Division of Evolutionary Biology, Zoological Institute, Technical University of Braunschweig, Spielmannstrasse 8, Braunschweig, Germany.
J Evol Biol. 2009 May;22(5):1046-56. doi: 10.1111/j.1420-9101.2009.01717.x.
The proximate functions of animal skin colour are difficult to assign as they can result from natural selection, sexual selection or neutral evolution under genetic drift. Most often colour patterns are thought to signal visual stimuli; so,their presence in subterranean taxa is perplexing. We evaluate the adaptive nature of colour patterns in nearly a third of all known species of caecilians, an order of amphibians most of which live in tropical soils and leaf litter. We found that certain colour pattern elements in caecilians can be explained based on characteristics concerning above-ground movement. Our study implies that certain caecilian colour patterns have convergently evolved under selection and we hypothesize their function most likely to be a synergy of aposematism and crypsis, related to periods when individuals move overground. In a wider context, our results suggest that very little exposure to daylight is required to evolve and maintain a varied array of colour patterns in animal skin.
动物皮肤颜色的直接功能很难确定，因为它们可能是自然选择、性选择或遗传漂变下的中性进化的结果。大多数情况下，颜色模式被认为是视觉刺激的信号;因此，它们在地下分类群中的存在令人费解。我们评估了近三分之一已知蚓螈物种的颜色模式的适应性，蚓螈是一种两栖动物，大多数生活在热带土壤和落叶层中。我们发现，蚓螈的某些颜色模式元素可以根据与地面上运动有关的特征来解释。我们的研究表明，某些蚓螈的颜色模式是在选择下趋同进化的，我们假设它们的功能最有可能是警戒和伪装的协同作用，与个体在地面上移动的时期有关。从更广泛的角度来看，我们的研究结果表明，动物皮肤中进化和维持多样化的颜色模式所需的日光照射很少。
