Staying out in the cold: glacial refugia and mitochondrial DNA phylogeography in ancient European brown bears

Abstract

Models for the development of species distribution in Europe typically invoke restriction
in three temperate Mediterranean refugia during glaciations, from where recolonization of
central and northern Europe occurred. The brown bear, Ursus arctos, is one of the taxa from
which this model is derived. Sequence data generated from brown bear fossils show a
complex phylogeographical history for western European populations. Long-term isolation
in separate refugia is not required to explain our data when considering the palaeontological
distribution of brown bears. We propose continuous gene flow across southern Europe,
from which brown bear populations expanded after the last glaciation.