The role of selective extinction in promoting cooperation in a many demes model

• Published in: Journal of theoretical biology Vol. 613; p. 112212
• Main Author: Kroumi, Dhaker
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 07.10.2025
• Subjects: Animals; Biological Evolution; Cooperative Behavior; Diffusion approximation; Extinction, Biological; Extinction-recolonization Mathematics Subject Classification; Fixation probability; Humans; Identity by descent; Island model; Models, Biological; Population Dynamics; Primary 91A25; Prisoner Dilemma; Prisoner’s dilemma; Reproduction; Secondary 60J70; Diffusion approximation; Secondary 60J70; Prisoner’s dilemma; Island model; Primary 91A25; Identity by descent; Extinction-recolonization Mathematics Subject Classification; Fixation probability
• ISSN: 0022-5193; 1095-8541; 1095-8541
• DOI: 10.1016/j.jtbi.2025.112212

•Diffusion approximation captures evolutionary dynamics.,•Uniform extinction suppresses cooperation in structured populations.,•Targeted extinction can promote cooperation.,•Extinction rate’s impact depends on payoff asymmetry (T−R vs. P−S). This study investigates the evolution of cooperation in a deme-structured population where individuals interact via the Prisoner’s Dilemma. Reproduction is payoff-dependent, and demes contribute to a global migrant pool proportionally to their fecundity. Deme extinction occurs with a baseline probability plus an additional probability term that is proportional to the fraction of defectors in the deme, modulated by a parameter α. Extinct demes are then repopulated from the migrant pool. A two-timescale analysis, valid in the limit of a large number of demes, reveals that the system’s evolutionary dynamics are well-approximated by a continuous-time diffusion process. Using this diffusion approximation, we show that uniform extinction (α=0) suppresses cooperation. However, extinction targeting defector-dominated demes can significantly promote cooperation, establishing critical thresholds of α that determine when cooperation dominates. The study further explores how varying extinction rates and reproductive dynamics impact cooperation’s persistence and evolutionary success in structured populations.