School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Department of Biology, Washington University, St. Louis, MO 63130, USA.
Biol Lett. 2023 Jul;19(7):20230160. doi: 10.1098/rsbl.2023.0160. Epub 2023 Jul 5.
Positive allometry of signalling traits has often been taken as evidence for sexual selection. However, few studies have explored interspecific differences in allometric scaling relationships among closely related species that vary in their degree of ecological similarity. lizards possess an elaborate retractable throat fan called a dewlap that is used for visual communication and differs greatly in size and colour among species. We observed that dewlaps demonstrate positive allometry: relative dewlap size increases with body size. We also observed that coexisting species are divergent in signal size allometries, while convergent species-similar in other aspects of ecology, morphology and behaviour-typically share similar dewlap allometric scaling relationships. These patterns suggest that dewlap scaling relationships may follow the same pattern as other traits in the anole radiation, where ecologically different sympatric species have evolved a suite of divergent traits.
信号特征的正异速生长通常被视为性选择的证据。然而，很少有研究探索过在生态相似性程度不同的密切相关物种之间，在异速生长比例关系上的种间差异。蜥蜴拥有一个精巧的可伸缩的喉咙扇，称为垂肉，用于视觉交流，并且在物种之间在大小和颜色上差异很大。我们观察到垂肉表现出正异速生长：相对垂肉大小随体型大小而增加。我们还观察到，共存的物种在信号大小的异速生长上存在差异，而在其他生态、形态和行为方面相似的趋同物种通常具有相似的垂肉异速生长比例关系。这些模式表明，垂肉的比例关系可能遵循与其他生物特征相同的模式，即在生态上不同的同域物种中进化出了一系列不同的特征。
