Radtkey Ray R
Department of Zoology, University of Texas at Austin, Austin, Texas, 78712.
Evolution. 1996 Apr;50(2):604-623. doi: 10.1111/j.1558-5646.1996.tb03872.x.
A phylogenetic analysis using characters derived from mitochondrial DNA was used to show that the species of Phelsuma in the Seychelles Islands represent a single, monophyletic lineage that has diversified as a result of both historical and ecological factors. In the distant past, the Seychelles archipelago was physically invaded by a single species of Phesluma. Separate eustatic sea level changes likely led first to allopatric speciation and then to the secondary contact of these sister species. Differences in the relative timing of the secondary contact between island groups resulted in P. sundbergi evolving an intermediate body size in the group of islands associated with Mahé and a large body size, while sympatric with P. astriata, in the group of islands associated with Praslin. Ecological information was used to support the conclusion that the actual evolutionary mechanism for the body size shift was a response to frequency dependent natural selection of P. sundbergi in single-species and two-species competitive regimes.
利用线粒体DNA衍生特征进行的系统发育分析表明，塞舌尔群岛的日行守宫物种代表了一个单一的单系谱系，其多样化是历史和生态因素共同作用的结果。在遥远的过去，塞舌尔群岛曾被单一物种的日行守宫实际入侵。海平面的不同上升可能首先导致异域物种形成，然后导致这些姐妹物种的二次接触。岛屿群之间二次接触的相对时间差异导致桑德伯格日行守宫在与马埃岛相关的岛屿群中进化出中等体型，而在与普拉兰岛相关的岛屿群中与星点日行守宫同域分布时进化出大体型。生态信息被用来支持这样的结论，即体型转变的实际进化机制是桑德伯格日行守宫在单物种和双物种竞争机制中对频率依赖自然选择的一种反应。
