From Mainland to Islands: Colonization History in the Tree Frog (Anura: Rhacophoridae)

The origin and colonization history of , a genus of small arboreal tree frogs breeding exclusively in shallow swamps, is under disputed. On the basis of comprehensive sampling program, the evolutionary history of is investigated based on 3 mitochondrial genes. Our results indicate that the genus originated in the Asian mainland and subsequently arrived at its current distribution in Borneo, Taiwan, Ryukyu, and Hainan islands by a series of dispersal events. Moreover, the colonization of Taiwan from mainland Asia has occurred 2 times. The initial colonization of Taiwan occurred at 3.46-8.68 Mya (95% highest posterior density), which rejects the hypothesis that probably originated from Taiwan during the early Oligocene and favors the model of Neogene-origin rather than the model of Quaternary-origin for Taiwanese . has dispersed from Taiwan to the Ryukyus once or 2 times pending more data. Both transoceanic dispersal and landbridge dispersal have played a role in the colonization process; the former resulted in the colonization of Taiwan and the Ryukyus and the latter led to the colonization of Borneo and Hainan.