Data from: Mosaic structure of native ant supercolonies

According to the inclusive fitness theory, some degree of positive
relatedness is required for the evolution and maintenance of altruism.
However, ant colonies are sometimes large interconnected networks of nests
which are genetically homogenous entities, causing a putative problem for
the theory. We studied spatial structure and genetic relatedness in two
supercolonies of the ant Formica exsecta, by using nuclear and
mitochondrial markers. We show that there may be multiple pathways to
supercolonial social organization leading to different spatial genetic
structures. One supercolony formed a genetically homogenous population
dominated by a single mtDNA haplotype, as expected if founded by a small
number of colonizers, followed by nest propagation by budding and
domination of the habitat patch. The other supercolony had several
haplotypes and the spatial genetic structure was a mosaic of nuclear and
mitochondrial clusters. Genetic diversity probably originated from
long-range dispersal, and the mosaic population structure is likely a
result of stochastic short-range dispersal of individuals. Such a mosaic
spatial structure is apparently discordant with the current knowledge
about the integrity of ant colonies. Relatedness was low in both
populations when estimated among nestmates, but increased significantly
when estimated among individuals sharing the same genetic cluster or
haplogroup. The latter association indicates the important historical role
of queen dispersal in the determination of the spatial genetic structure.