The hidden cost of altruistic policing

Kin selection is the dominant paradigm to explain the evolution of cooperation and, worker policing, one of its most convincing examples. Here, workers aggress upon laying workers or consume their eggs to increase overall colony relatedness. However, policing presents an evolutionary paradox as those workers who police are simultaneously less likely to be laying workers (i.e. the traits are negatively correlated). Consider a population where all workers lay male eggs into which a policing mutant arises. The mutant will suppress a fraction of the laying workers and their eggs will be replaced by queen-laid ones. If the queen has multiply mated, the mutant will gain fitness by this action. Some proportion of eggs, however, will still be worker-laid and the mutant has functionally self-sterilized with regards to this pool of offspring. Such self-policing could be a strong selective force against the evolution of policing others. Here, we present several simulations to examine this dynamic and at what levels of selection policing is selected for.