I am an evolutionary geneticist interested in understanding how reproductive traits evolve and function at a mechanistic level. A core interest is in evaluating the potential of sexual selection and sexual conflict for driving evolutionary change and in understanding the underlying mechanisms involved. Fruitflies provide an exceptionally good model, with relevance to pest control, for the study of sexual conflict and sexual selection. We have studied in detail the actions of seminal fluid proteins, which evolve at exceptionally high rates and have striking, fitness-related functions.