Probing the Interaction of Peripheral Sensory Tuning and Central Processing in Mate Choice

进化生物学的主要问题之一是个体和物种之间的生物多样性是如何产生的？回答这个问题将有助于我们了解基本的生物过程，如地球上生命的进化，并帮助我们确定如何最好地保护濒危物种，特别是在面临人类引发的气候变化时。在试图解释种群和物种如何进化时，达尔文是最早区分自然选择和性选择的人之一。自然选择是由于个体之间的生存能力和生殖能力的差异，而性选择是由获得配偶的能力的差异驱动的。我们认为，性选择导致了观察到的一些最夸张的特征，如大鹿角、极端的求偶仪式和鲜艳的色彩。性选择是如何导致这种多样性的？很容易理解这些极端性格在雄性身上的进化；据推测，它们之所以进化是因为雌性更喜欢与拥有最极端形式的交配信号的雄性交配。首先，更难解释女性对这些极端男性角色的偏好的进化，这在进化生物学中仍然是一个悬而未决的问题。孔雀鱼和亲缘关系密切的物种是研究女性对“艳丽”男性角色偏好进化的最佳系统之一。我的研究利用孔雀鱼的几个独特特征(多个密切相关的物种出现在相似的环境中，物种内雌性偏好和雄性着色模式的差异，很容易在实验室繁殖进行遗传实验等)，以确定决定雌性配偶选择的遗传和环境因素。我的研究计划结合了在南美的实地研究、实验室遗传学研究和现代分子方法。在这项拟议的研究中，我们将研究Opsins的表达，这是控制包括人类在内的脊椎动物视觉系统调节的基因。我们还将研究基因在大脑中的表达，以了解配偶选择的差异如何在这些“更高顺序”的过程中编码。这将是关于女性配偶选择的遗传学和环境控制的最完整的研究之一，并将使我们能够评估性选择在种群分化以及最终在生物多样性生产中的作用。

One of the main questions in evolutionary biology is how biological diversity between individuals and species is generated? Answering this question will help us understand fundamental biological processes, such the evolution of life on earth, and help us determine how best to conserve endangered species, especially when confronted with human-induced climate change. Darwin was one of the first to differentiate between natural and sexual selection when attempting to explain how populations and species evolve. Natural selection is due to differences between individuals in survivorship and reproductive capacity, while sexual selection is driven by differences in the ability to get mates. We believe that sexual selection has led to some of the most exaggerated characters observed, such as large antlers, extreme courtship rituals, and bright coloration. How has sexual selection led to this diversity? It is easy to understand the evolution of these extreme characters in males; presumably they have evolved because females prefer to mate with males having the most extreme form of these mating signals. It is more difficult to explain the evolution of the female preference for these extreme male characters in the first place, and this remains an unsolved question in evolutionary biology. The guppy and closely related species is one of the best systems to study the evolution of female preference for “showy” male characters. My research takes advantage of several unique characteristics of guppies (multiple closely related species occurring in similar environments, differences in female preferences and male coloration patterns within species, easily bred in the lab for genetic experiments, etc.), in order to determine the genetic and environmental factors that determine female mate choice. My research program combines field studies in South America, lab genetic studies, and modern molecular approaches. In the proposed research, we will study the expression of opsins, the genes that control the tuning of the visual system in vertebrates, including humans. We will also examine expression of genes in the brain, to understand how differences in mate choice may be coded in these “higher order” processes. This will be one of the most complete studies of the genetics and environmental control of female mate choice, and will allow us to evaluate the role of sexual selection in the divergence of populations and ultimately in the production of biological diversity.