Cross-sex genetic covariances limit the evolvability of wing-shape within and among species of Drosophila

The independent evolution of males and females is potentially constrained by both sexes inheriting the same alleles from their parents. This genetic constraint can limit the evolvability of complex traits; however, there are few studies of multivariate evolution that incorporate cross-sex genetic covariances in their predictions. Drosophila wing-shape has emerged as a model high-dimensional phenotype; wing-shape is highly evolvable in contemporary populations, and yet perplexingly stable across phylogenetic timescales. Here we show that cross-sex covariances in D. melanogaster, given by the B-matrix, may considerably bias wing-shape evolution. Using random skewers, we show that B would constrain the response to antagonistic selection by 90%, but would double the response to concordant selection. Both cross-sex within-trait and cross-sex cross-trait covariances determined the response to antagonistic selection, but only cross-sex within-trait covariances facilitated the response to con...