Evolution of Coloration and Mate Preferences Along Environmental Gradients

在一些关系密切的物种之间繁殖的唯一障碍是雌性伴侣的偏好。导致雌性配偶偏好或它们所基于的雄性特征进化的因素(即，随着世代的变化)可能导致新物种的形成。科学家们刚刚开始了解环境在这一过程中的作用。孔雀鱼是一种原产于特立尼达的小型溪流鱼类，雌性更喜欢橙色斑点更大、更亮的雄性。橙色斑点包含两种类型的色素，一种是雄性可以合成的(Drosopterins)，另一种是它们必须从食物中获得的(类胡萝卜素)。孔雀鱼类胡萝卜素的主要来源是生长在溪流岩石上的藻类。更宽的溪流在森林树冠上形成了更大的缺口，因此获得了更多的阳光，并有更大的藻类作物。这个项目将研究森林树冠覆盖的溪流之间的差异如何影响雄性颜色和雌性配偶偏好的演变。这些方法将包括野外实验、实验室育种实验、颜色测量和生化分析。更广泛的目标是加深对环境如何影响配偶偏好及其偏好特征演变的理解。这项研究将有助于我们对生物多样性的了解。

The only barriers to reproduction between some closely related species are female mate preferences. Factors that cause female mate preferences, or the characteristics of males they are based on, to evolve (i.e., change over generations) can lead to the formation of new species. Scientists are just beginning to understand the role of the environment in this process. In guppies, a small stream-dwelling fish native to Trinidad, females prefer males with larger and "brighter" orange spots. The orange spots contain two types of pigments, one of which males can synthesize (drosopterins) and the other of which they must obtain from their food (carotenoids). The main source of carotenoids for guppies is algae, which grow on rocks in the stream. Wider streams make larger gaps in the forest canopy, and consequently receive more sunlight and have larger standing crops of algae. This project will examine how variation among streams in forest canopy cover affects the evolution of male coloration and female mate preferences. The methods will include field experiments, laboratory breeding experiments, color measurements, and biochemical analyses.The broader goal is to develop a deeper understanding of how the environment affects the evolution of mate preferences and the traits they favor. This study will contribute to our knowledge of biological diversity.