Evolution of worker policing

TL;DR

This paper provides a mathematical analysis of the evolutionary dynamics of worker policing in insect societies, challenging traditional relatedness-based explanations and deriving precise conditions for policing evolution.

Contribution

It introduces a population genetics model that accounts for dominant and recessive mutations, and refines understanding of when worker policing evolves.

Findings

Policing evolves if the queen mates with more than two males under traditional views.

Small changes in colony efficiency can affect the robustness of relatedness-based arguments.

The model identifies conditions for invasion and stability of policing alleles.

Abstract

Workers in insect societies are sometimes observed to kill male eggs of other workers, a phenomenon known as worker policing. We perform a mathematical analysis of the evolutionary dynamics of policing. We investigate the selective forces behind policing for both dominant and recessive mutations for different numbers of matings of the queen. The traditional, relatedness-based argument suggests that policing evolves if the queen mates with more than two males, but does not evolve if the queen mates with a single male. We derive precise conditions for the invasion and stability of policing alleles. We find that the relatedness-based argument is not robust with respect to small changes in colony efficiency caused by policing. We also calculate evolutionarily singular strategies and determine when they are evolutionarily stable. We use a population genetics approach that applies to dominant or recessive mutations of any effect size.