Sex differences in dispersal syndrome are modulated by environment and evolution

Dispersal syndromes (i.e. suites of phenotypic correlates of dispersal) are potentially important determinants of local adaptation in populations. Species that exhibit sexual dimorphism in their life history or behaviour may exhibit sex-specific differences in their dispersal syndromes. Unfortunately, there is little empirical evidence of sex differences in dispersal syndromes and how they respond to environmental change or dispersal evolution. We investigated these issues using two same-generation studies and a long-term (greater than 70 generations) selection experiment on laboratory populations of Drosophila melanogaster. There was a marked difference between the dispersal syndromes of males and females, the extent of which was modulated by nutrition availability. Moreover, dispersal evolution via spatial sorting reversed the direction of dispersal × sex interaction in one trait (desiccation resistance), while eliminating the sex difference in another trait (body size). Thus, we show that sex differenc...