SO ENDS this short weekend looking at the difference between the agendas of sexual partners in fruit flies. Not only is the rate of evolution of proteins involved in sexual reproduction faster than somatic proteins, but the triggering of reproductive readiness in the two sexes is very different. The female gets massively changed. At least in fruit flies, the male and female are quite divergent biologically, behaviorally, and genetically, and continue to evolve in different but complementary trajectories.