Emergence of cooperation in patchy habitat with mortality and colonization based on various 2 × 2 games

A multi-agent simulation model emulating the dynamic processes of an animal species' patchy habitat with mortality and colonization was established. The model, revised from Zhang et al. (2005), can deal with a variety of 2 × 2 game structures including the Prisoner's Dilemma (PD). When a higher mortality is assumed, the defect-agent fraction considerably decreases in a game structure with heavy dilemma (including the PD). This is because agents try to survive by forming cooperative clusters (C-cluster) to overcome the dilemma. This implies that cooperation easily emerges when the mortality process is more influential on the agent's adaptation than colonization, which seems consistent with Hauert's (2006) study. This situation increases the fraction of cooperative agents against the empty fraction in a larger number of link structures, which can easily build a C-cluster.