Department of Organismic and Evolutionary Biology & Museum of Comparative Zoology, Harvard University, 26 Oxford St., Cambridge, Massachusetts, 02134; Current address: School of Science, Engineering and Mathematics, Bethune-Cookman University, 640 Dr Mary McLeod Bethune Blvd, Daytona Beach, Florida, 32114.
Evolution. 2013 Nov;67(11):3175-90. doi: 10.1111/evo.12184. Epub 2013 Jul 3.
The evolutionary processes that produce adaptive radiations are enigmatic. They can only be studied after the fact, once a radiation has occurred and been recognized, rather than while the processes are ongoing. One way to connect pattern to process is to study the processes driving divergence today among populations of species that belong to an adaptive radiation, and compare the results to patterns observed at a deeper, macroevolutionary level. We tested whether evolution is a deterministic process with similar outcomes during different stages of the adaptive radiation of Anolis lizards. Using a clade of terrestrial-scansorial lizards in the genus Anolis, we inferred the adaptive basis of spatial variation among contemporary populations and tested whether axes of phenotypic differentiation among them mirror known axes of diversification at deeper levels of the anole radiation. Nonparallel change associated with genetic divergence explains the vast majority of geographic variation. However, we found phenotypic variation to be adaptive as confirmed by convergence in populations occurring in similar habitats in different mountain ranges. Morphological diversification among populations recurs deterministically along two axes of diversification previously identified in the anole radiation, but the characters involved differ from those involved in adaptation at higher levels of anole phylogeny.
产生适应性辐射的进化过程是神秘的。只有在辐射发生并被识别之后，才能对其进行研究，而不能在过程进行时进行研究。将模式与过程联系起来的一种方法是研究属于适应性辐射的物种群体中导致分歧的过程，并将结果与在更深层次的宏观进化水平上观察到的模式进行比较。我们检验了进化是否是一个具有相似结果的确定性过程，在不同阶段的变色龙蜥蜴的适应性辐射。利用变色龙属的一个陆生蜥蜴类群，我们推断了当代种群之间空间变异的适应性基础，并检验了它们之间的表型分化轴是否反映了在变色龙辐射更深层次的已知多样化轴。与遗传分歧相关的非平行变化解释了绝大多数地理变异。然而，我们发现表型变异是适应性的，这一点得到了在不同山脉中发生在相似生境中的种群中的趋同进化的证实。在以前在变色龙辐射中确定的两个多样化轴上，种群之间的形态多样化是确定性的，但所涉及的特征与在变色龙系统发育较高层次的适应所涉及的特征不同。
