Figure 2: Relationship between phylogenetic distance and defector inhibition.

Effect of mean genetic distance between the defector and the community of cooperating bacteria on the growth inhibition of the model defector Pseudomonas fluorescens CHA0ΔgacS by cell-free supernatant of a 48-h-old cooperator cultures varying in mean genetic distance to the defector (GLM, R²=0.44, P<0.001). Inhibition was expressed as the growth reduction compared with control, normalized by the growth reduction of the wild-type background genotype CHA0. Note that to improve the robustness of the prediction, 96 communities were tested instead of the 48 used in the competition experiment. Symbol shading shows the richness of the different communities, ranging from white (monocultures) to black (eight genotypes).