Data from: Genomics of end-Pleistocene population replacement in a small mammal

Current species’ distributions at high latitudes are the product of
expansion from glacial refugia into previously uninhabitable areas at the
end of the last glaciation. The traditional view of postglacial
colonization is that southern populations expanded their ranges into
unoccupied northern territories. Recent findings on mitochondrial DNA
(mtDNA) of British small mammals have challenged this simple colonization
scenario by demonstrating a more complex genetic turnover in Britain
during the Pleistocene-Holocene transition where one mtDNA clade of each
species was replaced by another mtDNA clade of the same species. Here, we
provide evidence for one of those small mammals, the bank vole
(Clethrionomys glareolus), that the replacement was genome-wide. Using
more than 10,000 autosomal SNPs we found that similar to mtDNA, bank vole
genomes in Britain form two (north and south) clusters which admix.
Therefore, the genome of the original post-glacial colonists (the northern
cluster) was likely replaced by another wave of migration from a different
continental European population (the southern cluster), and we gained
support for this by modelling with approximate Bayesian computation. This
finding emphasises the importance of analysis of genome-wide diversity
within species under changing climate in creating opportunities for
sophisticated testing of population history scenarios.