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

标题：红背细尾鹩鹩的羽毛颜色多态性：机制和功能，作者：Michael S. webster合作者：Hubert Schwabl和Jordan karubian进化生物学的一个主要目标是解释物种内部和物种之间的生物多样性。许多物种在行为和形态上都表现出明显的表型变异，一种表型的个体与另一种表型的个体在外表和行为上都大不相同。例如，澳大利亚红背小鹪鹩（Malurus melanocephalus）的雄性有两种不同的类型：一些雄性繁殖时羽毛鲜艳，提供相对较少的亲代照顾，并寻求外交配，而另一些雄性则是神秘的颜色，提供较多的亲代照顾，并且似乎不寻求外交配。要理解这种表型多态性，需要理解产生它的机制以及创造和维持它的进化力量。在这个项目中，Webster等人将研究导致红背鹩莺多态性的激素/生理机制和进化力量。对激素水平变化的相关分析将与激素操纵实验相结合，以确定导致雄性采用一种或另一种羽毛类型的机制。此外，对野生和圈养鸟类的实验将用于彻底测试雄性是否会根据社会线索改变羽毛类型。在功能水平上，对野生鸟类的观察，结合野外实验和亲子遗传分析，将用于确定具有不同表型的雄性的总繁殖成功率。该项目将是第一个从机制和功能角度研究恒温脊椎动物复杂的种内多态性的项目之一。因此，该研究将作为理解其他吸热生物多态性的模型，也将作为研究自然现象的多元方法的模型。在这样做的过程中，这个项目将直接解决当前行为和进化生物学中的几个争议。具体而言，本研究将：(1)有助于更好地理解显着和多态性状的功能；(2)有助于阐明激素在羽毛颜色形成中的作用；(3)阐明社会行为与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.