Evolution of genetic and physiological mechanisms of cooperative behaviour

•Proximate mechanisms of cooperation can overcome conflicts of fitness interests.•Genetic, neural and endocrine cooperation mechanisms are phylogenetically conserved.•Functions of regulatory systems diverge between taxa.•Key mechanisms of cooperation show functional independence and modular evolution.

Emergence of cooperative behaviour requires the evolution of proximate mechanisms to overcome the conflict of fitness interests inherent in social interactions. Reciprocal trading and enforcement of help are means by which cooperation can ensue between social partners subject to conflicting fitness interests. We discuss potential routes to the evolution of mechanisms of cooperative behaviour, with a special focus on vertebrates. We emphasize that a stable social organization, the exertion of social control and the experience-based propensity to act cooperatively are fundamental building blocks of cooperation. Genetic, neural and endocrine mechanisms involved in the regulation of cooperative behaviour are apparently deeply conserved in the phylogenies of different taxonomic groups. At the same time, the functions of regulatory systems diverge enormously between taxa, revealing functional independence and modular evolution of key components at both genetic and physiological levels.