大陆及岛屿分布的安乐蜥属蜥蜴的环境适应性形态的趋同进化模式

熊荣川 译

分别分布在岛屿和大陆上的近缘支系，由于（差异的环境提供的）选择压不同，导致了它们获得不同的进化结果。相反，不同的岛屿和大陆环境中的支系可能获得相似的进化结果，或者岛屿和大陆的环境可能没有明显的差异。岛屿辐射研究最为透彻的动物类群是安乐蜥属物种。差异明显的形态特征或者环境适应性形态特征得到了描述，相同的形态特征在不同的安替列斯岛屿上独立进化出来。大陆安乐蜥蜴的适应辐射则较少得到关注。我们使用了大量的形态数据和新的系统发育假说证明大陆安乐蜥蜴并没有进化出和岛屿安乐蜥蜴相同的形态特征；即使一些岛屿物种和其它的岛屿物种形态相似，它们却和大陆物种有更近的亲缘关系。最多有六分之四的加勒比群岛形态特征被发现存在于大陆物种身上，而123个大陆物种中仅仅有15个可归类为加勒比式形态特征。不同的物种取样及系统发育假说得到的结果基本一致。趋同进化有加勒比形态特征的大陆物种主要是那些“草地-灌丛”类群。因此，在加勒比群岛上多次趋同进化的形态特征类型并没有在大陆种群中得到平行进化。这些结果和认为大陆和岛屿环境提供不同的选择压的假设一致。

关键词：适应辐射 趋同进化 环境适应性形态 种间互作 形态特征 形态空间

原文：

Patterns of ecomorphological convergence among mainland and island Anolis lizards

Differing selective pressures on islands versus the mainland may produce alternative evolutionary outcomes among closely related lineages. Conversely, lineages may be constrained to produce similar outcomes in different mainland and island environments, or mainland and island environments may not differ significantly. Among the best-studied island radiations are Caribbean Anolis lizards. Distinct morphotypes, or ‘ecomorphs’, have been described, and the same ecomorphs have evolved independently on each Greater Antillean island. The mainland Anolis radiation has received much less attention. We use a large morphological data set and a novel phylogenetic hypothesis to show that mainland Anolis did not evolve the same morphotypes as island Anolis, despite some island species being more closely related to mainland species than to island species that share their morphotype. A maximum of four of the six Caribbean ecomorphs were found to exist on the mainland, and just 15 of 123 mainland species are assignable to a Caribbean ecomorph. This result was insensitive to differing taxon samples and alternative phylogenetic hypotheses. Mainland convergence to a Caribbean ecomorph occurs only among species assigned to the grass-bush ecomorph. Thus, the ecomorphs that have evolved convergently multiple times in the Caribbean have not evolved in parallel on the mainland. These results are consistent with the hypothesis that mainland and island environments offer different selective pressures.

ADDITIONAL KEYWORDS: adaptive radiation – convergent evolution – ecomorph – interspecific interactions – morphology – morphospace.

参考文献：

 Patterns of ecomorphological convergence among mainland and island Anolis lizards.pdf