Abstract：
Common wall lizards (Podarcis muralis) in Italy show a striking variation in body coloration across the landscape, with highly exaggerated black and green colors in hot and dry climates and brown and white colors in cool and wet climates. Males are more intensely colored than females, and previous work has suggested that the maintenance of variation in coloration across the landscape reflects climatic effects on the strength of male-male competition, and through this sexual selection. However climatic effects on the intensity of male-male competition would need to be exceptionally strong to fully explain the geographic patterns of color variation. Thus, additional processes may contribute to the maintenance of color variation. Here we test the hypothesis that selection for green and black ornamentation in the context of male-male competition is opposed by selection against ornamentation because the genes involved in the regulation of coloration have pleiotropic effects on thermal physiology, such that ornamentation is selected against in cool climates. Field observations revealed no association between body coloration and microhabitat use or field active body temperatures. Consistent with these field data, lizards at the extreme ends of the phenotypic distribution for body coloration did not show any differences in critical minimum temperature, preferred body temperature, temperature-dependent metabolic rate, or evaporative water loss when tested in the laboratory. Combined, these results provide no evidence that genes that underlie sexual ornamentation are selected against in cool climate because of pleiotropic effects on thermal biology.
摘要：
意大利常见的墙蜥蜴（Podarcismuralis）在整个景观中表现出惊人的身体颜色变化，在炎热和干燥的气候中具有高度夸张的黑色和绿色，在凉爽和潮湿的气候中具有棕色和白色。雄性比雌性颜色更浓烈，以前的工作表明，维持整个景观的颜色变化反映了气候对男性-男性竞争强度的影响，通过这种性选择。然而，气候对男性-男性竞争强度的影响需要非常强烈，才能充分解释颜色变化的地理模式。因此，额外的过程可能有助于保持颜色的变化。在这里，我们检验了以下假设：在男性与男性竞争的背景下，绿色和黑色装饰的选择与装饰的选择相反，因为参与着色调节的基因对热生理具有多效性作用，这样在凉爽的气候下选择装饰。现场观察显示，身体颜色与微生境的使用或野外活动体温之间没有关联。与这些现场数据一致，蜥蜴在身体颜色的表型分布的极端没有显示出临界最低温度的任何差异，首选体温，温度依赖性代谢率，或在实验室测试时蒸发水分损失。合并,这些结果没有提供证据表明，由于对热生物学的多效性作用，在凉爽的气候中选择了构成性装饰的基因。
