Climatic changes during the Late Pleistocene had major impacts on the populations of many plant and animal species. During this period, humans and large mammals, e.g. brown bear and moose, were subject to analogous phylogeographic pressures and were linked by important ecological processes. However, evidence of human dispersal in northern Eurasia during the Late Pleistocene is scarce. Analysis of large mammals therefore has the potential to shed light on the population processes of humans during this period. We address several unresolved issues regarding the Late Pleistocene demography of brown bears: (a) the putative locations of refugia; (b) the direction of migrations across Eurasia and into North America; and (c) parallels with other mammals, including humans. We present results based on more than 200 complete mitochondrial genome sequences from Eurasian and North-American brown bears. Bayesian phylogenetic analysis revealed that most individuals belong to a very large Holarctic clade. The MRCA of this clade lived ca 40 thousand years ago, most likely in the Altai-Sayan area, a known Late Pleistocene refugium in Asia. We propose several migration scenarios for bears and suggest that brown bears and humans underwent a series of parallel migrations in Eurasia and to North America during the Late Pleistocene. Moreover, both species exhibited a demographic standstill in Beringia before colonizing North America. Synchrony in the timing of past migrations and standstill implies that the ecology of large mammals includes key limiting factors that can enhance our understanding of ancient human movements and on large carnivore conservation.Saarma et al., Parallel migrations in brown bears and humans within Eurasia and into North America during the Late Pleistocene, ConGenomics 2016 abstract.
Sunday, May 22, 2016
Parallel migrations in brown bears and humans within Eurasia
If, as per the abstract below, a major part of the Native American gene pool derives from the Altai-Sayan refugium, then it's likely to be the Ancient North Eurasian (ANE) part, rather than the East Asian part. So I'd say that for now the Altai-Sayan region looks like a pretty good option for the homeland of the ANE people (aka Mal'ta cluster).