Adaptation and the Parliament of Genes

Our modern understanding of adaptation by natural selection rests on assumptions about genes working together to produce organisms. However, there is considerable evidence for selfish genetic elements that distort the behaviour of individuals to increase their own transmission. How can we reconcile these opposing notions? We use a combination of population genetics, agent-based simulation, and game theory to model the evolution of both selfish genetic elements and genes that could suppress their distortion. We found that: (1) suppressor genes are more likely to be favoured when selfish genetic elements cause greater distortion; (2) selection on selfish genetic elements favours the evolution of greater distortion, making them more likely to be suppressed. We found these same results when examining an abstract model designed to illuminate the general principles, and models for three specific scenarios: an X chromosome driver, an imprinted gene, and a bacterial plasmid. Our results suggest that selection on selfish genetic elements will often drive coevolution with suppressors in a way that removes the impact of genetic conflict at the level of the individual.