Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, 20560.
Department of Ecology and Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, Michigan, 48109.
Evolution. 2021 Jun;75(6):1361-1376. doi: 10.1111/evo.14230. Epub 2021 May 5.
Phenotypic variation among populations, as seen in the signaling traits of many species, provides an opportunity to test whether similar factors generate repeated phenotypic patterns in different parts of a species' range. We investigated whether genetic divergence, abiotic gradients, and sympatry with closely related species explain variation in the dewlap colors of Amazon Slender Anoles, Anolis fuscoauratus. To this aim, we characterized dewlap diversity in the field with respect to population genetic structure and evolutionary relationships, assessed whether dewlap phenotypes are associated with climate or landscape variables, and tested for nonrandom associations in the distributions of A. fuscoauratus phenotypes and sympatric Anolis species. We found that dewlap colors vary among but not within sites in A. fuscoauratus. Regional genetic clusters included multiple phenotypes, while populations with similar dewlaps were often distantly related. Phenotypes did not segregate in environmental space, providing no support for optimized signal transmission at a local scale. Instead, we found a negative association between certain phenotypes and sympatric Anolis species with similar dewlap color attributes, suggesting that interactions with closely related species promoted dewlap divergence among A. fuscoauratus populations. Amazon Slender Anoles emerge as a promising system to address questions about parallel trait evolution and the contribution of signaling traits to speciation.
种群间的表型变异，如许多物种的信号特征所示，为测试相似因素是否在物种分布的不同区域产生重复的表型模式提供了机会。我们调查了遗传分化、非生物梯度和与近缘物种的同域分布是否解释了亚马逊瘦蜥（Anolis fuscoauratus）的垂肉颜色变异。为此，我们从种群遗传结构和进化关系的角度在野外对垂肉多样性进行了描述，评估了垂肉表型是否与气候或景观变量有关，并测试了 A. fuscoauratus 表型和同域分布的 Anolis 物种的分布是否存在非随机关联。我们发现，在 A. fuscoauratus 中，垂肉颜色在不同地点之间存在差异，但在同一地点内不存在差异。区域遗传聚类包括多种表型，而具有相似垂肉的种群通常亲缘关系较远。表型没有在环境空间中分离，这不能支持在局部尺度上进行优化信号传递。相反，我们发现某些表型与具有相似垂肉颜色属性的同域 Anolis 物种之间存在负相关关系，这表明与近缘物种的相互作用促进了 A. fuscoauratus 种群之间的垂肉分化。亚马逊瘦蜥成为一个很有前途的系统，可以用来解决关于平行特征进化和信号特征对物种形成贡献的问题。
