Cooperation, Conflict and the Evolution of Social Signals

引人注目的观赏特征，例如色彩缤纷的鸟类羽毛，通常被视为性选择的代名词。美洲黑顶鸡（American coot）的奇特雏鸟，拥有鲜艳的橙子羽毛，羽毛经过修饰，头上覆盖着五颜六色的裸露皮肤，这让我们不得不在更广泛的进化背景下考虑装饰性信号。先前的研究表明，父母的选择（父母对特定后代特征的偏爱）为美国黑鸭的后代提供了非常强大的自然选择，并提出了一个基本问题：为什么父母更喜欢后代？拟议中的研究将通过调查小鸡信号的功能来回答这个问题（即，它们对父母行为的影响），以及这些影响对父母繁殖成功的后果（即，（1）所生后代的数量和质量）。合作和冲突都可以塑造社会信号系统的进化-确定每一个的相对重要性仍然是进化生物学家的一个重要挑战，也是拟议研究的一个主要焦点。小鸡信号的实验操作（例如，羽毛颜色，票据颜色和皮肤颜色）将用于确定小鸡信号功能的机制和对父母和后代的后果。一个双因素的实验将进行调查小鸡信号和父母的战术中央食物分配（孵化的孵化率，后代竞争不对称的主要决定因素）之间的相互作用。这项研究将通过探索自然选择如何塑造信号发送者和接收者，以及这些适应性后果如何相互作用以产生一个综合的社会系统，从而全面了解社会信号系统的演变。在追求这些研究目标的同时，该项目还将为本科生提供密集的指导。九名学生将参与研究计划的各个方面-从规划田间季节，到设置田间实验，再到进行行为观察和数据管理和分析-并将获得科学调查的实践经验。

Striking ornamental traits such as colorful bird plumage are often viewed as synonymous with sexual selection. The bizarre chicks of the American coot, resplendent with their bright orange plumage of modified feathers and a head capped with colorful naked skin, challenge us to consider ornamental signals in a broader evolutionary context. Previous research revealed that parental choice (parental favoritism for particular offspring characteristics) provides extremely strong natural selection for ornamented offspring in American coots and raised a fundamental question: why do parents prefer ornamented offspring? The proposed research will answer this question by investigating how the chick signals function (i.e., their effects on parental behavior), and the consequences of these effects on the reproductive success of the parents (i.e., the number and quality of offspring produced). Both cooperation and conflict can shape the evolution of social signaling systems - determining the relative importance of each remains an important challenge for evolutionary biologists and is a major focus of the proposed research. Experimental manipulation of chick signals (e.g. plumage color, bill color, and skin color) will be used to determine both the mechanism of chick signal function and the consequences to parents and offspring. A two-factor experiment will be conducted to investigate the interaction between chick signals and parental tactics central to food allocation (degree of hatching asynchrony, the main determinant of offspring competitive asymmetries). The research will provide a comprehensive understanding of the evolution of a social signaling system by exploring how natural selection shapes both the signaler and the receiver, and how these fitness consequences interact to produce an integrated social system. While pursuing these research objectives, this project will also provide intensive mentoring of undergraduate students. Nine students will be involved in all aspects of the research program - from planning the field season, to setting up field experiments, to making behavioral observation and data management and analysis - and will gain hands-on experience with a scientific investigation.