Cyclic dominance emerges from the evolution of two inter-linked cooperative behaviours in the social amoeba

Shota Shibasaki, Masakazu Shimada
2018 Proceedings of the Royal Society of London. Biological Sciences  
Evolution of cooperation has been one of the most important problems in sociobiology, and many researchers have revealed mechanisms that can facilitate the evolution of cooperation. However, most studies deal only with one cooperative behaviour, even though some organisms perform two or more cooperative behaviours. The social amoeba Dictyostelium discoideum performs two cooperative behaviours in starvation: fruiting body formation and macrocyst formation. Here, we constructed a model that
more » ... s these two behaviours, and we found that the two behaviours are maintained due to the emergence of cyclic dominance, although cooperation cannot evolve if only either two behaviours is performed. The common chemoattractant cyclic AMP is used in both fruiting body formation and macrocyst formation, providing a biological context for this coupling. Cyclic dominance emerges regardless of the existence of mating types or spatial structure in the model. In addition, cooperation can re-emerge in the population even after it goes extinct. These results indicate that the two cooperative behaviours of the social amoeba are maintained due to the common chemical signal that underlies both fruiting body formation and macrocyst formation. We demonstrate the importance of coupling multiple games when the underlying behaviours are associated with one another. 19 In fruiting body formation, cells first aggregate by responding to synchronously secreted cyclic 20 AMP (cAMP) [13] , and then, the aggregated cells form multicellular slugs and develop into fruiting 21
doi:10.1098/rspb.2018.0905 pmid:29925622 fatcat:njrwvz4nt5bkxmjlpzqtjxeay4