Lee Michael S Y, Sanders Kate L, King Benedict, Palci Alessandro
Earth Sciences Section, South Australian Museum, North Terrace, Adelaide, SA 5000, Australia; School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; School of Biological Sciences, Flinders University, PO Box 2100, Adelaide, SA 5001, Australia.
School of Biological Sciences , University of Adelaide , Adelaide, SA 5005, Australia.
R Soc Open Sci. 2016 Jan 20;3(1):150277. doi: 10.1098/rsos.150277. eCollection 2016 Jan.
The relationship between rates of diversification and of body size change (a common proxy for phenotypic evolution) was investigated across Elapidae, the largest radiation of highly venomous snakes. Time-calibrated phylogenetic trees for 175 species of elapids (more than 50% of known taxa) were constructed using seven mitochondrial and nuclear genes. Analyses using these trees revealed no evidence for a link between speciation rates and changes in body size. Two clades (Hydrophis, Micrurus) show anomalously high rates of diversification within Elapidae, yet exhibit rates of body size evolution almost identical to the general elapid 'background' rate. Although correlations between speciation rates and rates of body size change exist in certain groups (e.g. ray-finned fishes, passerine birds), the two processes appear to be uncoupled in elapid snakes. There is also no detectable shift in diversification dynamics associated with the colonization of Australasia, which is surprising given that elapids appear to be the first clade of venomous snakes to reach the continent.
在眼镜蛇科（剧毒蛇类中最大的辐射类群）中，研究了物种多样化速率与体型变化速率（表型进化的常见替代指标）之间的关系。利用7个线粒体基因和核基因构建了175种眼镜蛇（超过已知分类单元的50%）的时间校准系统发育树。使用这些树进行的分析没有发现物种形成速率与体型变化之间存在联系的证据。两个分支（海蛇属、珊瑚蛇属）在眼镜蛇科中显示出异常高的多样化速率，但体型进化速率几乎与一般眼镜蛇的“背景”速率相同。尽管在某些类群（如辐鳍鱼类、雀形目鸟类）中物种形成速率与体型变化速率之间存在相关性，但这两个过程在眼镜蛇科蛇类中似乎是解耦的。与澳大拉西亚的殖民化相关的多样化动态也没有可检测到的转变，鉴于眼镜蛇似乎是第一批到达该大陆的毒蛇类群，这一点令人惊讶。
