Résumé
Intralocus sexual conflict occurs when opposing selection pressures
operate on loci expressed in both sexes, constraining the evolution of
sexual dimorphism and displacing one or both sexes from their optimum. We
eliminated intralocus conflict in Drosophila melanogaster by limiting
transmission of all major chromosomes to males, thereby allowing them to
win the intersexual tug-of-war. Here we show that this male-limited (ML)
evolution treatment led to the evolution (in both sexes) of masculinized
wing morphology, body size, growth rate, wing loading, and allometry. In
addition to more male-like size and shape, ML evolution resulted in an
increase in developmental stability for males. However females expressing
ML chromosomes were less developmentally stable, suggesting that being
ontogenetically more male-like was disruptive to development. Sexual
selection over size and shape of the imago may explain the persistence of
substantial genetic variation in these characters and the ontogenetic
processes underlying them.