Phylogenies and physiological processes--the evolution of sexual dimorphism in Southeast Asian frogs

There are a number of species of Southeast Asian Rana that are characterized by an unusual suite of sexually dimorphic features and derived reproductive modes. These frogs lack the usual secondary sexual characteristics of ranid frogs: nuptial pads, vocal sacs, and enlarged flexor muscles. Secondary sexual characteristics in frogs are under androgenic control. Phylogenetic analyses using morphological and molecular data indicate that a drop in androgen level and/or a shift in androgen sensitivity may have been involved in the evolution of male parental care and the loss of the common suite of secondary sexual characteristics in these Asian frogs. Phylogenetic analyses also provide important information on experimental design by indicating the most appropriate taxa to use in the exploration of physiological processes controlling the expression of sexual dimorphism. This work is an example of how emergent properties from phylogenetic analyses can be used to formulate and test hypotheses o...东南亚蛙属（Rana）存在多个物种，其特征为具备一套非同寻常的两性异形特征以及衍生的繁殖模式。这类蛙不具备蛙科物种常见的第二性征：婚垫、声囊以及膨大的屈肌。蛙类的第二性征受雄激素调控。结合形态学与分子数据开展的系统发育分析表明，雄激素水平下降和/或雄激素敏感性改变，可能参与了这类亚洲蛙类雄性育幼行为的演化，以及其常见第二性征的丢失过程。系统发育分析还能为实验设计提供重要参考：它能指明在探究调控两性异形表达的生理过程时，最适合选用的分类群。本研究即为一例，展示了如何利用系统发育分析得出的涌现属性来构建并验证假说……