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.
