Population structure and landscape genetics of two endangered frog species of Genus Odorrana: different scenarios on two islands

Isolation by distance and landscape connectivity are fundamental factors underlying speciation and evolution. To understand how landscapes affect gene flow and shape population structures, island species provide intrinsic study objects. We investigated the effects of landscapes on the population structure of the endangered frog species, Odorrana ishikawae and O. splendida, which each inhabit an island in southwest Japan. This was done by examining population structure, gene flow, and demographic history of each species by analyzing 12 microsatellite loci and exploring causal environmental factors through ecological niche modeling (ENM) and the cost-distance approach. Our results revealed that the limited gene flow and multiple population structure in O. splendida and the single population structure in O. ishikawae were maintained after divergence of the species through ancient vicariance between islands. We found that genetic distance correlated with geographic dist ance between populat...