NSFDEB-NERC: Ecological Genomics of Adaptive Polymorphism

解释具有生态重要性的性状的高度遗传多样性是进化生物学的一个基本问题。个体在基因水平上差异巨大，甚至在当地人群中也是如此，我们不明白其中的原因。最近的研究表明，稀有类型的优势是维持许多物种遗传变异的关键因素，但我们对这一过程实际上是如何在野外展开的了解很少。为了解决这一差距，我们需要(1)了解生态和社会相互作用如何促进或侵蚀遗传多样性，以及(2)将生物之间的这些相互作用直接与调节这些相互作用的特征所在的基因联系起来。这个项目将把特立尼达孔雀鱼的遗传多样性特征与塑造其进化的生态和社会互动，以及塑造这种多样性的潜在基因联系起来。我们之前的工作表明，与捕食者和潜在配偶的互动都有利于该物种稀有的颜色模式。为了确定哪个过程最有责任促进多样性，我们将收集关于多个自然种群的捕食风险和交配行为的数据，并将这些数据与颜色模式中基于遗传的多样性程度联系起来。然后，使用遗传多样性不同的种群和密切相关的物种，我们将使用全基因组DNA测序来识别控制这种高度可变的特征的基因。这将使我们能够确定在平衡选择的情况下，生态和分子过程如何相互作用来促进或限制进化。最后，我们将通过实时观察具有不同择偶机会的实验种群的进化，直接测试潜在配偶之间的互动可以维持该物种的多样性的想法。

Accounting for high genetic diversity in ecologically-important traits is a fundamental problem in evolutionary biology. Individuals vary enormously at the genetic level, even within local populations, and we do not understand why. Recent work implicates an advantage to rare types as a critical factor maintaining genetic variation in many species, but we have little understanding of how this process actually unfolds in the wild. To address this gap, we need to (1) understand how ecological and social interactions promote or erode genetic diversity, and (2) link these interactions among organisms directly to the genes underlying the traits that mediate these interactions. This project will link a genetically diverse trait in the Trinidad guppy (Poecilia reticulata) to the ecological and social interactions that shape its evolution, and to the underlying genes that shape this diversity. Our previous work indicates that interactions with predators and with potential mates both favour rare colour patterns in this species. To determine which of the processes is most responsible for promoting diversity, we will collect data on predation risk and mating behaviour in multiple natural populations and relate these data to the degree of genetically-based diversity in colour patterns. Then, using populations and closely related species that vary in their genetic diversity, we will use whole-genome DNA sequencing to identify genes that control this highly variable trait. This will allow us to determine how ecological and molecular processes interact to promote or constrain evolution under balancing selection. Finally, we will directly test the idea that interactions between potential mates can maintain diversity in this species by observing evolution in real time in experimental populations with different opportunities for mate choice.