with modifications to take into account invariant sites, are
combined with bootstrapping and the Neighbor Joining algorithm to
account for these violations of standard models. To weight the more
slowlyevolving sites, we exclude the more rapidly evolving sites from
the data by using "site stripping". This leads to changing optimal trees
with nearly all methods. The bootstrap support for many hypotheses
varies widely between methods, and few hypotheses can claim unanimous
support from these data. Rather, we uncover good evidence that many of
the earlier branching patterns in the placental subtree could be
incorrect, including the placement of the root. The tRNA genes, for
example, favor a split between the group hedgehog, rodents, and primates
versus all other sequenced placentals. Such a grouping is not ruled out
by the amino acid sequence data. A grouping of all rodents plus rabbit,
the old Glires hypothesis, is also feasible with stripped amino acid
data, and rodent monophyly is also common. The elephant sequence allows
confident rejection of the older taxon Ferungulata (Simpson, 1945). In
its place, the new taxa Scrotifera and Fereuungulata are defined. A new
likelihood ratio test is used to detect differences between the optimal
tree for tRNA versus that for amino acids. While not clearly significant
as made, some results indicate the test is tending towards significance
with more general models of evolution. Individual placement tests
suggest alternative positions for hedgehog and elephant. Congruence
arguments to support elephant and armadillo together are striking,
suggesting a superordinal group composed of Xenarthra and African
endemic mammals, which in turn may be near the root of the placental
subtree. Thus, while casting doubt on some recent conclusions, the
analyses are also unveiling some interesting new possibilities.
Zecchini, A.,
1999. Life and death of species. Reconstituted animals? Courrier de la
Nature 177, 22-27.
Abstract: This article gives an account of a breeding project, started
in 1921, to reconstitute the aurochs, which became extinct in 1627, from
existing breeds of cattle, and of a project to reconstitute the quagga (Equus
quagga), which became extinct in 1921, from crosses among zebra species.
The possibility of reconstituting the mammoth by obtaining semen from a
mammoth preserved in the permafrost of Siberia and using it to fertilize
elephant ova, followed by repeated backcrossing of hybrids to the
mammoth, using mammoth semen, is discussed.
Daniel, J.C.,
1998. The Asian elephant: a natural history. Natraj Publishers, Dehra
Dun, India.
Noro, M.,
Masuda, R., Dubrovo, I.A., Yoshida, M.C., Kato, M., 1998. Molecular
phylogenetic inference of the woolly mammoth Mammuthus primigenius,
based on complete sequences of mitochondrial cytochrome b and 12S
ribosomal RNA genes. J Mol Evol 46, 314-326.
Abstract: Complete sequences of cytochrome b (1,137 bases) and 12S
ribosomal RNA (961 bases) genes in mitochondrial DNA were successfully
determined from the woolly mammoth (Mammuthus primigenius), African
elephant (Loxodonta africana), and Asian elephant (Elephas maximus).
From these sequence data, phylogenetic relationships among three genera
were examined. Molecular phylogenetic trees reconstructed by the
neighbor-joining and the maximum parsimony methods provided an identical
topology both for cytochrome b and 12S rRNA genes. These results support
the "Mammuthus-Loxodonta" clade, which is contrary to some previous
morphological reports that Mammuthus is more closely related to Elephas
than to Loxodonta.
Shoshani, J.,
1998. Understanding proboscidean evolution: a formidable task. Trends in
Ecology and Evolution 13, 480-487.
Stanhope, M.J.,
Madsen, O., Waddell, V.G., Cleven, G.C., De Jong, W.W., Springer, M.S.,
1998. Highly congruent molecular support for a diverse superordinal
clade of endemic African mammals. Mol Phylogenet Evol 9, 501-508.
Abstract: A solution to higher level mammalian phylogeny is going to
depend on the congruent establishment of superordinal groupings followed
by a linking together of these clades. We present congruent and
convincing evidence from four disparate nuclear protein coding genes and
from a tandem alignment of the 12S-16S mitochondrial region, for a
superordinal clade of endemic African mammals that includes elephant
shrews, aardvarks, golden mole, elephants, sirenians, and hyraxes.
Because of strong support for golden mole as part of this clade, the
Insectivora are rendered paraphyletic or polyphyletic, with constrained
monophyly of the insectivores judged significantly worse in the vast
majority of tests. Branching arrangement within this clade remains
highly uncertain; however, a tandem alignment of the protein coding
genes suggests elephant shrew is the earliest African lineage. None of
the individual data sets or combinations of data sets support the widely
held view of a mirorder Tethytheria (Sirenia/Proboscidea), although only
a tandem alignment of protein coding and mitochondrial loci
significantly rejects this association. The majority of the data sets
and analyses provide strong support for Caviomorpha as part of a
monophyletic Rodentia.
Kania, S.A.,
Richman, L.K., Kennedy, M., Montali, R.J., Potgleter, L.N.D., 1997. The
isolation, detection, and cross-reactivity of Asian elephant IgG for the
development of serological diagnostic tests. Journal of Veterinary
Allergy and Clinical Immunology 5, 125-128.
Abstract: Asian elephant (Elephas maximus) IgG was isolated and purified
using a recombinant protein A and proteins G affinity matrix and DEAE
cibacron blue chromatography. Rabbits were inoculated with elephant IgG
to produce anti-Asian elephant IgG. Using an ELISA, it was determined
that the anti-Asian elephant sera has strong reactivity with Asian
elephant IgG and African elephant (Loxodonta africana) IgG, moderate
reactivity with manatee (Trichechus manatus latirostris) IgG and weaker
reactivity with IgG from hyrax (Procavia capensis) and black rhinoceros
(Diceros bicornis). Commercially available antisera produced against
cattle, deer, and rabbit IgG react weakly with Asian elephant IgG.
Madsen, O.,
Deen, P.M., Pesole, G., Saccone, C., De Jong, W.W., 1997. Molecular
evolution of mammalian aquaporin-2: further evidence that elephant shrew
and aardvark join the paenungulate clade. Mol Biol Evol 14,
363-371.
Maliarchuk,
B.A., 1997. Restriction analysis of the Enmynveem mammoth. Dokl Akad
Nauk 353, 423-425.
Meng, J.,
Shoshani, J., Ketten, D., 1997. Evolutionary evidence for infrasonic
sound and hearing in proboscideans. J. Vert. Paleo. 17, 64A-65A.
Ozawa, T.,
Hayashi, S., Mikhelson, V.M., 1997. Phylogenetic position of mammoth and
Steller's sea cow within Tethytheria demonstrated by mitochondrial DNA
sequences. J Mol Evol 44, 406-413.
Abstract: Here we report DNA sequences from mitochondrial cytochrome b
gene segments (1,005 base pairs per species) for the extinct woolly
mammoth (Mammuthus primigenius) and Steller's sea cow (Hydrodamalis
gigas) and the extant Asian elephant (Elephas maximus), the Western
Indian manatee (Trichechus manatus), and the hyrax (Procavia capensis).
These molecular data have allowed us to construct the phylogeny for the
Tethytheria. Our molecular data resolve the trichotomy between the two
species of living elephants and the mammoth and confirm that the mammoth
was more closely related to the Asian elephant than to the African
elephant. Our data also suggest that the sea cow-dugong divergence was
likely as ancient as the dugong-manatee split, and it appears to have
been much earlier (22 million years ago) than had been previously
estimated (4-8 million years ago) by immunological comparison.
Rasmussen,
L.E., Lee, T.D., Zhang, A., Roelofs, W.L., Daves, G.D.Jr., 1997.
Purification, identification, concentration and bioactivity of
(Z)-7-dodecen-1-yl acetate: sex pheromone of the female Asian elephant,
Elephas maximus. Chemical Senses 22, 417-437.
Abstract: In their natural ecosystems, adult male and female Asian
elephants, Elephas maximus, live separately. For several weeks prior to
ovulation, female elephants release a substance in their urine which
elicits a high frequency of non-habituating chemosensory responses,
especially flehmen responses, from male elephants. These responses occur
prior to, and are an integral part of, mating. Using bioassay-guided
fractionation, quantitatively dependent on these chemosensory responses,
a specific sex pheromone was isolated and purified by an alternating
series of organic and/or aqueous extractions, column chromatography, gas
chromatography and high-performance liquid chromatography. Using
primarily 1H-proton nuclear magnetic resonance (NMR) spectrometry and
gas chromatography-mass spectrometry (GC-MS) of the urine-derived
pheromone and its dimethyl disulfide derivative, we determined the
structure of the active compound to be (Z)-7-dodecen-1-yl acetate
(Z7-12:Ac). Concentrations of Z7-12:Ac in the female urine increased
from non-detectable during the luteal phase to 0.48 microgram/ml (0.002
mM) early in the follicular phase and to 33.0 micrograms/ml (0.146 mM)
just prior to ovulation. Bioassays with commercially available authentic
synthetic Z7-12:Ac, using 10 Asian male elephants at several locations
in the US, demonstrated quantitatively elevated chemosensory responses
that were robust during successive tests, and several mating-associated
behaviors. Bioassays with Z7-12:Ac with adult male elephants dwelling in
more natural social situations in forest camps in Myanmar revealed some
differing contextual pre-mating behavioral components. The remarkable
convergent evolution of this compound suggests that compounds identified
in mammalian exudates that are also present in pheromone blends of
insects should be re-evaluated as potential mammalian chemosignals.
Rasmussen,
L.E.L., Lee, T.D., Zhang, A., Roelofs, W.L., Daves, G.D., 1997.
Purification, Identification, Concentration and Bioactivity of
(Z)-7-Dodecen-1-yl Acetate: Sex Pheromone of the Female Asian Elephant,
Elephas maximus. Chemical Senses 22, 417-437.
Abstract: In their natural ecosystems, adult male and female Asian
elephants, Elephas maximus, live separately. For several weeks
prior to ovulation, female elephants release a substance in their urine
which elicits a high frequency of non-habituating chemosensory
responses, especially flehmen responses, from male elephants. These
responses occur prior to, and are an integral part of, mating. Using
bioassay-guided fractionation, quantitatively dependent on these
chemosensory responses, a specific sex pheromone was isolated and
purified by an alternating series of organic and/or aqueous extractions,
column chromatography, gas chromatography and high-performance liquid
chromatography. Using primarily 1H-proton nuclear magnetic
resonance (NMR) spectrometry and gas chromatography-mass spectrometry
(GC-MS) of the urine-derived pheromone and its dimethyl disulfide
derivative, we determined the structure of the active compound to be
(Z)-7-dodecen-1-yl acetate (Z7-12:Ac). Concentrations of Z7-12:Ac in the
female urine increased from non-detectable during the luteal phase to
0.48 ug/ml (0.002 mM) early in the follicular phase and to 33.0 ug/ml
(0.146mM) just prior to ovulation. Bioassays with commercially available
authentic synthetic Z7-12:Ac, using 10 Asian male elephants at several
locations in the US, demonstrated quantitatively elevated chemosensory
responses that were robust during successive tests, and several
mating-associated behaviors. Bioassays with Z7-12:Ac with adult male
elephants dwelling in more natural social situations in forest camps in
Myanmar revealed some differing contextual pre-matching behavioral
components. The remarkable convergent evolution of this compound
suggests that compounds identified in mammalian exudates that are also
present in pheromone blends of insects should be re-evaluated as
potential mammalian chemosignals.
Shoshani, J.,
1997. Origins and evolution. In: Eltringham, M.A. (Ed.), The illustrated
encyclopedia of elephants. Salamander Books Ltd., London, pp. 12-29.
Yang, H.,
Golenberg, E.M., Shoshani, J., 1997. Proboscidean DNA from museum and
fossil specimens: an assessment of ancient DNA extraction and
amplification techniques. Biochem Genet 35, 165-179.
Lavergne, A.,
Douzery, E., Stichler, T., Catzeflis, F.M., Springer, M.S., 1996.
Interordinal mammalian relationships: evidence for paenungulate
monophyly is provided by complete mitochondrial 12S rRNA sequences. Mol
Phylogenet Evol 6, 245-158.
Abstract: The complete mitochondrial 12S rRNA sequences of 5 placental
mammals belonging to the 3 orders Sirenia, Proboscidea, and Hyracoidea
are reported together with phylogenetic analyses (distance and
parsimony) of a total of 51 mammalian orthologues. This 12S rRNA
database now includes the 2 extant proboscideans (the African and
Asiatic elephants Loxodonta africana and Elephas maximus), 2 of the 3
extant sirenian genera (the sea cow Dugong dugon and the West Indian
manatee Trichechus manatus), and 2 of the 3 extant hyracoid genera (the
rock and tree hyraxes Procavia capensis and Dendrohyrax dorsalis). The
monophyly of the 3 orders Sirenia, Proboscidea, and Hyracoidea is
supported by all kinds of analysis. There are 23 and 3 diagnostic
substitutions shared by the 2 proboscideans and the 2 hyracoids,
respectively, but none by the 2 sirenians. The 2 proboscideans exhibit
the fastest rates of 12S rRNA evolution among the 11 placental orders
studied. Based on various taxonomic sampling methods among eutherian
orders and marsupial outgroups, the most strongly supported clade in our
comparisons clusters together the 3 orders Sirenia, Proboscidea, and
Hyracoidea in the superorder Paenungulata. Within paenungulates, the
grouping of sirenians and proboscideans within the mirorder Tethytheria
is observed. This branching pattern is supported by all analyses by high
bootstrap percentages (BPs) and decay indices. When only one species is
selected per order or suborder, the taxonomic sampling leads to a
relative variation in bootstrap Paernungulata (92-99%). When each order
or suborder is represented by two species, this relative variation
decreased to 10% for Tethytheria (78-87%) and 3% for Paenungulata
(96-99%). Two nearly exclusive synapomorphies for paenungulates are
identified in the form of one transitional compensatory change, but none
were detected for tethytherians. Such a robust and reliable resolution
of the paenungulate node implies a long history of the common ancestors,
allowing time for synapomorphies to accumulate. This observation
suggests a Late Cretaceous/Early Paleocene origin for the Paenungulata.
Maliarchuk,
B.A., Derevenko, M.V., Lapinskii, A.G., Solovenchuk, L.L., 1996. The use
of the polymerase chain reaction in analyzing ancient DNAs (exemplified
by that of the Enmynveem mammoth). Izv Akad Nauk Ser Biol 6,
681-686.
Abstract: DNA was isolated from the Enmynveem mammoth muscles, and the
control region and cytochrome b gene of the mitochondrial genome were
analyzed by polymerase chain reaction (PCR). The mammoth DNA was
amplified by both the classical PCR (two primer system) and the
single-primer PCR (spPCR) resulting in DNA fragments up to 1600 bp long.
Restriction analysis of the mitochondrial cytochrome b gene was carried
out. Cytochromes b genes in three Elephantidae genera were compared.
Poole, J.,
1996. Coming of Age with Elephants: a Memoir. Hodder and Stoughton, New
York.
Porter, C.A.,
Goodman, M., Stanhope, M.J., 1996. Evidence on mammalian phylogeny from
sequences of exon 28 of the von Willebrand factor gene. Mol Phylogenet
Evol 5, 89-101.
Abstract: Phylogenetic relationships among 27 extant mammalian species
(representing 15 placental orders) were studied using sequences of exon
28 of the gene encoding von Willebrand Factor (vWF), a glycoprotein
which functions in blood clotting. Analysis of sequences coding for vWF
revealed evidence for several subordinal and superordinal groupings, but
the earliest branching sequence of placental mammals was left largely
unresolved. Strong support was found for a monophyletic clade consisting
of elephants, sea cows, hyraxes, aardvarks, and elephant shrews. This
systematic placement of the elephant shrews agrees strongly with two
other molecular data sets (interphotoreceptor retinoid binding protein
and alpha-lens crystallins) and is consistent with analysis of fossil
elephant shrews recently discovered in north Africa. Evidence from vWF
sequences agrees with a number of previous molecular and morphological
studies in providing strong support for the monophyly of both bats and
rodents. The orders Primates, Proboscidea, Carnivora, Perissodactyla,
and Artiodactyla were represented by more than one species which joined
in each case to form a monophyletic order.
Stanhope, M.J.,
Smith, M.R., Waddell, V.G., Porter, C.A., Shivji, M.S., Goodman, M.,
1996. Mammalian evolution and the interphotoreceptor retinoid binding
protein (IRBP)gene: convincing evidence for several superordinal clades.
J Mol Evol 43, 83-92.
Abstract: Phylogenetic relationships of 25 mammalian species
representing 17 of the 18 eutherian orders were examined using DNA
sequences from a 1.2-kb region of the 5' end of exon 1 of the
single-copy nuclear gene known as interphotoreceptor retinoid binding
protein (IRBP). A wide variety of methods of analysis of the DNA
sequence, and of the translated products, all supported a five-order
clade consisting of elephant shrew (Macroscelidea)/aardvark (Tubulidentata)/and
the paenungulates (hyracoids, sirenians, and elephants), with bootstrap
support in all cases of 100%. The Paenungulata was also strongly
supported by these IRBP data. In the majority of analyses this
monophyletic five-order grouping was thefirst branch off the tree after
the Edentata. These results are highly congruent with two other recent
sources of molecular data. Another superordinal grouping, with similar
100% bootstrap support in all of the same wide-ranging types of
analyses, was Artiodactyla/Cetacea. Other superordinal affinities,
suggested by the analyses, but with less convincing support, included a
Perissodactyla/Artiodactyla/Cetacea clade, an Insectivora/Chiroptera
clade, and Glires (an association of rodents and lagomorphs).
Yang, H.,
Golenberg, E.M., Shoshani, J., 1996. Phylogenetic resolution within the
Elephantidae using fossil DNA sequence from the American mastodon
(Mammut americanum) as an outgroup. Proc Natl Acad Sci U S A 93,
1190-1194.
Abstract: DNA was extracted from the extinct American mastodon, the
extinct woolly mammoth, and the modern Asian and African elephants to
test the traditional morphologically based phylogeny within Elephantidae.
Phylogenetic analyses of the aligned sequences of the mitochondrial gene
cytochrome b support a monophyletic Asian elephant-woolly mammoth clade
when the American mastodon is used as an outgroup. Previous molecular
studies were unable to resolve the relationships of the woolly mammoth,
Asian elephant, and African elephant because the sequences appear to
have evolved at heterogeneous rates and inappropriate outgroups were
used for analysis. The results demonstrate the usefulness of fossil
molecular data from appropriate sister taxa for resolving phylogenies of
highly derived or early radiating lineages. Erratum in: Proc Natl Acad
Sci U S A 1996 Apr 30;93(9):4519
Barua, P.,
Bist, S.S., 1995. Changing Patterns in the Distribution and Movement of
Wild Elephants in North Bengal. In: Daniel, J.C. (Ed.), A Week with
Elephants; Proceedings of the International Seminar on Asian Elephants.
Bombay Natural History Society; Oxford University Press, Bombay, India,
pp. 66-84.
Boomker, J.,
Bain, O., Chabaud, A., Kriek, N.P.J., 1995. Stephanofilaria thelazioides
n. sp. (Nematoda: Filariidae) from a hippopotamus and its affinities
with the species parasitic in the African black rhinoceros. Systematic
Parasitology 32, 205-210.
Abstract: Stephanofilaria thelazioides sp. nov. is described and figured
from an ulcerated skin lesion on a hippopotamus Hippopotamus amphibius
from the Kruger National Park, South Africa. This nematode is closely
related to S. dinniki, a parasite of the black rhinoceros Diceros
bicornis in Africa, but differs from it in the number of cuticular
spines surrounding the mouth, the arrangement of the cloacal papillae
and the measurements of the spicules, gubernaculum and microfilariae.
Species of the genus Stephanofilaria possess spines on the head which
have been derived by modification of the sensory papillae. S.
thelazioides is the most primitive species of the genus and has the
least modified arrangement of these papillae, with 6 bifid internal
labial spines, 4 bifid external labial spines and 4 cephalic papillae.
The genus appears to have diversified in various mammals which have in
common a thick skin, such as rhinoceroses, elephants, buffaloes and now
the hippopotamus. It appears to have become adapted secondarily to
domestic bovines, initially in Asia and subsequently in North America.
Hauf, J.,
Baur, A., Chalwatzis, N., Zimmermann, F.K., Joger, U., Lazarev, P.A.,
1995. Selective amplification of a mammoth mitochondrial cytochrome b
fragment using an elephant-specific primer. Curr Genet 27,
486-487.
Jayewardene,
J., 1995. An Overview of Elephant Conservation in Sri Lanka. In: Daniel,
J.C. (Ed.), A Week with Elephants; Proceedings of the International
Seminar on Asian Elephants. Bombay Natural History Society; Oxford
University Press, Bombay, India, pp. 217-224.
Krishnamurthy, V., Wemmer, C. Veterinary Care of Asian Timber Elephants
in India: Historical Accounts and Current Observations. 534. 1995.
Bombay, India, Bombay Natural History Society; Oxford University Press.
Ref Type: Abstract
Krishnamurthy, V., Wemmer, C., 1995. Timber Elephant Management in the
Madras Presidency of India (1844-1947). In: Daniel, J.C. (Ed.), A Week
with Elephants; Proceedings of the International Seminar on Asian
Elephants. Bombay Natural History Society; Oxford University Press,
Bombay, India, pp. 456-472.
Masson, J.M.,
McCarthy, S., 1995. When elephants weep : the emotional lives of
animals. Delacorte, New York.
Mezhzherin,
S.V., Morozov-Leonov, S.I., 1995. The genetic differentiation of
mammalian taxa: their assessment by biochemical genetic markers. Zh
Obshch Biol 56, 71-96.
Abstract: A review of data on genetic differentiation of mammalian taxa
has been made on the basis of estimating the percent of fixed gene
differences (PFD). The results substantiate the existence of evident
differences in the scale of genetic divergence between taxa in different
mammalian orders. Among smaller mammals (marsupials, insectivores,
chiropterans, myomorph and sciuromorph rodents, african mole rats, and
elephant shrews) interspecific differences within a genus involve the
average of 25-40% of investigated loci. At the genetic level the value
is 50-60%, whereas at the familial level the differences are beyond the
resolution capacity of the method (PFD = 60-80%). Orders of larger
mammals can be divided into two subgroups. One of them that includes
carnivores, artiodactylans, and hystricomorph rodents is characterized
by PFD values of 10-14%, 30-50%, and 69-70% at respective levels. The
other subgroup composed of proboscideans, primates, pinnipeds, and
toothed whales, has a low level of
genetic divergence expressed by PFD values of 0-3%, 7-36%, and 50-60% at
species, generic and familial levels, respectively. Insufficiency of
data on baleen whales and Perissodactyla does not allow to cluster them
ultimately with any of these groups. There are three possible, but not
necessarily alternative, causes for the observed differences in genetic
divergence: 1) over-ranking of genera in larger mammals; 2) different
paleontological age of orders; 3) unequal rates of molecular evolution.
Queralt, R.,
Adroer, R., Oliva, R., Winkfein, R.J., Retief, J.D., Dixon, G.H., 1995.
Evolution of protamine P1 genes in mammals. Journal of Molecular
Evolution 40, 601-607.
Abstract: A polymerase chain reaction-based approach was used to amplify
and sequence the protamine genes of the rat, guineapig (order Rodentia),
cat, bear (Carnivora), elephant (Proboscidea), horse (Perissodactyla),
camel, elk, deer, moose and gazelle (Artiodactyla). The predicted amino
acid sequences for these genes, together with previously reported amino
acid sequences of protamine genes of humans, mice, pigs, cattle, fowls,
quails and opossums, resulted in a data set of 25 P1 genes and 30 P1
amino acid sequences. A bootstrapped DNA parsimony tree of the set of
protamine sequences was constructed. The results showed that protamines
were amongst the most rapidly diverging proteins studied. In spite of
the large differences, there were conserved motifs that were also common
to birds. The C-terminus appeared to be the most variable region. The
molecular evolution of P1 genes was in agreement with the expected
species evolution.
Wemmer, C.,
1995. Gaonbura Sahib - A.J.W. Milroy of Assam. In: Daniel, J.C. (Ed.), A
Week with Elephants; Proceedings of the International Seminar on Asian
Elephants. Bombay Natural History Society; Oxford University Press,
Bombay, India, pp. 483-496.
Zhao, X.,
Vyas, K., Nguyen, B.D., Rajarathnam, K., La Mar, G.N., Li, T., Phillips,
G.N., Jr., Eich, R.F., Olson, J.S., Ling, J., 1995. A double mutant of
sperm whale myoglobin mimics the structure and function of elephant
myoglobin. J Biol Chem 270, 20763-20764.
Abstract: The functional, spectral, and structural properties of
elephant myoglobin and the L29F/H64Q mutant of sperm whale myoglobin
have been compared in detail by conventional kinetic techniques,
infrared and resonance Raman spectroscopy, 1H NMR, and x-ray
crystallography. There is a striking correspondence between the
properties of the naturally occurring elephant protein and those of the
sperm whale double mutant, both of which are quite distinct from those
of native sperm whale myoglobin and the single H64Q mutant. These
results and the recent crystal structure determination by Bisig et al. (Bisig,
D. A., Di Iorio, E. E., Diederichs, K., Winterhalter, K. H., and Piontek,
K. (1995) J. Biol. Chem. 270, 20754-20762) confirm that a Phe residue is
present at position 29 (B10) in elephant myoglobin, and not a Leu
residue as is reported in the published amino acid sequence. The single
Gln64(E7) substitution lowers oxygen affinity approximately 5-fold and
increases the rate of autooxidation 3-fold. These unfavorable effects
are reversed by the Phe29(B10) replacement in both elephant myoglobin
and the sperm whale double mutant. The latter, genetically engineered
protein was originally constructed to be a blood substitute prototype
with moderately low O2 affinity, large rate constants, and increased
resistance to autooxidation. Thus, the same distal pocket combination
that we designed rationally on the basis of proposed mechanisms for
ligand binding and autooxidation is also found in nature.
Georgiadis,
N., Bischof, L., Templeton, A., Patton, J., Karesh, W., Western, D.,
1994. Structure and history of African elephant populations: I. Eastern
and southern Africa. J Hered 85, 100-104.
Abstract: Patterns of restriction site variation within mitochondrial
DNA (mtDNA) of 270 individuals were used to examine the current
structure of savanna elephant populations and to infer historical
patterns of gene flow across eastern and southern Africa. Elephants have
a complex population structure characterized by marked subdivision at
the continental level (Fst = 0.39; 95% confidence interval 0.19-0.58),
and isolation by distance at the regional level. However,
phylogeographic analysis revealed evidence of protracted gene flow
across the continent. First, one relatively derived haplotype was found
at all sampling locations. Second, haplotypes representing exceptionally
divergent (up to 8.3%) mitochondrial clades were found to coexist at
distant (> 2,000 km) sampling locations. In the few other species
characterized by sympatric individuals bearing such divergent haplotypes,
all such individuals were found to coexist within limited geographical
regions. Accordingly, pronounced mitochondrial divergence within
populations is often attributed to ancestral isolation in allopatry,
followed by secondary contact. The patterns within elephants do not
accord with ancestral isolation in allopatry. Given the exceptional
mobility of elephants, a geographical barrier is unlikely to have
obstructed gene flow between regions for long enough to produce the
observed mitochondrial divergence. Rather, the patterns are consistent
with the more parsimonious hypothesis, based on neutral coalescent
theory, that gene flow has maintained a sufficiently large effective
population size (> 50,000 females) for representatives of clades that
diverged at least 4 million years ago to have persisted by chance within
a population that was subdivided, but not strictly isolated in allopatry.
Hagelberg,
E., Thomas, M.G., Cook, C.E.Jr., Sher, A.V., Baryshnikov, G.F., Lister,
A.M., 1994. DNA from ancient mammoth bones. Nature 370, 333-334.
Hart, L.A.,
1994. The Asian elephants-driver partnership: the drivers'perspective.
Applied Animal Behaviour Science 40, 297-312.
Hoss, M.,
Paabo, S., Vereshchagin, N.K., 1994. Mammoth DNA sequences. Nature 370,
333.
Jayewardene,
J., 1994. The Elephant in Sri Lanka. WHT Publications Ltd., Colombo, Sri
Lanka.
Armbrusters,
P., Lande, R., 1993. A population viability analysis for African
elephant (Loxodonta africana): How big should reserves be?
Conservation Biology 7, 602-610.
Abstract: We present an age-structured, density-dependent model of
elephant population dynamics in a fluctuating environment drawing
primarily upon the life history parameters obtained from studies in
semi-arid land at Tsavo National Park, Kenya. Density regulation occurs
by changes in the age of first reproduction and calving interval. We
model environmental stochasticity with drought events affecting sex- and
age-specific survivorships. Results indicate a maximum population growth
rate of 3% per year and an equilibrium elephant density of 3.1/square
mile. Analysis of the demographic results and their sensitivity to
changes in juvenile survivorship and drought frequencies, supported by
genetic considerations, suggests that in semi-arid regions a minimum
reserve size of 1000 square mile is necessary to attain a 99%
probability of population persistence for 1000 years. The effect of
age-independent culling on population viability is also analyzed.
Garutt, V.E.,
Aver'ianov, A.O., Vartanian, S.L., 1993. The systematic position of the
holocene population of the mammoth, Mammuthus primigenius (Blumenbach,
1799), of the Vrangel Island (Northeast Siberia). Dokl Akad Nauk 332,
799-801.
Ma, D.P.,
Zharkikh, A., Graur, D., VandeBerg, J.L., Li, W.H., 1993. Structure and
evolution of opossum, guinea pig, and porcupine cytochrome b genes. J
Mol Evol 36, 327-334.
Abstract: We have sequenced the mitochondrial cytochrome b gene from the
guinea pig, the African porcupine, and a South American opossum. A
phylogenetic analysis, which includes 22 eutherian and four other
vertebrate cytochrome b sequences, indicates that the guinea pig and the
porcupine constitute a natural clade (Hystricomorpha) that is not a
sister group to the clade of mice and rats (Myomorpha). Therefore, the
hypothesis that the Rodentia is paraphyletic receives additional
support. The artiodactyls, the perissodactyls, and the cetaceans form a
group that is separated from the primates and the rodents. The 26
sequences are used to study the structure/function relationships in
cytochrome b, whose function is electron transport. Most of the amino
acid residues involved in the two reaction centers are well conserved in
evolution. The four histidines that are believed to ligate the two hemes
are invariant among the 26 sequences, but their nearby residues are not
well conserved in
evolution. The eight transmembrane domains represent some of the most
divergent regions in the cytochrome b sequence. The rate of
nonsynonymous substitution is considerably faster in the human and
elephant lineages than in other eutherian lineages; the faster rate
might be due to coevolution between cytochrome b and cytochrome c.
1992.
Elephants. Majestic creatures of the wild. Rodale Press, Emmaus,
Pennsylvania.
Karunakaran,
R., 1992. The Riddle of Ganesha. Book Quest, Bombay, India.
Schaedler,
J.M., Krook, L., Wootton, J.A., Hover, B., Brodsky, B., Naresh, M.D.,
Gillette, D.D., Madsen, D.B., Horne, R.H., Minor, R.R., 1992. Studies of
collagen in bone and dentin matrix of a Columbian mammoth (late
Pleistocene) of central Utah. Matrix 12, 297-307.
Abstract: A Columbian mammoth, Mammuthus columbi, was excavated at an
elevation of 9000 feet in Huntington Canyon, Emery County, Utah.
Radiocarbon dates on the skeleton indicated death approximately 11,200
years ago. The skeleton was removed from postglacial, Late Quaternary,
lake sediments deposited as glacial runoff approximately 9500 years ago.
The bones and teeth were especially well preserved in a saturated lake
bed. After excavation the bones and teeth were preserved by controlled
desiccation, without hardeners, over a period of 9 months.
Microradiography, light and electron microscopy, medium and high angle
X-ray diffraction, amino acid analysis and cyanogen bromide peptide
mapping were undertaken to evaluate the packing, organization, and
preservation of collagen in bone and dentin of this mammoth.
Microradiography and light microscopy showed that the bone consisted of
especially well preserved compact and trabecular bone, and electron
microscopy of demineralized bone and tusk showed that the matrix
consisted of lamellae of densely packed cylindrical collagen fibrils.
Cell remnants with intact nuclei, with or without a nucleolus, as well
as variable lengths of plasma membrane were occasionally present on the
surface of bony trabecula. Remnants of odontoblast processes were
present in some dentin tubules. High and low angle X-ray diffraction
demonstrated that the demineralized matrix contained native collagen
molecules and amino acid analysis showed that the composition was
comparable to that of type I collagen. Cyanogen bromide peptide mapping
indicated that the major peptides of type I collagen were present and
had the same electrophoretic mobility as that of type I collagen of
demineralized Asian elephant bone and rat tail tendon. Abstract
truncated at 250 words.
Wylie, K.C.,
1992. Elephants used as war machines. In: Shoshani, J. (Ed.), Elephants.
Majestic creatures of the wild. Rodale Press, Emmaus, Pennsylvania, pp.
146-148.
Haynes, G.,
1991. Mammoths, mastodonts, and elephants : biology, behavior, and the
fossil record. Cambridge University Pres, Cambridge ; New York.
Irwin, D.M.,
Kocher, T.D., Wilson, A.C., 1991. Evolution of the cytochrome b gene of
mammals. J Mol Evol 32, 128-144.
Abstract: With the polymerase chain reaction (PCR) and versatile primers
that amplify the whole cytochrome b gene (approximately 1140 bp), we
obtained 17 complete gene sequences representing three orders of hoofed
mammals (ungulates) and dolphins (cetaceans). The fossil record of some
ungulate lineages allowed estimation of the evolutionary rates for
various components of the cytochrome b DNA and amino acid sequences. The
relative rates of substitution at first, second, and third positions
within codons are in the ratio 10 to 1 to at least 33. For deep
divergences (greater than 5 million years) it appears that both
replacements and silent transversions in this mitochondrial gene can be
used for phylogenetic inference. Phylogenetic findings include the
association of (1) cetaceans, artiodactyls, and perissodactyls to the
exclusion of elephants and humans, (2) pronghorn and fallow deer to the
exclusion of bovids (i.e., cow, sheep, and goat), (3) sheep and goat to
the exclusion of other pecorans (i.e., cow, giraffe, deer, and
pronghorn), and (4) advanced ruminants to the exclusion of the
chevrotain and other artiodactyls. Comparisons of these cytochrome b
sequences support current structure-function models for this
membrane-spanning protein. That part of the outer surface which includes
the Qo redox center is more constrained than the remainder of the
molecule, namely, the transmembrane segments and the surface that
protrudes into the mitochondrial matrix. Many of the amino acid
replacements within the transmembrane segments are exchanges between
hydrophobic residues (especially leucine, isoleucine, and valine).
Replacement changes at first and second positions of codons approximate
a negative binomial distribution, similar to other protein-coding
sequences. At four-fold degenerate positions of codons, the nucleotide
substitutions approximate a Poisson distribution, implying that the
underlying mutational spectrum is random with respect to position.
Norton, B.,
1991. The African elephant :last days of Eden. Voyageur Press,
Stillwater, MN, U.S.A.
Nowak, R.M.,
1991. Order Proboscidea. Walker's Mammals of the World. The Johns
Hopkins University Press, Baltimore, pp. 1277-1286.
Sondaar,
P.Y., 1991. Island mammals of the past. Sci Prog 75, 249-264.
Abstract: The effect of insularity on mammal evolution is approached by
considering endemic fossil mammals of islands in the Mediterranean. It
is shown that in general the same mammals will arrive on the islands by
sweepstake dispersal. Among the large mammals this includes elephants,
hippopotamids and deer: all mammals known for their good swimming
ability. The evolutionary changes these mammals underwent follow
parallel patterns on different islands and can be explained as an
adaptational process to an island environment lacking large carnivores.
Altevogt, R.,
Thenius, E., Kurt, F., Grzimek, B., 1990. Proboscideans. Grzimek's
Encyclopedia. McGraw-Hill, Inc., pp. 460-520.
Fischer,
M.S., 1990. The unique ear of elephants and manatees (Mammalia): A
phylogenetic paradox. C. R. Acad. Sci. Ser. III Sci. Vie 311,
157-162.
Rasmussen,
D.T., Gagnon, M., Simons, E.L., 1990. Taxeopody in the carpus and tarsus
of Oligocene Pliohyracidae (Mammalia:Hyracoidea) and the phyletic
position of hyraxes. Proc Natl Acad Sci U S A 87, 4688-4691.
Abstract: Recent hyracoids and elephants share a taxeopode arrangement
of tarsal and carpal bones, a condition in which bones are aligned with
minimal interlocking between adjacent elements. Taxeopody has often been
interpreted as a synapomorphy reflecting a close phyletic link between
Hyracoidea and Proboscidea, but recently it has been suggested [Fischer,
M. S. (1986) Cour. Forschungsinst. Senckenberg 84, 1-132] that hyracoid
taxeopody is an independent acquisition resulting from selection
favoring increased midcarpal and midtarsal rotation and that Hyracoidea
is actually allied with Perissodactyla. As a test of this hypothesis,
isolated carpal and tarsal bones of primitive Oligocene hyracoids from
the Fayum, Egypt, have been examined to determine whether these indicate
a taxeopode or diplarthral carpus and tarsus. Four complete astragali
from the Fayum, representing at least three taxa, show a single,
slightly convex articular surface on the head for articulation with the
navicular and lack a facet for the cuboid. Two complete magna
representing two species have a single proximal facet for articulation
with the lunar, and they lack a facet for the scaphoid. Thus, both the
carpus and tarsus of Fayum hyracoids are taxeopode. Taxeopody in
hyracoids cannot be attributed to selection for carpal and tarsal
rotation in climbers because the Oligocene, Miocene, and Recent species
show great diversity in body size and probably locomotor
specializations, despite relative uniformity of structure in the carpus
and tarsus. The shared taxeopody of hyracoids and proboscideans, along
with other osteological characters and similarities in hemoglobin, eye
lens proteins, and other molecules, all suggest that Hyracoidea belongs
within Paenungulata.
Yu, L.P., La
Mar, G.N., Mizukami, H., 1990. Rearrangement of the distal pocket
accompanying E7 His----Gln substitution in elephant carbonmonoxy- and
oxymyoglobin: 1H NMR identification of a new aromatic residue
in the heme pocket. Biochemistry 29, 2578-2585.
Abstract: Two-dimensional 1H NMR methods have been used to assign side-
chain resonances for the residues in the distal heme pocket of elephant
carbonmonoxymyoglobin (MbCO) and oxymyoglobin (MbO2). It is shown that,
while the other residues in the heme pocket are minimally perturbed, the
Phe CD4 residue in elephant MbCO and MbO2 resonates considerably upfield
compared to the corresponding residue in sperm whale MbCO. The new NOE
connectivities to Val E11 and heme-induced ring current calculations
indicate that Phe CD4 has been inserted into the distal heme pocket by
reorienting the aromatic side chain and moving the CD corner closer to
the heme. The C zeta H proton of the Phe CD4 was found to move toward
the iron of the heme by approximately 4 A relative to the position of
sperm whale MbCO, requiring minimally a 3-A movement of the CD helical
backbone. The significantly altered distal conformation in elephant
myoglobin, rather than the single distal E7 substitution, forms a
plausible basis for its altered functional properties of lower
autoxidation rate, higher redox potential, and increased affinity for CO
ligand. These results demonstrate that one-to-one interpretation of
amino acid residue substitution (E7 His----Gln) is oversimplified and
that conformational changes of substituted proteins which are not
readily predicted have to be considered for interpretation of their
functional properties
Chong, T.S.,
Ohta, H., Nakashima, Y., Iida, T., Saisho, H., 1989. ESR dating of
elephant teeth and radiation dose rate estimation in soil. Int J Rad
Appl Instrum [A] 40, 1199-1202.
Abstract: Chemical analysis of 238U, 232Th and 40K in the dentine as
well as enamel of elephant tooth fossil has been carried out in order to
estimate the internal absorbed dose rate of the specimens, which was
estimated to be (39 +/- 4) mrad/y on the assumption of early uptake
model of radionuclides. The external radiation dose rate in the soil
including the contribution from cosmic rays was also estimated to be
(175 +/- 18) mrad/y with the help of gamma-ray spectroscopic techniques
of the soil samples in which the specimens were buried. The 60Co
gamma-ray equivalent accumulated dose of (2 +/- 0.2) x 10(4) rad for the
tooth enamel gave "ESR age" of (9 +/- 2) x 10(4) y, which falls in the
geologically estimated range between 3 x 10(4) and 30 x 10(4) y before
the present.
Sukumar, R.,
1989. The historical background. The Asian Elephant: Ecology and
Management. Cambridge University Press, Cambridge, pp. 1-9.
Hallett,
H.S., 1988. A Thousand Miles on an Elephant in the Shan States. White
Lotus Co., Ltd., Bangkok, Thailand.
Abstract: Note: This book, first published in 1890, resulted from
Hallett's thorough fact-finding trip through northern Thailandin 1876 in
search of the best route for a railway by which British goods would be
transported from Burma to Thailand. It presents an excellent oerview of
the topography, economy, peoples and customs, legends and local
histories of nothern Thailand in the late 19th century.
Moss, C.,
1988. Elephant memories. Fawcett Columbine (Ballantine), New York.
Terkel, A.S.,
1988. 1987 -- the year of the elephant in Ramat-Gan. International Zoo
News 35, 13-18.
1986. New
species of bacteria in the genus Kurthia--Kurthia sibirica sp. nov.
Mikrobiologiia 55, 831-835.
Abstract: Six aerobic gram-positive nonspore-forming bacterial strains
belonging to the Kurthia genus were isolated from the Magadan (Susuman)
mammoth found in the permafrost of the East Siberia. The strains are a
phenotypically homogeneous group different from the two known species
(K. zopfii and K. gibsonii) in requiring more vitamins, the absence of
growth in a medium with 7% NaCl, and a low level of DNA-DNA
hybridization (not more than 45%). Moreover, the strains differ from K.
zopfii in the synthesis of a yellow pigment, the activity of
phosphatase, and the absence of coccoid forms; the bacteria differ from
K. gibsonii in the absence of growth at a temperature above 40 degrees
C. The organisms are referred to as Kurthia sibirica sp. nov. The type
strain 13-2 has been deposited in the All-Union Collection of
Microorganisms as strain VKB B-1549.
Kleinschmidt,
T., Czelusniak, J., Goodman, M., Braunitzer, G., 1986. Paenungulata: a
comparison of the hemoglobin sequences from elephant, hyrax, and
manatee. Molecular Biology and Evolution 3, 427-435.
Abstract: Inspection of the amino acid differences among hemoglobin
sequences of a wide range of mammalian species suggested that at alpha
19, alpha 110, alpha 111, beta 23, beta 44, and beta 56, synapomorphies
group manatee (Trichechus inungius, Sirenia), Indian and African
elephant (Elephas maximus and Loxodonta africana, Proboscidea), and rock
hyrax (Procavia habessinica, Hyracoidea) into a monophyletic clade.
Results obtained by parsimony analysis provide evidence for this
grouping--and thus support for the genealogical validity of Simpson's
superorder Paenungulata, which contains as the extant orders
Proboscidea, Sirenia, and Hyracoidea. All of the 39 most, or nearly
most, parsimonious of 10,395 trees constructed from a tandemly combined
alpha- and beta-hemoglobin sequence for 103 vertebrate species (of which
79 were mammals from 16 extant orders), depicted Paenungulata as one of
the most anciently separated branches of Eutheria. It was found on
examining thousands of alternative trees that to not group Proboscidea,
Hyracoidea, and Sirenia in a monophyletic clade required at least four
additional substitutions.
Mariappa, D.,
1986. Anatomy and Histology of the Indian Elephant. Indira Publishing
House, Oak Park, MI.
Abstract: This book deals with all aspects of gross anatomy of the
Indian elephant. The chapter on histology covers 35 organs. Apart from
detailed information on the anatomy and histology of the Indian
elephant, the book provides information on many other species of mammals
to cater to the needs of veterinarians and comparative anatomists.
contemporary thoughts on phylogeny of elephants are also discussed in
the introduction.
Yu, N.T.,
Thompson, H.M., Mizukami, H., Gersonde, K., 1986. The cobalt-nitrosyl
stretching vibration as a sensitive resonance Raman probe for distal
histidine-nitrosyl interaction in monomeric hemoglobins. Eur. J Biochem.
159, 129-132.
Abstract: The Co-NO stretching vibration has been assigned in the
resonance Raman spectra of various cobalt-substituted monomeric
hemoglobins by employing isotope-labeling of nitrosyl (14N16O, 15N16O,
14N18O). Monomeric hemoglobins with a distal histidine (sperm whale
myoglobin and leghemoglobin) exhibit this vibration at 573-575 cm-1,
whereas hemoglobins without distal histidine (elephant myoglobin and
insect hemoglobin from Chironomus thummi thummi, CTT III) show this
vibration in the range of 553-558 cm- 1. The Fe-NO stretching vibration
which occurs in the range of 554-556 cm-1 does not reflect the distal
histidine-ligand interaction. Therefore, the Co-NO moiety which is
isoelectronic with the Fe-O2 moiety is a good monitor for distal effects
on the exogenous ligand of hemoglobins, especially due to the fact that
in hemoglobins with distal histidine the Fe-O2 stretching vibration
(567-572 cm-1) is similar to the Co-NO stretching vibration
Johnson,
P.H., Olson, C.B., Goodman, M., 1985. Isolation and characterization of
deoxyribonucleic acid from tissue of the woolly mammoth, Mammuthus
primigenius. Comp Biochem Physiol B 81, 1045-1051.
Abstract: DNA was isolated from tissue samples of several mammoth
specimens, radiocarbon dated between 10,000 and 53,000 years old. The
DNA was purified by chromatography on hydroxyapatite at 60 degrees C and
was characterized as a heterogeneous population of fragments ranging in
size from 3000 to 200 base pairs. Thermal denaturation analysis
demonstrated that approximately 25% of the DNA had a base composition
similar to Asian elephant DNA calculated as 36% G + C. Preliminary
analysis by nucleic acid hybridization indicated that only a small
fraction of DNA isolated from mammoth tissue (2-5%) was homologous to
DNA of Asian elephant, a close living relative of the mammoth. Our
results provide the first definitive isolation and characterization of
DNA from ancient tissue and suggest a purification strategy that will
lead to preparations of DNA from mammoth tissue significantly enriched
in elephant-related DNA sequences.
Douglas-Hamilton, I., 1984. African elephant. In: Mason, I.L. (Ed.),
Evolution of domesticated animals. Longman, London, pp. 193-198.
Mikhailov,
M.I., Kuznetsov, S.V., Zhdanov, V.M., 1984. Electron microscopy of the
intestinal content of a mammoth. The Lancet 2, 111-112.
Olivier,
R.C.D., 1984. Asian elephant. In: Mason, I.L. (Ed.), Evolution of
domesticated animals. Longman, London, pp. 185-193.
Baker,
C.M.A., Manwell, C., 1983. Man and elephant. The "dare theory" of
domestication and the origin of breeds. Zeit. Tierzucht. Zuchtungscbiol.
100, 55-75.
Gibbs, S.J.,
Heller, R.M., Sloan, M., James, A.E., Jr., 1983. External root
resorption in mastodon molar. Oral Surg Oral Med Oral Pathol 55,
542.
Kleinschmidt,
T., Braunitzer, G., 1983. The primary structure of hemoglobins of the
rock hyrax (Procavia habessinica, Hyracooidea): insertion of
glutamine in the alpha chains. Hoppe. Seylers. Z. Physiol. Chem. 364,
1303-1313.
Abstract: The chromatography of the hemoglobin of the rock hyrax
(Procavia habessinica) gives two components (73% HbI and 27% HbII). The
amino-acid analysis and the sequences of the globin chains elucidated
with the phenylthiohydantoin method, did not show any differences
between the alpha I and alpha II or beta I and beta II chains,
respectively. The different chromatographical behaviour cannot be
explained. After chain separation by chromatography on CM-52 cellulose,
all four primary structures were elucidated automatically in a
sequenator on the chains and the tryptic peptides. In 20% of the beta I
chains the N-terminal valine was blocked by acetyl. The alignment was
performed by homology with the chains of human adult hemoglobin. The
alpha chain of the rock hyrax has 142 amino-acid residues, i.e. one
residue more than normal mammalian alpha chains, caused by an insertion
of glutamine in the GH region supposed between positions 115 and 116. A
comparison of human and hyrax hemoglobins shows an exchange of 21
amino-acid residues in the alpha chains and of 24 in the beta chains.
Some substitutions in alpha 1 beta 1 contacts and in the surrounding of
the heme are not supposed to effect the function of the hemoglobin. The
phylogenetic relationship between the rock hyrax and the Indian elephant
(Elephas maximus) on the one hand and with some Perissodactyla on the
other, is discussed. Up to now the exchanges of alpha 110(G17)Ala leads
to Ser and beta 56(D7)Gly leads to His have only been found in hyrax and
elephant. This indicates a certain relationship between Hyracoidea and
Proboscidea.
Valente, A.,
1983. Hair structure of the woolly mammoth, Mammuthus primigenius
and the modern elephants, Elephas maximus and Loxodonta
africanus. Journal of Zoology (Lond) 199, 271-274.
Abstract: The structure of overhairs from a Wooly mammoth, Mammuthus
primigenius, 10-13 thousand years old,is compared with that of its
living relatives, Elephas maximus and Loxodonta africana.
The hair profile, cross-sectional appearance, wholemount and cuticular
scale cast of the hairs of the three species were examined and a
selected array of photographs representing the hair structure of each
species is presented. In general there is little variation between the
three species in the gross structure of the overhairs.
Eltringham,
S.K., 1982. Elephants. Blandfort Books,Ltd., United Kingdom.
De Jong,
W.W., Zweers, A., Goodman, M., 1981. Relationship of aardvark to
elephants, hyraxes and sea cows from alpha-crystallin sequences. Nature
292, 538-540.
Romero-Herrera, A.E., Goodman, M., Dene, H., Bartnicki, D.E., Mizukami,
H., 1981. An exceptional amino acid replacement on the distal side of
the iron atom in proboscidean myoglobin. Journal of Molecular Evolution
17, 140-147.
Abstract: Amino acid sequence determination of elephant myoglobin
revealed the presence of the unusual substitution E7 His -- Gln.
Stereochemical analyses suggest that the most suitable residue which can
functional substitute for His at this position in vertebrate globins in
Gln. Physiological studies imply that the slower rate of autooxidation
of elephant is the result of this substitution which may confer some
selective advantage on the species. Comparative sequence data of
paenungulate myoglobins suggest that the His -- Gln mutation probably
occurred in an ancestor of Elephantinae.
Barnhart,
M.I., Barmatoski, S.P., Goodman, M., Romero-Herrera, A.E., Lande, M.A.,
Birk, D.E., Shoshani, J., Prychodko, W., Lerman, E.J., Mikhelson, V.M.,
1980. Tissue vestiges of an ancient Magadan mammoth calf. Scan Electron
Microsc (Pt 2), 163-170.
Dene, H.,
Goodman, M., Romero-Herrera, A.E., 1980. The amino acid sequence of
elephant (Elephas maximus) myoglobin and the phylogeny of the
Proboscidae. Proc. Roy. Soc. Lond. [B] Biol. Sci. 207, 111-127.
Abstract: The complete amino acid sequence of skeletal myoglobin from
the Asian elephant (Elephas maximus) is reported. The functional
significance of variations seen when this sequence is compared with that
of sperm whale myoglobin is explored in the light of the
crystallographic model available for the latter molecule. The
phylogenetic implications of the elephant myoglobin amino acid sequence
are evaluated by using the maximum parsimony technique. A similar
analysis is also presented which incorporates all of the proteins
sequenced from the elephant. These results are discussed with respect
to current views on proboscidean phylogeny.
Johnson,
D.L., 1980. Problems in the Land Vertebrate Zoogeography of Certain
Islands and the Swimming Powers of Elephants. Journal of Biogeography 7,
383-398.
Abstract: The presence of fossil elephants on certain islands off
California, in the Mediterranean, in Indonesia, and off China has led to
two widely accepted assumptions: (1) that elephants, being poor
swimmers, could not have swum to the islands and therefore must have
walked to them, which indicates that (2) land bridges once joined the
islands to the mainland. These two assumptions have profoundly
influenced various insular biogeographic and geologic reconstructions on
and around these islands. New evidence, however, shows unequivocally
that living elephants are excellent distance swimmers. They swim in a
lunging, porpoise-like fashion while using their trunk as a snorkel.
Elephant swimming speeds have been measured up to 2.70 km/h, and maximum
distances estimated at 48 km. Their chief motives for swimming seem to
be that they can see the islands and smell food on them. Because
elephants are excellent distance swimmers, we must re-appraise the
origin of land vertebrates on all the islands that held elephants, as
well as reappraise the geologic reconstructions that assumed land
bridges once connected these islands to the mainland.
Prager, E.M.,
Wilson, A.C., Lowenstein, J.M., Sarich, V.M., 1980. Mammoth albumin.
Science 209, 287-289.
Abstract: Serum albumin was detected immunologically in muscle from a
mammoth that died about 40,000 years ago. Rabbits injected with ground
mammoth muscle produced antibodies that react strongly with elephant
albumin, weakly with sea cow albumin, and still more weakly or not at
all with other mammalian albumins. Since elephant albumin elicited
antibodies with the same specificity, some of the surviving mammoth
albumin molecules evidently have antigenic sites identical to those on
native elephant albumin. Much of the mammoth albumin has, however,
undergone postmortem change. The small amount of soluble albumin
extractable from mammoth muscle is heterogeneous in size, charge, and
antigenic properties.
Gillespie,
J.M., 1979. Mammoth hair: stability of alpha-keratin structure and
constituent proteins. Science 170, 1100-1102.
Kingdon, J.,
1979. East African mammals. An atlas of evolution in Africa III. Large
mammals. Academic Press, London.
Kirkwood,
T.B., Holliday, R., 1979. The evolution of aging and longevity. Proc R
Soc Lond B Biol Sci 205, 531-546.
Abstract: Aging is not adaptive since it reduces reproductive potential,
and the argument that it evolved to provide offspring with living space
is hard to sustain for most species. An alternative theory is based on
the recognition that the force of natural selection declines with age,
since in most environments individuals die from predation, disease or
starvation. Aging could therefore be the combined result of
late-expressed deleterious genes which are beyond the reach of effective
negative selection. However, this argument is circular, since the
concept of 'late expression' itself implies the prior existence of adult
age-related physiological processes. Organisms that do not age are
essentially in a steady state in which chronologically young and old
individuals are physiologically the same. In this situation the
synthesis of macromolecules must be sufficiently accurate to prevent
error feedback and the development of lethal 'error catastrophes'. This
involves the expenditure of energy, which is required for both kinetic
proof-reading and other accuracy promoting devices. It may be
selectively advantageous for higher organisms to adopt an energy saving
strategy of reduced accuracy in somatic cells to accelerate development
and reproduction, but the consequence will be eventual deterioration and
death. This 'disposable soma' theory of the evolution of aging also
proposes that a high level of accuracy is maintained in immortal germ
line cells, or alternatively, that any defective germ cells are
eliminated. The evolution of an increase in longevity in mammals may be
due to a concomitant reduction in the rates of growth and reproduction
and an increase in the accuracy of synthesis of macromolecules. The
theory can be tested by measuring accuracy in germ line and somatic
cells and also by comparing somatic cells from mammals with different
longevities.
Kreps, E.M.,
Chirkovskaia, E.V., Pomazanskaia, L.F., Avrova, N.F., Levitina, M.V.,
1979. Brain lipids of a mammoth, Elephas primigenius, which died more
than 40,000 years ago. Zh Evol Biokhim Fiziol 15, 227-238.
Abstract: Studies have been made on the brain lipids of the 6--7-month
mammoth which remained in the eternal ice for more than 40.000 years.
Thin layer chromatography of chloroformmethanol extract of the brain
lipids shows that all glycerophospholipids in the brain were destroyed.
On the contrary, sphingophospholipid sphingomyelin yielded the evident
spot which was identified by specific reactions and by comparison with
sphingomyelin from the brain of rat. Sphingomyelin content was
evaluated. Using gas-liquid chromatography, fatty acid composition of
sphingomyelin was investigated. It was found to be close to that in
contemporary mammals. Other shingolipids -- cerebrosides, sulfatides,
gangliosides -- persisted (probably, only partially) and were studied
quantitatively. Relative content of cerebrosides with normal fatty acids
and hydrooxyacids was determined. Studies were also made on fatty acid
composition of cerebrosides, sulfatides and gangliosides, as well as on
the composition of spingosine bases of gangliosides. Free cholesterol
was found in the brain of the mammoth. Other sterols were not detected.
With respect to quantitative evaluation of the preserved lipids, it
should be mentioned that on the one hand, the brain underwent
dehydration which increased lipid content per a unit of "wet" weight,
whereas on the other one lipids were partially degraded, this process
decreasing their content.
Subbotin,
V.M., Tum, Iu.V., 1978. Results of a microscopic study of several
remains of the internal organs of Shandrin's mammoth. Arkh Anat Gistol
Embriol 74, 85-89.
Abstract: The survived portion of an organ which topographically can be
considered as a part of the lung, as well as a section of muscular
tissue, perhaps that of the heart, has been studied. Under weak systems,
the portion resembles the lung, spaces resembling alveoles, alveolar
ducts and alveolar saccules are seen. "Alveolar" walls are stained dark
grey by different methods; "alveoles" contain yellow granules, ferric
components are not detected in them. The intestinal wall and that of the
large vessel in the mesenteric cavity preserves a fibrillar carcass,
fibrillar ultrastructure corresponding to collagen.
De Jong,
W.W., Gleaves, J.T., Boulter, D., 1977. Evolutionary changes of
alpha-crystallin and the phylogeny of mammalian orders. J Mol Evol 10,
123-135.
Abstract: The sequences of the A chains of the eye lens protein
alpha-crystallin from seventeen mammalian species were compared. They
showed a generally slow rate of evolution, but with marked variations in
different lineages. Most substitutions have occurred in the C-terminal
part of the chain, which probably forms part of the surface of the
alpha-crystallin aggregate. The ancestral sequence method of Dayhoff
revealed interesting indications about the phylogenetic relationships
between the eleven mammalian orders that were represented by the
investigated species. Most evident was the divergence of marsupial and
placental orders. A notable resemblance between the hyrax and elephant
sequences was observed, setting them apart from the ungulates, including
whale. Primates, rodents, lagomorphs, insectivores and tupaiids seem to
derive from a common stem group. These phylogenetic inferences are
discussed in relation to current paleontological and taxonomical
opinions, and compared to evidence from other protein sequence data.
De Jong,
W.W., Nuy-Terwindt, E.C., Versteeg, M., 1977. Primary structures of
alpha crystallin A chains of elephant, whale, hyrax and rhinoceros.
Biochim. Biophys. Acta 491, 573-580.
Abstract: As part of a study of the evolutionary development of the eye
lens protein alpha-crystallin the 173 residue A chain of this protein
has been studied in elephant, whale, hyrax and rhinoceros. The primary
sturctures were inferred mainly from amino acid compositions of peptides
obtained by enzymatic digestions and CNBr cleavage. The positions of
substitutions, as compared to known bovine A chain, were confirmed by
Edman degradation. In accordance with the previously observed slow rate
of evolution of the A chain only a small number of substitutions were
found among these species. Elephant and hyrax share a number of unique
substitutions, strongly indicating a common ancestry of these two
species within the mammalian class.
Hanks, J.,
1977. Comparative aspects of reproduction in the male hyrax and
elephant. In: Calaby, J.H., Tyndale-Biscoe, C.H. (Eds.), Reproduction
and evolution. Australian Academy of Science, pp. 155-164.
Douglas-Hamilton, I., Douglas-Hamilton, O., 1975. Among the elephants.
Viking Press, New York.
Gombe, S.,
Heap, R.B., Sale, J.B., 1975. Endocrinology of pregnancy in the hyrax;
plasma progesterone concentration and erythrocyte metabolism. Proc.
Physiol. Soc. September, 13P-14P.
Heap, R.B.,
Gombe, S., Sale, J.B., 1975. Pregnancy in the hyrax and erthrocyte
metabolism of progesterone. Nature 257, 809-811.
Moss, C.,
1975. Portraits in the wild. University of Chicago Press, Chicago.
Riemann,
G.P., Burridge, M.J., Behymer, D.E., Franti, C.E., 1975. Toxoplasma
gondii antibodies in free-living African mammals. J Wildl Dis 11,
529-533.
Abstract: Twelve species of free-living African mammals from Kenya,
Tanzania, Uganda and Zambia were tested for antibodies to Toxoplasma
gondii using the indirect hemagglutination test. Of 157 animals sampled,
20 (13%) were seropositive. T. gondii antibodies were detected in
Burchell's zebra, (Equus burchelli), hippopotamus (Hippopotamus
amphibius), African elephant (Loxodonta africana), defassa waterbuck
(Kobus defassa), lion (Panthera leo), and rock hyrax (Procavia
capensis), The highest titers were found in elephants, two having titers
of 1:4096 and one of 1:8192. These results are discussed in relation to
the maintenance of T. gondii among African wildlife.
Scullard,
H.H., 1974. The Elephant in the Greek and Roman World. Cornell
University Press, Ithaca, NY.
Fawcett,
D.W., Neaves, W.B., Flores, M.N., 1973. Comparative observations on
intertubular lymphatics and the organization of the interstitial tissue
of the mammalian testis. Biology of Reproduction 9, 500-532.
Maglio, V.J.,
1972. Evolution of mastication in the Elephantidae. Evolution 26,
638-658.
Sikes, S.K.,
1971. The Natural History of the African Elephant. American Elsevier
Publishing Company, Inc., New York.
Aguirre, E.,
1969. Evolutionary history of the elephants. Science, New Series 164,
1366-1376.
Abstract: Elephants which are among the most popular and decorative of
animals, stand as a witness of prehistory, having been a part of the
environment of our ancestors. The dinosaur was not contemporary with
early man, as many films and stories insist, but the mammoth was.
Although prehistoric or extinct elephants are frequently referred to as
mammoths, such a designation is not always correct. The true mammoth is
but one of many species of extinct elephants; furthermore, it belongs to
one of a few genera, which include four or five species that have
affinities with the woolly elephants. These different genera and species
are grouped by zoologists into a family, Elephanttidae. Because this
family originated by the beginning of the Pleistocne period, elephants
can be considered contemporary with man. Anthropologists and
prehistorians have often attempted to establish a chronology of sites of
fossil man through correlations based upon the species of elephants
associated with them but the systematics of the Elephantidae is quite
confused. The documented monograph of Osborn established 10 genera and
some 59 species of elephants; to these Garutt added two more genera.
However many taxonomists have recognized only one genus and no more than
five or six valid species. In the museum collection from most major
sites, there are many samples with dubious identifications and many
intermediate forms labeled either with two names or with a composite or
new name. It has been assumed that many different species have lived
contemporaneously in a single area, as was the case for the sample
excavated in the railway trench of San Paolo, Italy, in the first years
of this century. Explanations of the phylogeny of elephants have had one
feature in common: the patterns for the phyletic trees have agreed with
with the fashionable evolutionary theories of the particular period.
Thus all the trees are dichotomic and linear form 1881 to 1888, fairly
dichotomic form 1888 to 1912 and polyphyletic until 1923. After 1940
dichotomic patterns are again found. A review of the evolutionary
history of the Proboscidae before the appearance of the elephants may
help us to understand the significance of the evolving character in the
latter. For Proboscidae since the Old Tertiary period, two major
characteristics have been defined: the anterior teeth are missing except
for one or two pairs of tusks; and there is an increasing number of rows
of cusps, with every new transversal row appearing behind the other and
elongating the molar teeth.
Hooijer,
D.A., 1967. Indo-Australian insular elephants. Genetica 38,
143-162.
Nirmalan, G.,
Nair, S.G., Simon, K.J., 1967. Hematology of the Indian elephant (Elephas
maximus). Canadian Journal of Physiology and Pharmacology 45,
985-991.
Abstract: Blood samples from 11 baby elephants, 14 tuskers, and 16
females comprising 5 pregnant and 11 nonpregnant nonlactating elephants
(Elephas maximus) were analyzed to assess the hematological
values and the influence of age, sex and pregnancy on these. The results
obtained show that, compared with other mammals, the erythrocyte count
in the blood of elephants is low and the mean corpuscular volume
(m.c.v.), mean corpuscular hemoglobin (m.c.h.), and erythrocyte
sedimentation rate (e.s.r.) are high. The very high values for m.c.v.
and m.c.h. and the low erythrocyte count seen in elephants suggest that
in the evolution of blood through they are more advanced than reptiles
and birds in having eliminated the nuclei from the erythrocytes, they
are still in the primitive state compared with the other mammals
inasmuch as their erythrocytes have not attained the efficiency in the
transportation of blood gasses that results from a reduction in size to
facilitate numerical increase. A low erythrocyte count and packed cell
volume, a high e.s.r., an increase in neutrophils, and a decrease in the
percentage of lymphocytes and eosinophils characterize pregnancy. In
baby elephants there is an increase in the total leucocyte and
lymphocyte counts and a decrease in eosinophils.
Buettner-Janusch, J., Buettner-Janusch, V., Sale, J.B., 1964. Plasma
proteins and haemoglobins of the African elephant and the hyrax. Nature
201, 510-511.
Carrington,
R., 1959. Elephants: A short account of their natural history,
evolution and influence on mankind. Basic Books, Inc., New York.
Carrington,
R., 1957. Mermaids and mastodons. Chalto & Windus, London.
Dolch, E.W.,
Dolch, M.P., 1956. Elephant Stories. Garrard Publishing Company,
Champaign, Illinois.
Abstract: Note: This book is part of a Basic Vocabulary Series
Deraniyagala,
P.E.P., 1955. Some Extinct Elephants, Their Relatives and the Two Living
Species. Ceylon National Museums publication, Government Press, National
Museum, Colombo (Sri Lanka).
Deranyagala,
P.E.P., 1955. Some extinct elephants, their relatives and the two living
species. Ceylon National Museum Publ., Colombo.
Weitz, B.,
1953. Serological relationships of hyrax and elephant. Nature 171,
261.
Morrison-Scott, T.C.S., 1947. A revision of our knowledge of African
elephants' teeth, with notes on Forest and "Pygmy" elephants. Procedings
of the Zoological Society of London 117, 505-527.
Wislocki,
G.B., 1940. The topography of the hypophysis of the elephant, manatee,
and hyrax. Anatomical Record 77, 427-445.
Nilakantha of
Rajamangalam, 1931. The elephant lore of the Hindus. The elephant-sport
(Matanga-lila) of Nilakantha. Translated from original Sanskrit with
introduction, notes and glossary by Franklin Edgerton. Yale University
Press, New Haven.
Goodwin,
G.G., 1925. The first living elephant in America. Journal of Mammalogy 6,
256-263.
Bishop, C.W.,
1921. The elephant and its ivory in ancient China. Journal of the
American Oriental Society 41, 290-306.
1839. The
Elephant (as he exists in a wild state and as he has been made
subservient, in peace and war, to the purposes of man). Harper and
Brothers, New York.
Abstract: Note: This work was originally published by the British
Society for the Diffusion of Useful Knowledge
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