趋同进化定义为不同谱系中相似表型的独立进化。它的存在强调了外部选择压力在进化史上的重要性,揭示了功能相似的适应如何通过多种进化途径来应对持续的生态挑战。然而,许多收敛的例子,特别是在密切相关的物种中,涉及相同基因或发育途径的平行变化,提高了在更深层次机制水平上的同源性是表型趋同的重要促进因素的可能性。使用Ranitomeya属,一个年轻人,新热带毒蛙的颜色多样的辐射,我们着手(1)为这个群体提供一个系统发育框架,(2)利用这个框架来确定颜色表型是否收敛,和(3)表征潜在的着色机制,以测试颜色会聚是否通过相同或不同的物理机制发生。我们使用超保守元素生成了Ranitomeya的系统发育,并研究了明亮着色的物理机制,专注于皮肤色素。使用系统发育比较方法,我们发现了几个颜色收敛的例子,涉及类胡萝卜素和蝶呤色素的几种得失。我们还发现了一个令人信服的非平行收敛的例子,where,在一个血统中,红色着色是通过红色蝶呤色素drosopterin进化而来的,在另一个谱系中通过红色酮类胡萝卜素。此外,在另一个谱系中,“微红色”着色主要通过结构颜色机制演变。我们的研究表明,即使在密切相关物种的辐射中,收敛演化可以通过并行和非并行机制发生,挑战近亲之间相似表型通过相同机制进化的假设。
Convergent evolution is defined as the independent evolution of similar phenotypes in different lineages. Its existence underscores the importance of external selection pressures in evolutionary history, revealing how functionally similar adaptations can evolve in response to persistent ecological challenges through a diversity of evolutionary routes. However, many examples of convergence, particularly among closely related species, involve parallel changes in the same genes or developmental pathways, raising the possibility that homology at deeper mechanistic levels is an important facilitator of phenotypic convergence. Using the genus Ranitomeya, a young, color-diverse radiation of Neotropical poison frogs, we set out to 1) provide a phylogenetic framework for this group, 2) leverage this framework to determine if color phenotypes are convergent, and 3) to characterize the underlying coloration mechanisms to test whether color convergence occurred through the same or different physical mechanisms. We generated a phylogeny for Ranitomeya using ultraconserved elements and investigated the physical mechanisms underlying bright coloration, focusing on skin pigments. Using phylogenetic comparative methods, we identified several instances of color convergence, involving several gains and losses of carotenoid and pterin pigments. We also found a compelling example of nonparallel convergence, where, in one lineage, red coloration evolved through the red pterin pigment drosopterin, and in another lineage through red ketocarotenoids. Additionally, in another lineage, \"reddish\" coloration evolved predominantly through structural color mechanisms. Our study demonstrates that, even within a radiation of closely related species, convergent evolution can occur through both parallel and nonparallel mechanisms, challenging the assumption that similar phenotypes among close relatives evolve through the same mechanisms.