The common fruit fly (Drosophila melanogaster) has been used as a model system to study antagonistic coevolution between the sexes for the last 25 years. In this seminar I describe my lab's use "laboratory island analysis" and the construction of synthetic female resistance genes to tease apart the costs and benefits of male-female interactions from the female's perspective. These experiments were done to evaluate whether or not many of the apparent harmful effects of males on their mates are compensated by genetic benefits associated with increased quality offspring. Lastly, I describe my lab's use of genome-wide cytogenetic cloning to measure ongoing antagonistic coevolution between the sexes.