Jowers Michael J, Lehtinen Richard M, Downie Roger J, Georgiadis Andrew P, Murphy John C
Departamento de Etologia y Conservacion de la Biodiversidad, Estacion Biologica de Doñana C/Americo Vespucio, CSIC (Consejo Superior de Investigaciones Cientificas) , Sevilla, España , Spain .
Mitochondrial DNA. 2015 Aug;26(4):613-8. doi: 10.3109/19401736.2014.880888. Epub 2014 Feb 3.
The presence of Hyalinobatrachium orientale in Tobago and in northeastern Venezuela is puzzling as this species is unknown from the island of Trinidad, an island often hypothesized to be a stepping-stone for the mainland fauna to colonize Tobago. A period of extended isolation on Tobago could result in the Hyalinobatrachium population becoming distinct from the mainland H. orientale. Here, we use 12S and 16S rDNA gene fragments from nine H. orientale specimens from Tobago and the mainland to assess their relationship and taxonomy, as well as the tempo and mode of speciation. The results suggest H. orientale from Venezuela and Tobago are monophyletic and the two populations diverged about 3 million years ago. This estimate corresponds with the drier climate and lower sea levels of the Pliocene glaciation periods. We hypothesize that lower sea levels resulted in land-bridge formations connecting the mainland and Tobago, with a corridor of habitat allowing H. orientale to colonize Tobago to the west of Trinidad.
在多巴哥岛和委内瑞拉东北部发现东方玻璃蛙令人感到困惑，因为在特立尼达岛上并未发现该物种，而特立尼达岛常被认为是大陆动物群殖民多巴哥岛的跳板。多巴哥岛长期的隔离可能导致东方玻璃蛙种群与大陆的东方玻璃蛙产生差异。在此，我们使用来自多巴哥岛和大陆的9个东方玻璃蛙样本的12S和16S rDNA基因片段，来评估它们之间的关系和分类，以及物种形成的速度和模式。结果表明，来自委内瑞拉和多巴哥岛的东方玻璃蛙是单系的，两个种群大约在300万年前分化。这一估计与上新世冰期较为干燥的气候和较低的海平面相符。我们推测，较低的海平面导致连接大陆和多巴哥岛的陆桥形成，有一条栖息地走廊使东方玻璃蛙能够从特立尼达岛以西殖民多巴哥岛。
