Medina Iliana, Vega-Trejo Regina, Wallenius Thomas, Symonds Matthew R E, Stuart-Fox Devi
School of BioSciences University of Melbourne Melbourne Victoria 3010 Australia.
Division of Ecology and Evolution Australian National University Acton Australian Capital Territory 0200 Australia.
Evol Lett. 2019 Dec 12;4(1):34-43. doi: 10.1002/evl3.149. eCollection 2020 Feb.
Many animals undergo complete metamorphosis, where larval forms change abruptly in adulthood. Color change during ontogeny is common, but there is little understanding of evolutionary patterns in these changes. Here, we use data on larval and adult color for 246 butterfly species (61% of all species in Australia) to test whether the evolution of color is coupled between life stages. We show that adults are more variable in color across species than caterpillars and that male adult color has lower phylogenetic signal. These results suggest that sexual selection is driving color diversity in male adult butterflies at a broad scale. Moreover, color similarities between species at the larval stage do not predict color similarities at the adult stage, indicating that color evolution is decoupled between young and adult forms. Most species transition from cryptic coloration as caterpillars to conspicuous coloration as adults, but even species with conspicuous caterpillars change to different conspicuous colors as adults. The use of high-contrast coloration is correlated with body size in caterpillars but not adults. Taken together, our results suggest a change in the relative importance of different selective pressures at different life stages, resulting in the evolutionary decoupling of coloration through ontogeny.
许多动物会经历完全变态，幼虫形态在成年期会发生突然变化。个体发育过程中的颜色变化很常见，但人们对这些变化的进化模式了解甚少。在这里，我们利用246种蝴蝶（占澳大利亚所有蝴蝶种类的61%）幼虫和成虫颜色的数据，来测试颜色的进化在不同生命阶段之间是否存在关联。我们发现，成虫在物种间的颜色变化比毛虫更大，并且雄性成虫颜色的系统发育信号更低。这些结果表明，性选择在广泛范围内推动了雄性成年蝴蝶的颜色多样性。此外，幼虫阶段物种之间的颜色相似性并不能预测成虫阶段的颜色相似性，这表明颜色进化在幼虫和成虫形态之间是解耦的。大多数物种从毛虫阶段的保护色转变为成虫阶段的显眼颜色，但即使是毛虫颜色显眼的物种，成虫阶段也会变成不同的显眼颜色。毛虫中高对比度颜色的使用与体型相关，但成虫则不然。综合来看，我们的结果表明，不同生命阶段不同选择压力的相对重要性发生了变化，导致了个体发育过程中颜色的进化解耦。
