Genetic divergence in the Amarillo fish

我们必须评估种群分化和物种形成的原因，这对我们理解生物多样性至关重要。地理上的分离和对不同生态位的适应是物种形成的最常见原因，但有人认为，性别选择/雌性配偶偏好和雄性行为的进化/在动物新物种的产生中可能是极其重要的。最近，人们发现，一种在雄性和雌性形态上存在极大差异的墨西哥鱼，在地理上分离的种群之间表现出几乎完全的性别隔离。当在实验室中让雌性在雄性之间进行选择时，她们通常会从自己的种群中选择雄性，而不是来自其他种群的雄性。我们建议对该物种的种群进行采样，并对两类遗传标记进行评分，以重建该物种的进化历史，特别是将其划分为不同的、潜在的非杂交种群。有了结果数据，我们将能够评估是否a)行为特征比其他特征分化更快，b)雄性比雌性更多地在种群之间移动(这对于雌性选择如何限制种群之间的基因流动的模型很重要)，以及c)如果雌性更挑剔与陌生雄性交配，那么种群之间的总体遗传差异是否更大。这些结果将表明性别选择是否会导致该物种内部的分化，并提供该物种内遗传多样性的数据，该物种属于濒危物种。

It is essential for our understanding of biodiversity that we assess the causes of population differentiation and speciation. Geographic separation and adaptation to different ecological niches are the most common causes of speciation, but it has been argued that sexual selection / the evolution of female mate preferences and male behaviour / can be extremely important in the generation of new species in animals. Recently it has been found that a species of Mexican fish with extreme differences in male and female morphology shows virtually complete sexual isolation between geographically disjunct populations. When females are given a choice between males in the laboratory they usually choose males from their own population over those from other populations. We propose sampling populations of this species and scoring two types of genetic marker to reconstruct the evolutionary history of this species, specifically the separation into different, potentially non-interbreeding populations. With the resultant data we will be able to assess if a) behavioural traits diverge more quickly than others b) males move between populations more than females (which is important to models of how female choice can limit gene flow between populations) and c) if general genetic divergence between populations is greater if females are fussier about mating with strange males. Together these results will indicate whether sexual selection causes divergence within this species, and provide data on the genetic diversity within this species, which belongs to an endangered group.