Laboratorio de Ecología Evolutiva, Departamento de Biología, Universidad Nacional de Colombia, Sede Bogotá, Colombia.
Grupo de Morfología y Ecología Evolutiva, Universidad Nacional de Colombia, Sede Bogotá, Colombia.
J Anat. 2022 May;240(5):850-866. doi: 10.1111/joa.13608. Epub 2021 Dec 12.
Anolis lizards have evolved morphologies in response to different selective factors related to microhabitat use. Morphological diversity exhibits evolutionary patterns that reveal similarities and unique regional traits among the mainland and island environments and among Greater Antilles and Lesser Antilles islands. In the Greater Antilles and mainland environments anole species are classified into morphological/ecological groups, that are known as morphotypes (mainland) or ecomorphs (Greater Antilles). Morphotypes are defined only with morphological information; in contrast, for ecomorph assignment both morphology and ethology are required. For mainland species distributed in northwestern South America 10 morphotypes were proposed to include the morphological diversity of 59 species. We obtained data from body size, limbs length, tail length, and the number of lamellae for an additional ten species occurring in the same region and assigned them into morphotypes. We also collected data of the claw and toepad diversity of mainland and island Anolis from northwestern South America and compared it to the claw and toepads morphology recorded for the Greater Antilles and Lesser Antilles islands, under a phylogenetic framework. We found new island morphotypes (MT11-MT13) of Anolis from northwestern South America. When comparing claws and toepads morphology among the 13 morphotypes we found that morphological variation of these traits partially corresponds to morphotype groups. For instance, habitat specialist species like Anolis heterodermus, classified in morphotype 4 (MT4), have a characteristic design of broad toepad and reduced claws, and non-unique design of toepads and claws occurs in morphotypes MT1, MT2, MT5, MT10, and MT13. We also compared claws and toepads of fore and hindlimbs within the same individual, and found that even if limbs show differences in claws and toepads, suggesting that they perform differential biomechanical function, the degree of within individual variation is specific and not related to morphotype assignment. Our data supported the convergent and unique regional evolution among mainland and island anoles, and revealed aspects of correlative evolution of functional traits of claws and toepads that probably are related to minor differences in microhabitat use among mainland and island species, as suggested by previously published literature. Lastly, the evolutionary pattern of morphological diversity of claws and toepads of Anolis in the mainland and island environment supports both unique regional traits and common selective and historical factors that have molded Anolis morphological diversity.
鬣蜥已经进化出各种形态，以适应与微生境利用相关的不同选择因素。形态多样性表现出进化模式，揭示了大陆和岛屿环境以及大安的列斯群岛和小安的列斯群岛之间的相似之处和独特的区域特征。在大安的列斯群岛和大陆环境中，鬣蜥物种被分为形态/生态群，称为形态型（大陆）或生态型（大安的列斯群岛）。形态型仅根据形态信息来定义；相比之下，生态型的分配既需要形态学信息，也需要行为学信息。对于分布在南美洲西北部的大陆物种，提出了 10 种形态型，以包含 59 种物种的形态多样性。我们从身体大小、四肢长度、尾巴长度和鳞片数量等方面获得了另外 10 种在同一地区出现的物种的数据，并将它们分配到形态型中。我们还收集了来自南美洲西北部大陆和岛屿的鬣蜥的爪和跖垫多样性的数据，并在系统发育框架下将其与大安的列斯群岛和小安的列斯群岛记录的爪和跖垫形态进行了比较。我们发现了来自南美洲西北部的新的岛屿形态型（MT11-MT13）的鬣蜥。在比较 13 种形态型的爪和跖垫形态时，我们发现这些特征的形态变异部分对应于形态型组。例如，像 Anolis heterodermus 这样的栖息地特化物种，被归类为形态型 4（MT4），具有宽大的跖垫和减少的爪子的特征设计，而在形态型 MT1、MT2、MT5、MT10 和 MT13 中出现了非独特的跖垫和爪子设计。我们还比较了同一个体前后肢的爪和跖垫，发现即使四肢在爪和跖垫上存在差异，表明它们执行不同的生物力学功能，但个体内部的变异程度是特定的，与形态型分配无关。我们的数据支持了大陆和岛屿鬣蜥之间的趋同和独特的区域进化，并揭示了爪子和跖垫功能特征的相关进化方面，这可能与大陆和岛屿物种之间微生境利用的微小差异有关，正如之前发表的文献所表明的那样。最后，大陆和岛屿环境中鬣蜥的爪子和跖垫形态多样性的进化模式支持了独特的区域特征和共同的选择和历史因素，这些因素塑造了鬣蜥的形态多样性。
