Credit: Ostrowski et al
Scenarios for the evolutionary dynamics of cheating behaviors. In the arms race (top), epidemics of cheating and resistance successively sweep through populations. In the stalemate (middle), cheating becomes endemic but does not take over the population. In the mutation and selection scenario (bottom), cheating mutations keep popping up but are quickly removed by selection. Different colors represent different alleles, or variants, of the social genes.