Genetic divergence in the Amarillo fish

对我们理解生物多样性至关重要的是，我们要评估种群分化和物种形成的原因。地理分离和适应不同的生态位是物种形成的最常见原因，但有人认为，性选择/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非常重要。最近，人们发现，一种墨西哥鱼类的男性和女性形态的极端差异，显示出地理上分离的种群之间几乎完全的性隔离。在实验室里，当让雌性在雄性之间做出选择时，它们通常会选择自己种群中的雄性，而不是其他种群中的雄性。我们建议抽样人口的这个物种和得分两种类型的遗传标记，以重建这个物种的进化历史，特别是分离成不同的，潜在的非杂交种群。有了这些数据，我们将能够评估a）行为特征是否比其他人更快地分化，B）雄性在种群之间的移动是否比雌性更快（这对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）如果雌性对与陌生雄性交配更挑剔，种群之间的一般遗传差异是否更大。这些结果将共同表明性选择是否会导致该物种内的分歧，并提供该物种内的遗传多样性数据，该物种属于濒危群体。

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.