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Culture, History, Evolution, and General Interest
(The following 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 2007
1.
Archie E.A., Hollister-Smith J.A., Poole J.H. et al. 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.
2.
Aroch I., King R. and 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.
3.
Asara J.M., Schweitzer M.H., Freimark L.M., Phillips M. and 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
4.
Bates L.A. and 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,
sociallearning 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.
5.
Bicer S. and Reiser P.J. 2007. Variations in apparent mass of mammalian
fast-type myosin light chains correlate with species body size, from
shrew to elephant.Am J Physiol Regul Integr Comp Physiol. 292:
R527-R534.
Abstract: A recent study (Bicer S and Reiser PJ. J Muscle Res Cell Motil
25: 623-633, 2004) suggested considerable variation in the apparent
molecular mass (M(a)), deduced from electrophoretic mobility, in
fast-type myosin light chains (MLCF), especially MLC1F, among mammalian
species. Furthermore, there was an indication that MLC1F M(a) generally
correlates with species body mass, over an approximately 4,000-fold
range in body mass. The results also suggested that M(a) of other
low-molecular-weight myofibrillar proteins is less variable and not as
strongly correlated with body mass among the same species. The objective
of this study was to test the hypotheses that the M(a) of MLCs does, in
fact, vary and correlate with species body mass. The electrophoretic
mobilities of MLCF isoforms from 19 species, varying in size
approximately 500,000-fold, were quantitated. The results confirm that
the M(a) of MLC1F and MLC2F vary significantly among mammals, spanning a
very broad range in body mass; the MLC1F M(a) varies more than that of
other low-molecular-weight myofibrillar proteins; and there is a
significant correlation between species body mass and MLC1F M(a).
Differences in MLC1F M(a) among five species can be accounted for by
differences in the reported amino acid sequence, especially the length
of a common polyalanine region near the NH(2)-terminal actin-binding
site. The possibility that the differences in MLC1F sequence among
mammalian species, in and adjacent to the actin-binding region, are
related to differences in modulation of cross-bridge kinetics in species
with diverse locomotion kinetics is discussed. Department of Oral
Biology, The Ohio State University, 305 West 12th Ave., Columbus, OH
43210-1247, USA.
6.
Binladen J., Gilbert M.T.P. and Willerslev E. 2007. 800,000 year old
mammoth DNA, modern elephant DNA or PCR artefact?Biology Letters 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.
7.
Binladen J., Gilbert M.T. and Willerslev E. 2007.
800,000 year
old mammoth DNA, modern elephant DNA or PCR artefact?Biol Lett 3: 55-56.
Abstract: Comment on: Biol Lett. 2006 Sep 22;2(3):451-4. 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.
8.
Kellogg M.E., Burkett S., Dennis T.R. et al. 2007.
Chromosome
painting in the manatee supports Afrotheria and Paenungulata.BMC
Evolutionary Biology 7.
Abstract: 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.
9.
Kullberg M., Hallström B., Arnason U. and 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.
10.
Murphy W.J., Pringle T.H., Crider T.A., Springer M.S. and Miller W.
2007. Using genomic data to unravel the root of the placental mammal
phylogeny.Genome Research 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.
11.
Orlando L., Pages M., Calvignac S., Hughes S. and 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.
12.
Orlando L., Pagés M., Calvignac S., Hughes S. and Hänni 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: Comment on:Biol Lett. 2006 Sep 22;2(3):451-4. 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.
13. 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. Department of Molecular
Biology and Genetics, Johns Hopkins University School of Medicine,
Baltimore, Maryland 21205, USA. djpan@jhmi.edu
14.
Pardini A.T., O'Brien P.C., Fu B. et al. 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.
15.
Pardini A.T., O'Brien P.C.M., Fu B. et al. 2007.
Chromosome
painting among Proboscidea, Hyracoidea and Sirenia: Support for
Paenungulata (Afrotheria, Mammalia) but not Tethytheria.Proceedings Of
The Royal Society B-Biological Sciences 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.
16.
Rohland N., Malaspinas A.S., Pollack J.L., Slatkin M. and 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.
17.
Sreekumar E., Janki M.B.V., Arathy D.S. et al. 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.
18.
Tabuce R., Marivaux L., Adaci M. et al. 2007.
Early
tertiary mammals from north Africa reinforce the molecular afrotheria
clade.Proc R Soc Lond B 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.
19.
Tabuce R., Marivaux L., Adaci M. et al. 2007.
Early
Tertiary mammals from North Africa reinforce the molecular Afrotheria
clade.Proceedings of the Royal Society B: Biological Sciences, 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. 105-25Myr 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.
20.
Wallis M. 2007. 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 Epub ahead of print.
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.
21.
Wellehan J.F., Johnson A.J., Childress A.L., Harr K.E. and 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.
22.
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.
23.
Cooper D.W. and 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.
24.
Gelvin-Reymiller C., Reuther J.D., Potter B.A. and 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.
25.
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.
26.
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.
27.
Kalmykov N.P. and Mashchenko E.N. 2006. New data on the migration of the
family Elephantidae (Mammalia, Proboscidea) in Eurasia.Dokl Biol Sci
406: 103-105.
28.
Krause J., Dear P.H., Pollack J.L. et al. 2006.
Multiplex
amplification of the mammoth mitochondrial genome and the evolution of
Elephantidae.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.
29.
Larke A. and 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.
30.
Plotnik J.M., de Waal F.B. and Reiss D. 2006. Self-recognition in an
Asian elephant.Proc Natl Acad Sci U S A 103: 17053-1770.
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. Living Links, Yerkes National Primate
Research Center, and Department of Psychology, Emory University, 532
North Kligo Circle, Atlanta, GA 30322, USA.
31.
Poinar H.N., Schwarz C., Qi J. et al. 2006.
Metagenomics
to paleogenomics: large-scale sequencing of mammoth DNA.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.
32.
Poulakakis N., Parmakelis A., Lymberakis P. et al. 2006.
Ancient DNA forces reconsideration of evolutionary history of
Mediterranean pygmy elephantids.Biology Letters 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.
33.
Rogaev E.I., Moliaka Y.K., Malyarchuk B.A. et al. 2006. Complete
mitochondrial genome and phylogeny of Pleistocene mammoth Mammuthus
primigenius.PLoS Biology 4: 1-8.
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 ;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.
34.
Rothschild B.M. and 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.
35.
Rothschild B.M. and Laub R. 2006. Hyperdisease in the late
Pleistocene:validation of an early 20th century
hypothesis.Naturwissenschaften 93: 557-564.
36.
Rubenstein D.R., Sherman P.W. and 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.
37.
Schmitt D., Cartmill M., Griffin T.M., Hanna J.B. and Lemelin P. 2006.
Adaptive value of ambling gaits in primates and other mammals.J Exp Biol
209 (Pt 11): 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.Department of
Biological Anthropology and Anatomy, Duke University, Durham, NC 27710,
USA. daniel_schmitt@baa.mc.duke.edu
38.
Shoshani J., Walter R.C., Abraha M. et al. 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
39.
Shoshani J., Kupsky W.J. and 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.
40.
Uni S., Bain O., Agatsuma T. et al. 2006.
New filarial
nematode from Japanese serows (Naemorhedus crispus: Bovidae) close to
parasites from elephants.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.Department of Medical Zoology, Osaka City University Medical
School, Osaka 545-8585, Japan. uni@med.osaka-cu.ac.jp
41.
Agnew D.W., Hagey L. and Shoshani J. 2005. The elephants of Zoba Gash
Barka, Eritrea: part 4. Cholelithiasis in a wild African elephant
(Loxodonta africana).Journal of Zoo and Wildlife Medicine 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 all excavated mammoth (Mammuthus columbi). Choleliths have been
reported only once in it 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.
42.
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.
43.
Delves P.J. and Roitt I.M. 2005. Vaccines for the control of
reproduction--status in mammals, and aspects of comparative interest.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.
44.
Edwards H.G., Jorge Villar S.E., Nik Hassan N.F. et al. 2005.
Ancient biodeterioration: an FT-Raman spectroscopic study of mammoth and
elephant ivory.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.
45.
Edwards H.G.M., Hassan N.F.N. and 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.
46.
Hambler C., Henderson P.A. and 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.
47.
Kalmykov N.P. and 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.
48.
Konishi S. 2005. Jaws of herbivorous mammals.Clin Calcium 15: 1414-1417.
Abstract: The jaws of herbivorous mammals are characterized by their
large occlusal surface of the molar; high crown of the molar; long
snout; etc. However,
elephants, the biggest herbivorous mammal, have other characteristics.
In the evolutionary trends of proboscidean skulls, concomitant with the
increase in
tusk size comes on the enlargement, antero-posterior shortening, dorso-ventral
elongation of the cranium with increasing cheek teeth size. Naturally,
the jaw follows the same evolutionary trends as the cranium.
49.
Loannidis J.P.A. 2005. Why most published research findings are
false.PLoS Med 2: e124.
50.
Nishihara H., Satta Y., Nikaido M. et al. 2005. A retroposon
analysis of Afrotherian phylogeny.Mol Biol Evol 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.
51.
Palombo M.R. and 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.
52.
Perez-Barberia F.J. and Gordon I.J. 2005. Gregariousness increases brain
size in ungulates.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.
53.
Roca A.L., Georgiadis N. and O'Brien S.J. 2005. Cytonuclear genomic
dissociation in African elephant species.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.
54.
Roca A.L. and O'Brien S.J. 2005. Genomic inferences from Afrotheria and
the evolution of elephants.Current Opinion in Genetics and Development
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.
55.
Roth G. and Dicke U. 2005. Evolution of the brain and
intelligence.TRENDS in Cognitive Sciences 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
56.
Shoshani J. and 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.
57.
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.
58.
Stone J. and 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.
59.
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.
60.
Agatsuma T., Rajapakse R.P., Kuruwita V.Y., Iwagami M. and Rajapakse R.C.
2004. Molecular taxonomic position of the elephant schistosome,
Bivitellobilharzia nairi, newly discovered in Sri Lanka.Parasitology
International 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. Department of Environmental Health Science,
Faculty of Medicine, Kochi Medical School, Kochi 783-8505, Japan.
agatsuma@med.kochi-ms.ac.jp
61.
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
62.
Buchanan K.L. and 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 |