Signals in the Dark: What factors select for the evolution of cooperation controlled by quorum sensing?

Quorum sensing is a ubiquitous strategy in which bacteria are able to sense the presence of others via the density of a secreted molecule. Vibrio harveyi is one such bacterial species that uses quorum sensing to control a public goods cooperation strategy. As with all cooperative strategies, this strategy is at risk of cheating organisms ousting cooperators. Using the platform Empirical, we first replicated the results from a wetlab experiment and then determined the effects of population structure and resource availability on the de novo evolution, short-term, and long-term stability of a quorum sensing-controlled public goods strategy. We found that environments that enabled pre-existing cooperators to remain stable were not always the same environments in which cooperation could evolve de novo. Specifically, cooperation was able to persist in the short term in semi-structured populations with low resource levels, but not be maintained over long evolutionary time scales.