Cooperation evolution and self-regulation dynamics in metapopulation: Stage-equilibrium hypothesis

The cause, maintenance and significance of cooperation are the key to understand mutual altruism, one of the most important behavioral strategies in social animals. Differential models based on mean-field assumption and pair approximation and cellular automaton were built on metapopulation framework to reveal the effect of empty patches and multi-behavior strategies on persistence under habitat degradation. (1) The cooperators were always been excluded under mean-field assumption, showing that the coexistence of defective and cooperative behaviors is impossible in well-mixed population. (2) Metapopulation can survive even when colonization rate was lower than extinction rate, due to the compensation of cooperation rewards to extinction debt. (3) With the change of the temptation to defect and other parameters, metapopulation can be pure cooperators, pure defectors, and cooperator–defector coexistence (aggregated cooperators encircled by the defectors with relatively fixed borders). (4) Under habitat destruction, including patch isolation and habitat decay, metapopulation remains constant size through the self-regulation of cooperator–defector frequencies. The habitat improvement is always accompanied contradictorily with the behavioral degradation (more cheaters). Results and literature evidences lead to a stage-equilibrium hypothesis: multi-element system can maintain and stabilize its function and systematic level under environmental stress through the self-regulation of element proportions. It emphasizes the homeostatic utilitarian of diversity, besides narrowly and diffusely utilitarian and ethical impetration. This hypothesis was also compared with Gaia theory, niche construction, ecosystem engineering, and Baldwin effect.