Vieites David R, Min Mi-Sook, Wake David B
Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA 94720-3160, USA.
Proc Natl Acad Sci U S A. 2007 Dec 11;104(50):19903-7. doi: 10.1073/pnas.0705056104. Epub 2007 Dec 5.
A phylogeny and timescale derived from analyses of multilocus nuclear DNA sequences for Holarctic genera of plethodontid salamanders reveal them to be an old radiation whose common ancestor diverged from sister taxa in the late Jurassic and underwent rapid diversification during the late Cretaceous. A North American origin of plethodontids was followed by a continental-wide diversification, not necessarily centered only in the Appalachian region. The colonization of Eurasia by plethodontids most likely occurred once, by dispersal during the late Cretaceous. Subsequent diversification in Asia led to the origin of Hydromantes and Karsenia, with the former then dispersing both to Europe and back to North America. Salamanders underwent rapid episodes of diversification and dispersal that coincided with major global warming events during the late Cretaceous and again during the Paleocene-Eocene thermal optimum. The major clades of plethodontids were established during these episodes, contemporaneously with similar phenomena in angiosperms, arthropods, birds, and mammals. Periods of global warming may have promoted diversification and both inter- and transcontinental dispersal in northern hemisphere salamanders by making available terrain that shortened dispersal routes and offered new opportunities for adaptive and vicariant evolution.
通过对全北区无肺螈科蝾螈属的多位点核DNA序列分析得出的系统发育和时间尺度显示，它们是一个古老的辐射类群，其共同祖先在侏罗纪晚期与姐妹类群分化，并在白垩纪晚期经历了快速多样化。无肺螈科起源于北美，随后在整个大陆范围内多样化，不一定仅集中在阿巴拉契亚地区。无肺螈科对欧亚大陆的殖民很可能只发生过一次，是在白垩纪晚期通过扩散实现的。随后在亚洲的多样化导致了水螈属和山溪螈属的起源，前者随后扩散到欧洲并回到北美。蝾螈经历了快速的多样化和扩散事件，这些事件与白垩纪晚期以及古新世-始新世极热事件期间的主要全球变暖事件同时发生。无肺螈科的主要分支在这些事件中形成，与被子植物、节肢动物、鸟类和哺乳动物中的类似现象同时出现。全球变暖时期可能通过提供缩短扩散路线并为适应性和替代进化提供新机会的地形，促进了北半球蝾螈的多样化以及洲际和跨大陆扩散。
