Refugia in Glacial Ages Led to the Current Discontinuous Distribution Patterns of the Dark Red-backed VoleMyodes rexon Hokkaido, Japan

Abstract

The terrestrial mammalian fauna of the North Japanese island, Hokkaido, is more similar to that of Southern Siberia than to the main island of Japan, Honshu. Three species of the genus Myodes (Muridae, Rodentia) are found on Hokkaido, but not on Honshu. While Myodes rufocanus and M. rutilus are widely distributed across Hokkaido as well as the Eurasian continent, M. rex, which is endemic to Hokkaido and its adjacent islands, shows a discontinuous distribution pattern. We analyzed the phylogeographic history of M. rex using the mitochondrial DNA control region in order to interpret their discontinuous distribution pattern. Phylogenetic relationships among 54 distinct haplotypes showed that M. rex can be divided into four clades that occur on the northern, central, and southern regions of the Hokkaido mainland and on Rishiri Island, respectively. The phylogroups in the northern and central regions were largely separated in space, although several areas of sympatry were found. The phylogroup in the southern region, which was clearly separated from other phylogroups, showed markedly low genetic variability. All analyzed individuals from the population on Rishiri belonged to a separate lineage. Across a range of divergence rate estimates, we dated the basal divergence of all phylogroups to the mid to late Pleistocene, with subsequent signals of population expansion within lineages. We conclude that current phylogeographic structure in M. rex likely reflects Pleistocene survival in several separate refugia in situ. Past glacial ages have thus played an important role in shaping the current distribution patterns of mammalian species on Hokkaido.

Species trees, temporal divergence and historical biogeography of coastal rove beetles (Coleoptera: Staphylinidae) reveal their early Miocene origin and show that most divergence events occurred in the early Pliocene along the Pacific coasts

“…zerchei and A . nubis , with a boundary between southern Hokkaido and northern Honshu; a similar separation of lineages can be found in other animal groups (Kawai et al., ). The divergence between A .…”

Late Pleistocene climate change and population dynamics of Japanese Myodes voles inferred from mitochondrial cytochrome b sequences

“…In addition, the mtDNA composition of the Kii population of M. andersoni represents two distinct lineages (Iwasa and Suzuki 2002), perhaps reflecting past migration from central Honshu to the Kii Peninsula at different evolutionary times. Lastly, population expansion events have been noted in M. rex from previous mtDNA analysis (Kawai et al 2013). Despite these previous studies, a comprehensive evolutionary history of Myodes in Japan has not yet been achieved, partly due to a lack of information about population dynamics and partly due to the lack of consensus from mtDNA data (e.g., Herman et al 2014; Suzuki et al 2015).…”

Species delimitation in the Aleochara fucicola species complex (Coleoptera: Staphylinidae: Aleocharinae) and its phylogenetic relationships

“…The boundary between southern Hokkaido and northern Honshu separates lineages in other animal groups (Kawai et al . ). This distributional information further supports the existence of two species, A .…”