Pre-zygotic barriers to interbreeding have received an increasing amount o f attention during the past several decades. Emergent areas of interest include how novel sexual communication systems evolve, and intersexual conflict between sperm and the female reproductive tract. Here, I show for the first time that natural genetic variation between Drosophila simulans and D. mauritiana at a single genomic region can induce both
species-specific female choosiness and the male trait they are discriminating against. Additionally, there were two separate regions of the genome that were individually capable o f inducing this trait/preference combination, suggesting that trait/preference linkage may be widespread. In another study, I found that males ofPeromyscus may be using sperm cooperation as an adaptation to obtain fertilizations. In addition, I observed that in Peromyscus maniculatus, where females mate multiply, the females have longer oviducts than in the monogamous P. polionotus. The longer oviducts may sexually select for more compatible (e.g. conspecific) sperm through cryptic female choice
