Local adaptation and divergence in colour signal conspicuousness between monomorphic and polymorphic lineages in a lizard

Population differences in visual environment can lead to divergence in multiple components of animal coloration including signalling traits and colour patterns important for camouflage. Divergence may reflect selection imposed by different receivers (conspecifics, predators), which depends in turn on the location of the colour patch. We tested for local adaptation of two genetically and phenotypically divergent lineages of a rock-inhabiting lizard, Ctenophorus decresii, by comparing the visual contrast of colour patches to different receivers in native and non-native environments. The lineages differ most notably in male throat coloration, which is polymorphic in the northern lineage and monomorphic in the southern lineage, but also differ in dorsal and lateral coloration, which is visible to both conspecifics and potential predators. Using models of animal colour vision, we assessed whether lineage-specific throat, dorsal and lateral coloration enhanced conspicuousness to conspecifics,...不同种群所处的视觉环境存在差异，可促使动物体色的多个组成部分发生分化，其中既包含用于种内信号传递的性状，也涵盖对伪装功能至关重要的色彩模式。这类体色分化可能源于不同接收者（同种个体、捕食者）施加的选择压力，而该选择压力的强度又取决于色斑的具体位置。我们以栖息于岩石环境的蜥蜴德氏岩龙蜥（Ctenophorus decresii）的两个遗传与表型均存在分化的支系为研究对象，通过对比色斑在本土与非本土环境中对不同接收者的视觉对比度，检验其是否存在局部适应性。这两个支系最显著的差异在于雄性喉部体色：北部支系的喉部体色存在多态性，而南部支系则为单态性；此外二者在背部与体侧的体色上也存在差异，这类体色可被同种个体以及潜在捕食者所感知。我们借助动物色彩视觉模型，评估了支系特异性的喉部、背部及体侧体色是否能提升对同种个体的显眼程度……