Genetic variation in male and female reproductive characters associated with sexual conflict in Drosophila melanogaster.

Recent studies have shown that elevated mating, courtship and seminal substances affect female fitness negatively in Drosophila melanogaster. It has also been shown that males vary with respect to these characters and that male harm to females correlates positively with components of male fitness. These results suggest that there is sexual conflict over the effect of such male characters. An important component of this scenario is that females have evolved counteradaptations to male harm, but so far there is limited evidence for this. Here I define female resistance as the ability to withstand an increased exposure to males. Across 10 genetically differentiated lines of D. melanogaster, I found genetic variation among females in the reduction of lifespan that followed from exposure to males of different durations. There was also genetic variation among males with regards to the degree to which they decrease the lifespan of their mates. These results suggest that genetic variation for female ability to endure male sexually antagonistic adaptations exists and may play an important role in male-female coevolution.