Migration route estimation of the Jeju striped field mouse Apodemus agrarius chejuensis (Rodentia, Muridae).

The taxonomic relationship between two Korean field mice species, Apodemus agrarius coreae and A. a. chejuensis, as well as their possible historic migration routes, was examined by molecular genetic analysis of the complete mitochondrial cytochrome b gene of 73 mice collected from the Korean Peninsula and Jeju Island. Our findings suggest that A. a. coreae and A. a. chejuensis populations expanded and dispersed rapidly. Bayesian and network analysis showed that A. a. chejuensis is a clearly distinct population, and that A. a. chejuensis originated from the ancestral lineage of A. a. coreae. Based on our data, we hypothesize that the A. a. coreae population originated from eastern China or elsewhere. After the last glacial epoch, the lineage isolated from A. a. coreae had adapted to the new environment of Jeju Island, and with the reproductive isolation caused by the geographic barrier, this lineage eventually became a distinct population.