A supergene-controlling social structure in Alpine ants also affects the dispersal ability and fecundity of each sex.

Social organization, dispersal and fecundity coevolve, but whether they are genetically linked remains little known. Supergenes are prime candidates for coupling adaptive traits and mediating sex-specific trade-offs. Here, we test whether a supergene that controls social structure in also influences dispersal-related traits and fecundity within each sex. In this ant species, single-queen colonies contain only the ancestral supergene haplotype and produce queens and males, while multi-queen colonies contain the derived haplotype and produce queens, queens and males. By combining multiple experiments, we show that the haplotype induces phenotypes with higher dispersal potential and higher fecundity in both sexes. Specifically, queens, queens and males are more aerodynamic and more fecund than queens and males, respectively. Differences between and queens from the same colonies reveal a direct genetic effect of the supergene on dispersal-related traits and fecundity. The derived haplotype , associated with multi-queen colonies, produces queens and males with reduced dispersal abilities and lower fecundity. More broadly, similarities between the and systems reveal that supergenes play a major role in linking behavioural, morphological and physiological traits associated with intraspecific social polymorphisms.