Spatial social dilemmas promote diversity

Area of Science:

• Evolutionary game theory
• Mathematical biology
• Population genetics

Background:

• Cooperative investments in social dilemmas can lead to diverse strategies in well-mixed populations.
• Understanding how spatial structure influences this diversity is crucial for ecological and evolutionary insights.

Purpose of the Study:

• To analyze the impact of spatial population structure on the diversification of cooperative strategies in social dilemmas.
• To compare evolutionary dynamics in structured versus well-mixed populations.

Main Methods:

• Utilized pair approximation to derive analytical expressions for invasion fitness in structured populations.
• Developed a spatial adaptive dynamics framework to predict evolutionary changes.
• Employed extensive individual-based simulations to validate analytical findings.

Main Results:

• Spatial structure significantly impacts evolutionary diversification, with varied effects.
• Standard spatial adaptive dynamics may suppress diversification, but simulations reveal new modes driven by mutation-structure interactions.
• Population structures alter invasion fitness, potentially opening new evolutionary pathways inaccessible by small mutations.

Conclusions:

• Spatial structure can promote diversification in social dilemmas, contrary to some theoretical predictions.
• New diversification mechanisms arise from the interplay of mutation size and spatial arrangement.
• Strong selection further enhances the diversifying effect of spatial structure.