Data from: Trophic divergence despite morphological convergence in a continental radiation of snakes

Ecological and phenotypic convergence is a potential outcome of adaptive radiation in response to ecological opportunity. However, a number of factors may limit convergence during evolutionary radiations, including interregional differences in biogeographic history and clade-specific constraints on form and function. Here, we demonstrate that a single clade of terrestrial snakes from Australia—the oxyuranine elapids—exhibits widespread morphological convergence with a phylogenetically diverse and distantly related assemblage of snakes from North America. Australian elapids have evolved nearly the full spectrum of phenotypic modalities that occurs among North American snakes. Much of the convergence appears to involve the recurrent evolution of stereotyped morphologies associated with foraging mode, locomotion and habitat use. By contrast, analysis of snake diets indicates striking divergence in feeding ecology between these faunas, partially reflecting regional differences in ecological allometry between Australia and North America. Widespread phenotypic convergence with the North American snake fauna coupled with divergence in feeding ecology are clear examples of how independent continental radiations may converge along some ecological axes yet differ profoundly along others.

生态与表型趋同是响应生态机遇的适应辐射所可能产生的结果。然而，诸多因素可能限制演化辐射过程中的趋同现象，包括不同区域间的生物地理历史差异，以及支系特有的形态与功能约束。本研究证实，澳大利亚陆生蛇类的单一支系——澳太攀蛇亚科（Oxyuraninae）眼镜蛇类群，与北美系统发育多样且亲缘关系疏远的蛇类集合存在广泛的形态趋同。澳大利亚眼镜蛇类已演化出几乎覆盖北美蛇类全部表型类型的谱系。此类趋同大多涉及与觅食模式、运动方式及栖息地利用相关的定型形态的反复演化。相较而言，对蛇类食性的分析显示，这两个动物区系在取食生态上存在显著分化，该差异部分反映了澳大利亚与北美之间的生态异速生长区域差异。与北美蛇类动物区系广泛的表型趋同，结合取食生态的显著分化，清晰展现了独立大陆辐射演化事件如何在部分生态轴向上发生趋同，却在其他轴向上产生根本性差异。