Cladogenesis of the European brown hare (Lepus europaeus Pallas, 1778)

Abstract

A substantial portion of today's biodiversity is attributed to the climatic oscillations of the Pleistocene Ice Ages. Gradual but dramatic climate changes were accompanied by expansion, contraction, and isolation of populations, promoting the accumulation of genome differences and adaptations in refugial populations and resulting in allopatric differentiation in a variety of taxa. In the present study, partial mitochondrial DNA sequences of the widely distributed European brown hare (Lepus europaeus) were analyzed to test whether the species' present genetic structure is the result of postglacial re-colonization of Europe from Asia Minor (clade A) and the Balkans (clade B) only, as suggested previously, or if additional refugia are likely. Analyses indicated the presence of an additional refugium (Italy, clade I). The genealogic network of Italian hares displayed the tree-like structure expected from refugial populations, whereas central European brown hare haplotypes revealed a clear star-phylogeny indicative of past-bottleneck population growth. This population size expansion, which was confirmed by mismatch analysis, was estimated to have occurred ∼50-55 thousand years ago (kya). The divergence of clade A* from the remaining matrilines is estimated at 239 kya, whereas the divergence of the ancestors of clades B* and I from A*occurred about 128 kya. © 2008 Springer-Verlag.