Plumage Color Polymorphism in Red-Backed Fairy-Wrens: Mechanism and Function

红背精灵的羽毛颜色多态：机制和功能PI：Michael S.WebsterCo-PI：Hubert Schwabl和Jordan Karubian进化生物学的一个主要目标是解释物种内和物种间的生物多样性。许多物种在行为和形态上都表现出明显的表型差异，一种表型的个体看起来和行为方式与另一种表型的个体非常不同。例如，澳大利亚红背仙鸦(Malurus Blackocephalus)的雄性有两种不同的类型：一些雄性繁殖时羽毛鲜艳，提供相对较少的父母照顾，并寻求双亲外交配；而另一些雄性则颜色隐晦，提供大量父母照顾，似乎不寻求双亲外交配。要理解这种表型多态，既需要了解产生它的机制，也需要了解创造和维持它的进化力量。在这个项目中，韦伯斯特等人。将研究红背仙鸦的荷尔蒙/生理机制以及导致多态的进化力量。荷尔蒙水平变化的相关分析将与荷尔蒙操纵实验相结合，以确定导致雄性采用一种或另一种羽毛类型的机制。此外，还将使用野生鸟类和圈养鸟类进行实验，以彻底测试雄性鸟类是否会根据社会提示改变羽毛类型。在功能水平上，对野生鸟类的观察，结合野外实验和亲子关系的遗传分析，将被用来确定具有不同表型的雄性的总体繁殖成功。该项目将是从机械学和功能角度研究吸热脊椎动物复杂的种内多态的第一个项目之一。因此，这项研究将成为理解其他吸热生物的多态现象的模式，也将成为研究自然现象的多元化方法的模式。通过这样做，这个项目将直接解决行为和进化生物学中当前的几个争议。具体地说，这项研究将：(1)更好地理解显着和多态性状的作用；(2)有助于阐明激素在羽毛颜色发育中的作用；(3)阐明社会行为和形态之间的机制联系。

Title: Plumage color polymorphism in red-backed fairy-wrens: Mechanism and functionPI: Michael S. WebsterCo-PI: Hubert Schwabl and Jordan KarubianOne primary goal of evolutionary biology is to explain biological diversity, both within and among species. Many species show pronounced phenotypic variation in both behavior and morphology, with individuals of one phenotype looking and behaving very differently from individuals of another phenotype. For example, males of the Australian red-backed fairy-wren (Malurus melanocephalus) are of two different types: some males breed in bright plumage, provide relatively little parental care, and seek extrapair copulations, whereas other males are cryptically colored, provide much parental care, and do not appear to seek extrapair copulations. An understanding of this sort of phenotypic polymorphism requires an understanding of both the mechanisms that produce it and the evolutionary forces that create and maintain it. In this project, Webster et al. will examine the hormonal/physiological mechanisms and also the evolutionary forces responsible for polymorphism in the red-backed fairy-wren. Correlational analyses of changes in hormone levels will be combined with a hormone manipulation experiment to determine the mechanisms that cause a male to adopt one plumage type or the other. In addition, experiments with wild and captive birds will be used to thoroughly test whether males change plumage type in response to social cues. At a functional level, observations of wild birds, combined with field experiments and genetic analyses of parentage, will be used to determine the total reproductive success of males with different phenotypes.This project will be among the first to examine a complex intraspecific polymorphism in an endothermic vertebrate from both mechanistic and functional perspectives. As such, the study will serve as a model for understanding polymorphism in other endothermic organisms, and also as a model for a pluralistic approach to the study of natural phenomena. In doing so, this project will directly address several current controversies in behavioral and evolutionary biology. Specifically, this study will: (1) lead to a better understanding of the function of conspicuous and polymorphic traits; (2) help clarify the role of hormones in the development of plumage color; and (3) elucidate the mechanistic connections between social behavior and morphology.