Genetic population structure in polygynous formica ants.

Genetic population structures, both mating and interaction structures, were investigated in three polygynous Formica ants by examining how genotype frequencies are distributed among the nests in their populations. The study is based on electrophoretically analysed enzyme polymorphisms. The patterns of genotypic variation among single-nest workers suggest that polygyny is functional in all the three species. The observed genotype frequencies indicate outbreeding within the study areas, and no spatial microdifferentiation in gene frequencies is detected. The coexistent gynes in nests of both F. transkaucasica and F. polyctena are genetically related to each other, and the same holds for worker nest mates. These results support the hypothesis that polygyny is favoured by kin selection. The lack of genetic relatedness among gyne nest mates in the highly polygynous F. aquilonia suggests that additional factors, such as mutualism or parental parasitism, are probably involved in the evolution of polygyny.