Bell R C, Webster G N, Whiting M J
Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA.
Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
J Evol Biol. 2017 Dec;30(12):2104-2115. doi: 10.1111/jeb.13170. Epub 2017 Sep 19.
Dynamic sexual dichromatism is a temporary colour change between the sexes and has evolved independently in a wide range of anurans, many of which are explosive breeders wherein males physically compete for access to females. Behavioural studies in a few species indicate that dynamic dichromatism functions as a visual signal in large breeding aggregations; however, the prevalence of this trait and the social and environmental factors underlying its expression are poorly understood. We compiled a database of 178 anurans with dynamic dichromatism that include representatives from 15 families and subfamilies. Dynamic dichromatism is common in two of the three subfamilies of hylid treefrogs. Phylogenetic comparative analyses of 355 hylid species (of which 95 display dynamic dichromatism) reveal high transition rates between dynamic dichromatism, ontogenetic (permanent) dichromatism and monochromatism reflecting the high evolutionary lability of this trait. Correlated evolution in hylids between dynamic dichromatism and forming large breeding aggregations indicates that the evolution of large breeding aggregations precedes the evolution of dynamic dichromatism. Multivariate phylogenetic logistic regression recovers the interaction between biogeographic distribution and forming breeding aggregations as a significant predictor of dynamic dichromatism in hylids. Accounting for macroecological differences between temperate and tropical regions, such as seasonality and the availability of breeding sites, may improve our understanding of ecological contexts in which dynamic dichromatism is likely to arise in tropical lineages and why it is retained in some temperate species and lost in others.
动态两性异色现象是指两性之间的一种临时性颜色变化，在广泛的无尾目动物中独立进化，其中许多是爆发式繁殖者，雄性会为接近雌性而进行身体竞争。对少数物种的行为研究表明，动态异色现象在大型繁殖群体中作为一种视觉信号发挥作用；然而，这种特征的普遍性以及其表现背后的社会和环境因素却鲜为人知。我们编制了一个包含178种具有动态异色现象的无尾目动物的数据库，其中包括来自15个科和亚科的代表物种。动态异色现象在雨蛙科三个亚科中的两个亚科中很常见。对355种雨蛙科物种（其中95种表现出动态异色现象）的系统发育比较分析表明，动态异色现象、个体发育（永久性）异色现象和单色现象之间的转变率很高，这反映了该特征具有高度的进化不稳定性。雨蛙科中动态异色现象与形成大型繁殖群体之间的相关进化表明，大型繁殖群体的进化先于动态异色现象的进化。多变量系统发育逻辑回归分析发现，生物地理分布与形成繁殖群体之间的相互作用是雨蛙科动态异色现象的一个重要预测因素。考虑到温带和热带地区之间的宏观生态差异，如季节性和繁殖地点的可用性，可能会增进我们对热带谱系中动态异色现象可能出现的生态背景的理解，以及为什么它在一些温带物种中保留而在另一些物种中消失。
