Evolution and biogeography of talpid moles from continental East Asia and the Japanese islands inferred from mitochondrial and nuclear gene sequences.

We sequenced the cytochrome b gene from two little-studied mammal species from the highlands of Southwest China, the long-tailed mole Scaptonyx fusicaudus and the gracile shrew-like mole Uropsilus gracilis. This data was used to examine the phylogenetic relationships among 19 talpid species within the family Talpidae (Mammalia: Eulipotyphla). Cytochrome b gene trees supported a basal placement of shrew-like moles (Uropsilus) within the Talpidae, and suggested that fossorial specializations arose twice during talpid evolution. To assess the evolutionary relationships of moles endemic to this region, we additionally sequenced the 12S rRNA gene and the nuclear recombination-activating gene-1 from eight and ten East Asian taxa, respectively. Analyses of these single and concatenated data sets suggested that East Asian shrew moles diverged prior to the evolution of fossorial Eurasian moles. However, we were unable to determine whether semi-fossorial shrew moles are monophyletic. In contrast, fossorial Eurasian genera (Talpa, Mogera and Euroscaptor) were consistently found to form a monophyletic clade, with Mogera and Euroscaptor representing sister taxa. Furthermore, this fossorial clade grouped with the semi-aquatic Desmana, although with fairly low (35-62%) bootstrap support. Mogera imaizumii was found to be more closely related to M. wogura than to M. tokudae. This implies that the ancestors of these three species entered Japan from the Asian continent in this order via a series of migration events, suggesting that the Japanese Islands have played an important role in preserving mole lineages from ancient to recent times.