Phylogenetic Relationships and the Evolution of Sexual Dimorphism in Chaenopsid Blennies

长期以来，科学家们一直对导致性别差异进化的因素感兴趣。对物种内这种进化机制的了解也提供了对物种差异的洞察，这反过来又有助于我们对生命多样性的理解。该项目将研究木瓜鱼的性别差异的进化，木瓜鱼是一类热带海洋盲目鱼类。先前对珊瑚属的研究表明，雄性和雌性的许多差异是在单个事件中进化出来的，在这个事件中，雌性的发育被截断了。发育时间的类似变化在其他生物体中也是已知的，但很少与性别差异有关。导致这种分化的确切发育机制，无论是雌性发育放缓还是早期停止，将通过描述这些物种和相关物种的两性发育来确定。这种形态变化在这些鱼类生态中的作用将通过测试雌性鱼类栖息地利用的假设行为变化来研究。由一种性别引起的栖息地变化的记录很少，这是导致性别差异进化的一个重要原因，但最近被忽视了。这些结果的普适性将在同样具有二态的木瓜属Emblemaria的类似研究中得到检验。这项研究在整合系统学、发育生物学和行为生态学研究性别差异方面是独一无二的。

Scientists have long been interested in the factors responsible for the evolution of differences in the sexes. Knowledge of such mechanisms of evolution within species also provides insight into the divergence of species which in turn contributes to our understanding of the diversification of life. This project will study the evolution of sex differences in chaenopsid fishes, a group of tropical marine blennioid fishes. Prior research on the genus Coralliozetus has revealed that many of the differences in males and females evolved in a single event in which the development of females became truncated. Similar changes in the timing of development are known for other organisms, yet have rarely been implicated in the divergence of the sexes. The precise developmental mechanisms responsible for this divergence, whether a slowing or an early cessation of development in females, will be determined by describing the development in both sexes of these and related species. The role of this morphological change in the ecology of these fishes will be studied by testing a hypothesized behavioral shift in habitat use of females. Habitat shifts by one sex are poorly documented and represent an important, but recently overlooked, cause for the evolution of sex differences. The generality of these results will be tested in a similar study on the equally dimorphic chaenopsid genus Emblemaria. This research is unique in integrating systematics, developmental biology and behavioral ecology in the study of sex differences.