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Zwartewaal, Netherlands

Horn S.,Max Planck Institute for Evolutionary Anthropology | Prost S.,University of Otago | Prost S.,University of California at Berkeley | Prost S.,Swedish Museum of Natural History | And 10 more authors.
Molecular Ecology | Year: 2014

After centuries of human hunting, the Eurasian beaver Castor fiber had disappeared from most of its original range by the end of the 19th century. The surviving relict populations are characterized by both low genetic diversity and strong phylogeographical structure. However, it remains unclear whether these attributes are the result of a human-induced, late Holocene bottleneck or already existed prior to this reduction in range. To investigate genetic diversity in Eurasian beaver populations during the Holocene, we obtained mitochondrial control region DNA sequences from 48 ancient beaver samples and added 152 modern sequences from GenBank. Phylogeographical analyses of the data indicate a differentiation of European beaver populations into three mitochondrial clades. The two main clades occur in western and eastern Europe, respectively, with an early Holocene contact zone in eastern Europe near a present-day contact zone. A divergent and previously unknown clade of beavers from the Danube Basin survived until at least 6000 years ago, but went extinct during the transition to modern times. Finally, we identify a recent decline in effective population size of Eurasian beavers, with a stronger bottleneck signal in the western than in the eastern clade. Our results suggest that the low genetic diversity and the strong phylogeographical structure in recent beavers are artefacts of human hunting-associated population reductions. While beaver populations have been growing rapidly since the late 19th century, genetic diversity within modern beaver populations remains considerably reduced compared to what was present prior to the period of human hunting and habitat reduction. © 2014 John Wiley & Sons Ltd. Source

Lion remains are rare in fossil records and although there are more limb bones, research is done mainly on skulls and mandibles. That's why there is a need to make a greater comparison of limb bones. In this investigation the five long bones, humerus, ulna, radius, femur and tibia, are compared with a skeleton of Panthera leo. The ratios in Panthera leo skeletons appear to be very constant like those from fossil Panthera spelaea, but with some exceptions. It is possible to compare bones from different geographical areas and different chronological periods and there is probably some evidence of adaptation to environment like climate and prey or separating in sub species. Source

Marciszak A.,Wroclaw University | Schouwenburg C.,Dorpsstraat 53
Quaternary International | Year: 2014

This study analyzed size changes in the course of the time among European Middle and Late Pleistocene lions. The general decreasing size as a tendency in cave lion evolution is confirmed. The whole time span of lion presence in Europe was divided into four main periods. The first period covers Middle and late Middle Pleistocene (MIS 19-17 to MIS 7-6) and is characterized by the presence of very large individuals with somewhat primitive morphology. It might be cautiously said that lions in that time were comparatively large throughout the Middle and late Middle Pleistocene. The second period included the last part of the late Middle and the beginning of the Late Pleistocene (MIS 6-5). This period is documented by a mixed presence of large individuals with somewhat primitive features together with smaller, evolutionarily more advanced dentition lions. The third period covers the first part of the last glacial, from MIS 5 to the beginning of MIS 3. For this period, the occurrence of moderate sized specimens with evolutionarily advanced dentition is documented. The last period began with dramatic population decline and genetic variability reduction. It lasted from MIS 3 and 2, and within it size drops sharply. Among moderate sized specimens, very small lions with somewhat lesser posture also appeared. Asian or African affinities as a result of a new migration event for those dwarf lions could not be ruled out. Size decrease showed that Panthera spelaea was a dynamically evolved species. Thus, the size does not seem to be a reliable criterion in determining the age of cave lion findings. The general overview is complicated by the great sexual dimorphism, local evolution and extinction, climatic conditions, and migrations. Size changes in P. spelaea evolution cannot be used as a useful biochronological tool. © 2013 Elsevier Ltd and INQUA. Source

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