DISSERTATION RESEARCH: Female ornamentation in the White-shouldered Fairywren: Proximate mechanisms and adaptive function

长久以来，艳丽的特征或装饰吸引了博物学家和进化生物学家的想象力。一种选择理论为雄性颜色或纹饰的变化提供了有力的解释，即雌性在无数代中选择越来越精致的雄性的过程。相比之下，女性观赏色彩的演变受到的关注相对较少，并且不能直观地用现有的理论来解释。新几内亚的白肩鹪鹩（Malurus alboscapulatus）是一种不寻常的鸟类，在不同的种群中，雌性的颜色不同，而雄性的羽毛保持不变。实验证据表明，女性身上更多的装饰颜色与更高的攻击性和更高的睾丸激素水平有关。然而，导致该物种出现雌性纹饰的行为和潜在过程之间的联系尚不清楚。这项研究旨在确定雄性和雌性细尾鹩莺产生纹饰的基因。这项研究解决了进化生物学的一个核心目标，即从独特的女性视角出发，确定产生特定外表的潜在机制。了解生物多样性产生模式的过程将传达给我们在新几内亚研究地点的当地社区和新奥尔良当地学龄儿童。进化生物学的一个当代目标是了解控制表型变异的基因组变化以及基因组变异如何产生性状多样性。研究人员将使用高通量测序技术来探索白肩鹪鹩羽毛变异的潜在遗传控制。他们有两个互补的目标：使用全基因组重测序来识别可能处于选择状态的基因组区域，并使用RNA测序来测试不同女性表型之间基因表达的差异。该研究将通过测试女性装饰物的变化如何在机械水平上产生的假设，从而促进对性别特异性颜色进化的理解，然后可以将研究人员收集的有关该特征当前适应功能的数据置于背景中。这个系统的优势在于，它提供了一个比较女性装饰物变化的机会，而不是比较更常见的观察和更好研究的男性特征变化。女性装饰物不仅受到作用于性状的选择力的影响，而且还受到产生表型的遗传机制的影响。拟议的遗传工作将建立在对该物种的先前研究的基础上，以提供对雌性纹饰的进化和功能的广泛理解，结合野外观察，实验操作和实验室技术。在这样做的过程中，这项研究有望对精心设计的女性颜色的近似基础和最终结果提供全面的了解。

Showy traits, or ornaments, have long captured the imagination of naturalists and evolutionary biologists. One theory of selection provides a robust explanation for variation in male coloration, or ornamentation, through the process of females choosing increasingly elaborate males over numerous generations. In contrast, the evolution of female ornamental coloration has received comparatively little attention, and is not intuitively explained using current theory. The White-shouldered Fairywren (Malurus alboscapulatus) of New Guinea is an unusual species of bird in which female coloration varies across populations, while male plumage remains constant. Experimental evidence suggests that more ornamented coloration in females is associated with heightened aggression and increased levels of testosterone. However, the connection between behavior and the underlying process that has led to the appearance of female ornamentation in this species remain unclear. This research aims to determine what genes are responsible in male and female fairywrens for producing ornamentation. The research addresses a core goal in evolutionary biology in identifying the underlying mechanisms that are responsible for generating specific appearances, but from a uniquely female-perspective approach. Understanding the processes involved in generating patterns of biodiversity will be communicated to local communities at our study sites in New Guinea and to local school aged children in New Orleans. A contemporary goal of evolutionary biology is to understand the genomic changes that control phenotypic variation and how genomic variation generates diversity in traits. The investigators will use high throughput sequencing techniques to explore the underlying genetic control of plumage variation in the White-shouldered Fairywren. They have two complementary goals: to use whole genome resequencing to identify regions of the genome that may be under selection and to use RNA sequencing to test for differences in gene expression between distinct female phenotypes. The study will advance the understanding of the evolution of sex-specific coloration by testing hypotheses for how changes in female ornaments may arise on a mechanistic level, which can then be contextualized with data the researchers have gathered on current adaptive function of the trait. The strength of this system is that it presents an opportunity to compare variation in female ornaments, rather than the more commonly observed and better studied variation in male traits. Female ornaments are influenced not only by selective forces acting on the traits, but also by the genetic mechanisms that produce the phenotype. The proposed genetic work will build on prior research in this species to provide a broad understanding of the evolution and function of female ornamentation that integrates field observation, experimental manipulation, and laboratory techniques. In doing so, the research is expected to provide a comprehensive understanding of both the proximate basis for and ultimate consequences of elaborate female coloration.