Dissertation Research: Phenotypic Integration of Adaptive Traits in Junco Hyemalis

许多物种的雄性利用多种观赏特征和行为来竞争和吸引配偶。如果这些相互作用决定了交配成功，那么选择可能会导致遗传整合的一整套性别特征和行为的进化，也就是所谓的交配表型。由于激素可以协调一系列性状的表达，它们可能在稳定这些交配表型方面发挥核心作用。这项研究考察了一种常见的鸣禽--黑眼金丝雀的交配表型的进化。将测量用于获取配偶的形态(大小和羽毛)、性激素睾酮和由睾酮调节的性行为之间的相关性。当前选择在维持这些相关性方面的作用将通过将性状组合与交配成功的遗传测量相关联来量化。实验将检验睾丸激素是否通过对形态的直接发育影响来稳定交配表型。这项研究应该有助于更好地理解一组功能相关性状的进化，并可能提出荷尔蒙在维持整合方面的重要作用。所有工作都将涉及本科生的广泛参与，既有研究助理，也有合作者。将鼓励本科生开发与这项工作相关的独立项目。

Males of many species use multiple ornamental traits and behaviors to compete for and attract mates. If these interact to determine mating success, selection may lead to the evolution of genetically integrated suites of sexual traits and behaviors, known as mating phenotypes. Because hormones can coordinate the expression of suites of traits, they may play a central role in stabilizing these mating phenotypes. This study examines the evolution of the mating phenotype in a common songbird, the dark-eyed junco. Correlations will be measured between morphology used in acquiring mates (size and plumage), the sexual hormone testosterone, and the sexual behaviors mediated by testosterone. The role of current selection in maintaining these correlations will be quantified by associating trait combinations with genetic measurements of mating success. Experiments will examine whether testosterone acts to stabilize the mating phenotype by direct developmental effects on morphology. This research should lead to a greater understanding of the evolution of groups of functionally related traits and may suggest important roles for hormones in maintaining integration. All work will involve the extensive participation of undergraduates, both as research assistants and collaborators. Undergraduates will be encouraged to develop their own independent projects related to this work.