Islands are thought to facilitate adaptive radiation by providing release from competition and predation. Anole lizards are considered a classic example of this phenomenon: different ecological specialists (“ecomorphs”) evolved in the Caribbean Greater Antilles (Cuba, Hispaniola, Jamaica, and Puerto Rico), resulting in convergent assemblages that are not observed in mainland Latin America. Yet, the role of islands in facilitating adaptive radiation is more often implied than directly tested, leaving uncertain the role of biogeography in stimulating diversification. Here, we assess the proposed “island effect” on anole diversification using Bayesian phylogenetic comparative methods that explicitly incorporate rate heterogeneity across the tree and demonstrate two cases of would be false positives. We discovered that rates of speciation and morphological evolution of island and mainland anoles are equivalent, implying that islands provide no special context for exceptionally rapid diversification. Likewise, rates of evolution were equivalent between island anoles that arose via in situ versus dispersal-based mechanisms, and we found no evidence for island-specific rates of speciation or morphological evolution. Nonetheless, the origin of Anolis is characterized by a speciation pulse that slowed over time—a classic signature of waning ecological opportunity. Our findings cast doubt on the notion that islands catalyzed the anole adaptive radiation and instead point to a key innovation, adhesive toe pads, which facilitated the exploitation of many arboreal niches sparsely utilized by other iguanian lizards. The selective pressures responsible for arboreal niche diversification differ between islands and the mainland, but the tempo of diversification driven by these discordant processes is indistinguishable. [Anolis; Caribbean; key innovation; morphological evolution; RevBayes; speciation.]

中文翻译：

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来自创新而非岛屿的生态机会推动了 Anole Lizard 自适应辐射

岛屿被认为通过释放竞争和捕食来促进适应性辐射。Anole 蜥蜴被认为是这种现象的一个典型例子：在加勒比海大安的列斯群岛（古巴、伊斯帕尼奥拉、牙买加和波多黎各）进化出不同的生态专家（“ecomorphs”），导致在拉丁美洲大陆没有观察到的趋同组合。然而，岛屿在促进适应性辐射方面的作用往往是隐含的，而不是直接测试的，这使得生物地理学在刺激多样化方面的作用不确定。在这里，我们使用贝叶斯系统发育比较方法评估提出的“岛效应”对 anole 多样化的影响，该方法明确结合了整个树的速率异质性，并证明了两个可能是假阳性的情况。我们发现岛屿和大陆 anoles 的物种形成和形态进化率是相当的，这意味着岛屿没有为异常快速的多样化提供特殊的环境。同样，通过原位产生的岛屿 anoles 与基于分散的机制之间的进化率是相等的，我们没有发现岛屿特定的物种形成或形态进化率的证据。尽管如此，Anolis 起源的特点是物种形成脉冲随着时间的推移而减慢——这是生态机会减弱的经典特征。我们的研究结果对岛屿催化 anole 适应性辐射的概念提出了质疑，而是指出了一项关键创新，即粘性脚趾垫，它促进了对其他鬣蜥蜥蜴很少使用的许多树栖生态位的利用。负责树栖生态位多样化的选择压力在岛屿和大陆之间有所不同，但由这些不和谐过程驱动的多样化节奏是无法区分的。[阿诺利斯；加勒比；关键创新；形态进化；转贝叶斯；物种形成。]