Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
Mol Phylogenet Evol. 2012 Nov;65(2):642-53. doi: 10.1016/j.ympev.2012.07.019. Epub 2012 Jul 27.
The Anderson's crocodile newt, Echinotriton andersoni, is considered a relic and endangered species distributed in the Central Ryukyus. To elucidate phylogenetic relationships and detailed genetic structures among populations, we analyzed variation in the mitochondrial cytochrome b gene. Results strongly support a primary dichotomy between populations from the Amami and Okinawa Island Groups with substantial genetic divergence, favoring a primary divergence between the two island groups. Within the latter, populations from the southern part of Okinawajima Island are shown to be more closely related to those from Tokashikijima Island than to those from the northern and central parts of Okinawajima. The prominent genetic divergence between the two island groups of the Central Ryukyus seems to have initiated in the Miocene, i.e., prior to formation of the strait that has consistently separated these island groups since the Pleistocene. The ancestor of the southern Okinawajima-Tokashikijima is estimated to have migrated from the northern and central parts of Okinawajima into southern Okinawajima at the Pleistocene, and dispersed into Tokashikijima subsequently.
安德森氏小鲵，Echinotriton andersoni，被认为是分布在琉球中部的一种遗迹和濒危物种。为了阐明种群间的系统发育关系和详细的遗传结构，我们分析了线粒体细胞色素 b 基因的变异。结果强烈支持在奄美和冲绳岛群之间存在主要二分法，具有实质性的遗传分歧，有利于两个岛群之间的主要分歧。在后一个群体中，来自冲绳岛南部的种群与来自德之岛的种群比来自冲绳岛北部和中部的种群更为密切相关。琉球中部这两个岛群之间的显著遗传分歧似乎始于中新世，即自更新世以来一直分隔这些岛群的海峡形成之前。估计来自冲绳岛南部和德之岛的祖先在更新世时期从冲绳岛北部和中部迁移到冲绳岛南部，随后扩散到德之岛。
