DISSERTATION RESEARCH: Postcopulatory Sexual Selection and Gametic Isolation in Stalk-Eyed Flies

这项研究涉及进化生物学中的两个主要领域：物种形成和性选择。物种形成--一个谱系分裂成两个谱系--是创造我们在世界上看到的令人难以置信的生物多样性的进化力量。自达尔文于1859年出版他的开创性著作以来，了解物种形成的驱动力一直是进化研究的主要目标。性选择是通过竞争配偶和配子而产生的进化力量。性选择可以在选择配偶、交配顺序甚至交配后的任何时候进行。在交配前，雄性为了接近雌性而竞争，雌性在雄性中选择。在交配后的情况下，雌性生殖道的形态和生理在多个雄性的精子中进行选择，而精子在雌性内部竞争获得配子。最近的研究表明，由于集中在受精事件上的巨大进化压力，交配后的性状进化得非常快。这在从昆虫到哺乳动物的许多分类群中都是如此。直到最近，研究人员才开始研究交配后特征的差异是否在物种形成中起到了因果作用。这种生殖隔离屏障被称为配子隔离。这个项目调查了最近分化的杆眼苍蝇种群中是否进化出了配对隔离。这些结果将提供对种群间配子隔离模式的洞察，以及配子隔离作为物种形成机制的相对重要性。一名博士生和至少一名本科生将接受培训。此外，这项研究的结果将通过海报和口头陈述以及同行评议的出版物进行传播。

This research addresses the intersection of two major fields in evolutionary biology: speciation and sexual selection. Speciation - the splitting of one lineage into two - is the evolutionary force responsible for creating the incredible diversity of life we see in the world. Understanding the driving forces underlying speciation has been a primary goal of evolutionary research since Darwin published his seminal book in 1859. Sexual Selection is the evolutionary force created by competition for mates and gametes. Sexual selection can act at any point during the selection of mates, the mating sequence and even after copulation. In the pre-copulatory context, males compete for access to females and females choose among males. In the post-copulatory context, female reproductive tract morphology and physiology choose among the sperm of multiple males while sperm compete within females for access to gametes. Recent work has shown that post-copulatory traits evolve extremely rapidly due to the immense evolutionary pressure focused on the fertilization event. This is true in a wide range of taxa, from insects to mammals.Only recently have researchers begun to investigate whether divergence in post-copulatory traits plays a causal role in speciation. This type of reproductive isolating barrier is termed Gametic Isolation. This project examines whether gametic isolation has evolved among recently diverged populations of stalk-eyed flies. The results will offer insight into both the patterns of gametic isolation among populations and the relative importance of gametic isolation as a mechanism of speciation. A PhD student and at least one undergraduate student will be trained. Additionally, the results of this research will be disseminated through poster and oral presentations and peer-reviewed publications.