Adaptive radiation involves diversification along multiple trait axes, producing phenotypically diverse, species-rich lineages. Theory generally predicts that multi-trait evolution occurs via a "stages" model, with some traits saturating early in a lineage's history, and others diversifying later. Despite its multidimensional nature, however, we know surprisingly little about how different suites of traits evolve during adaptive radiation. Here, we investigated the rate, pattern, and timing of morphological and physiological evolution in the anole lizard adaptive radiation from the Caribbean island of Hispaniola. Rates and patterns of morphological and physiological diversity are largely unaligned, corresponding to independent selective pressures associated with structural and thermal niches. Cold tolerance evolution reflects parapatric divergence across elevation, rather than niche partitioning within communities. Heat tolerance evolution and the preferred temperature evolve more slowly than cold tolerance, reflecting behavioral buffering, particularly in edge-habitat species (a pattern associated with the Bogert effect). In contrast to the nearby island of Puerto Rico, closely related anoles on Hispaniola do not sympatrically partition thermal niche space. Instead, allopatric and parapatric separation across biogeographic and environmental boundaries serves to keep morphologically similar close relatives apart. The phenotypic diversity of this island's adaptive radiation accumulated largely as a by-product of time, with surprisingly few exceptional pulses of trait evolution. A better understanding of the processes that guide multidimensional trait evolution (and nuance therein) will prove key in determining whether the stages model should be considered a common theme of adaptive radiation.

中文翻译：

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一组加勒比海 anoles 中没有独立性状进化阶段的适应性辐射。


适应性辐射涉及沿多个性状轴的多样化，产生表型多样、物种丰富的谱系。理论通常预测多性状进化是通过 “阶段 ”模型发生的，一些性状在谱系历史的早期就饱和了，而另一些性状则在以后多样化。然而，尽管它具有多维性质，但我们对适应性辐射期间不同特征套件如何演变知之甚少。在这里，我们研究了来自加勒比海伊斯帕尼奥拉岛的 anole 蜥蜴适应性辐射的形态和生理进化的速率、模式和时间。形态学和生理多样性的速率和模式在很大程度上是不一致的，对应于与结构和热生态位相关的独立选择压力。耐寒进化反映了跨海拔的旁系分化，而不是群落内的生态位划分。耐热性演变和首选温度的演变比耐寒性更慢，这反映了行为缓冲，特别是在边缘栖息地物种中（与 Bogert 效应相关的模式）。与附近的波多黎各岛相比，伊斯帕尼奥拉岛上密切相关的 anoles 并没有同位划分热生态位空间。相反，跨越生物地理和环境边界的异体和旁系分离有助于将形态相似的近亲分开。这个岛屿适应性辐射的表型多样性在很大程度上是作为时间的副产品积累的，令人惊讶的是，很少有特殊的性状进化脉冲。 更好地了解指导多维性状进化的过程（以及其中的细微差别）将是确定阶段模型是否应被视为适应性辐射的常见主题的关键。