Data from: No effect of environmental heterogeneity on the maintenance of genetic variation in wing shape in Drosophila melanogaster

Theory suggests that heterogeneous environments should maintain more
genetic variation within populations than homogeneous environments, yet
experimental evidence for this effect in quantitative traits has been
inconsistent. To examine the effect of heterogeneity on quantitative
genetic variation, we maintained replicate populations of Drosophila
melanogaster under treatments with constant temperatures, temporally
variable temperature, or spatially variable temperature with either
panmictic or limited migration. Despite observing differences in fitness
and divergence in several wing traits between the environments, we did not
find any differences in the additive genetic variance for any wing traits
among any of the treatments. Although we found an effect of gene flow
constraining adaptive divergence between cages in the limited migration
treatment, it did not tend to increase within-population genetic variance
relative to any of the other treatments. The lack of any clear and
repeatable patterns of response to heterogeneous vs. homogeneous
environments across several empirical studies suggests that a single
general mechanism for the maintenance of standing genetic variation is
unlikely; rather, the relative importance of putative mechanisms likely
varies considerably from one trait and ecological context to another.