Strategic investment explains patterns of cooperation and cheating in a microbe

• DOI: 10.1073/pnas.1716087115
• Publication Date: 2018-05-22T17:05:35Z
• Authors: Philip G. Madgwick; Balint Stewart; Laurence J. Belcher; Christopher R. L....; Jason B. Wolf
• Keywords: game theory; 0301 basic medicine; Conflict; conflict; Spores, Protozoan; Individuality; cooperation; /dk/atira/pure/subjectarea/asjc/1000; name=General; Biological Evolution; Models, Biological; Cooperation; 03 medical and health sciences; Game Theory; Cheating; kin selection; Dictyostelium; Kin selection; Cooperative Behavior; Game theory

SignificanceContributing to cooperation is costly, while its rewards are often available to all members of a social group. Therefore, cooperation is vulnerable to exploitation by individuals that do not contribute but nevertheless share the benefits. So why contribute to cooperation? This dilemma can be resolved if individuals modulate their ‟investment” into cooperation dependent on whether benefits go to relatives or nonrelatives, which maximizes the return on investment to their genes. To evaluate this idea, we derived a model for cooperative investment and tested its predictions using a social microbe that cooperatively builds a stalk to facilitate spore dispersal. We find that cooperative investment into stalk closely matches predictions, with strains strategically adjusting investment according to their relatedness to their group.