Poe Steven, Anderson Christopher G
Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM, USA.
PeerJ. 2019 Jan 3;6:e6040. doi: 10.7717/peerj.6040. eCollection 2019.
The evolution of distinct ecologies and correlated morphologies ("ecomorphs," in combination) among similar species allows sympatric occupation of diverse microhabitats. Particular ecomorphs may evolve repeatedly, that is, convergently, as separate lineages arrive at similar solutions. Caribbean lizards (anoles) are a classic ecomorph system, particularly well-studied for the diverse morphotypes resulting from adaptive radiations. But few studies have analyzed the equally species-diverse mainland . Here, we use clustering analyses of nine traits for 336 species of to objectively identify morphological groups (morphotypes). We analyze the presence of recovered morphotypes on mainland and islands in general and relative to the composition of 76 mainland and 91 island anole assemblages. We test for evolutionary convergence of morphotypes within and between mainland and island environments by mapping our recovered morphotypes onto recent phylogenetic estimates and by analyzing four of our measured traits using program SURFACE. We find that particular morphotypes tend to be restricted to either mainland or island environments. Morphotype diversity and convergence are not concentrated within either island or mainland environments. Morphotype content of assemblages differs between mainland and island areas, with island assemblages displaying greater numbers of morphotypes than mainland assemblages. Taken with recent research, these results suggest a restructuring of one of the classic adaptive radiation stories and a reconsideration of research concerning island-mainland faunal differences. Island radiations of anoles are unexceptional relative to mainland radiations with regard to species count, rates of speciation and phenotypic evolution, morphotype diversity, and rates of convergence. But local island assemblage appear to be more diverse than mainland assemblages. The explanation for this assemblage disparity may reside in one of the classic hypothesized island-mainland environmental differences (i.e., greater numbers of predators/competitors/environmental complexity on the mainland). Similarity between mainland and island anole radiations may indicate exceptional evolution in the anole clade overall or ordinary evolution in an extraordinarily studied clade.
相似物种之间独特生态和相关形态（合称“生态形态”）的演化，使得同域物种能够占据多样的微生境。特定的生态形态可能会反复演化，即趋同演化，因为不同的谱系会得出相似的解决方案。加勒比蜥蜴（安乐蜥）是一个经典的生态形态系统，因其适应性辐射产生的多样形态类型而得到了充分研究。但很少有研究分析同样物种丰富的大陆地区。在这里，我们对336种安乐蜥的九个特征进行聚类分析，以客观地识别形态类群（形态类型）。我们分析了在大陆和岛屿上总体以及相对于76个大陆和91个岛屿安乐蜥群落组成而言所恢复的形态类型的存在情况。我们通过将恢复的形态类型映射到最新的系统发育估计上，并使用SURFACE程序分析我们测量的四个特征，来检验大陆和岛屿环境内部以及之间形态类型的进化趋同情况。我们发现特定的形态类型往往局限于大陆或岛屿环境。形态类型的多样性和趋同并非集中在岛屿或大陆环境中。大陆和岛屿地区群落的形态类型组成不同，岛屿群落显示出比大陆群落更多的形态类型。结合最近的研究，这些结果表明对经典适应性辐射故事之一进行了重构，并重新考虑了有关岛屿 - 大陆动物区系差异的研究。就物种数量、物种形成和表型进化速率、形态类型多样性以及趋同速率而言，安乐蜥在岛屿上的辐射相对于在大陆上的辐射并无异常。但当地岛屿群落似乎比大陆群落更加多样。这种群落差异的解释可能在于经典假设的岛屿 - 大陆环境差异之一（即大陆上有更多的捕食者/竞争者/环境复杂性）。大陆和岛屿安乐蜥辐射之间的相似性可能表明安乐蜥类群整体存在异常进化，或者是在一个被过度研究的类群中存在普通进化。
