Data from: Fine-scale spatial ecology drives kin selection relatedness among cooperating amoebae

Cooperation among microbes is important for traits as diverse as
antibiotic resistance, pathogen virulence, and sporulation. The
evolutionary stability of cooperation against “cheater” mutants depends
critically on the extent to which microbes interact with genetically
similar individuals. The causes of this genetic social structure in
natural microbial systems, however, are unknown. Here we show that social
structure among cooperative Dictyostelium amoebae is driven by the
population ecology of colonization, growth, and dispersal acting at
spatial scales as small as fruiting bodies themselves. Despite the fact
that amoebae disperse while grazing, all it takes to create substantial
genetic clonality within multicellular fruiting bodies is a few
millimeters distance between the cells colonizing a feeding site. Even
adjacent fruiting bodies can consist of different genotypes. Soil
populations of amoebae are sparse and patchily distributed at millimeter
scales. The fine-scale spatial structure of cells and genotypes can thus
account for the otherwise unexplained high genetic uniformity of spores in
fruiting bodies from natural substrates. These results show how a full
understanding of microbial cooperation requires understanding ecology and
social structure at the small spatial scales microbes themselves
experience.