Mitochondrial phylogeography and population history of pine martens Martesmartes compared with polecats Mustela putorius

The flora and fauna of Europe are linked by a common biogeographic history, most recently the Pleistocene glaciations that restricted the range of mos t species to southern refugial populations. Changes in population size and migration, as well as selection, have all left a signature on the genetic d ifferentiation. Thus, three paradigms of postglacial recolonization have be en described, inferred from the patterns of DNA differentiation. Yet some s pecies, especially wide-ranging carnivores, exhibit little population struc turing between the proposed refugia, although relatively few have been stud ied due to the difficulty of obtaining samples. Therefore, we investigated mitochondrial variation in pine martens, Martes martes, in order to underst and the extent to which they were affected by glacial cycles, and compared the results with an analysis of sequences from polecats, Mustela putorius. A general lack of ancient lineages, and a mismatch distribution that is con sistent with an expanding population, is evidence that the present-day M. m artes and Mu. putorius in central and northern Europe colonized from a sing le European refugium following a recent glaciation. There has also been int erspecific mitochondrial introgression between M. martes and the sable M. z ibellina in Fennoscandia.