Clever study shows how cooperative bacteria sanction — and therefore exclude — cheaters

ScienceDaily “Cooperating bacteria isolate cheaters”

This kind of study is where the field exploring how cooperation evolves should be headed: model predictions are verified by actual microbial microcosms, but the interactions of those microcosms are manipulated by genetically-engineering variation in behavior (what this article calls “synthetic ecology”). This approach helps overcome a common problem faced by evolutionary biologists: often, when we want to understand the adaptive value of a trait it is difficult to do so because all other variants have been purged by selection. By introducing cheating variants and different metabolic variants in this study, the investigators were able to cleverly demonstrate not just that metabolic mutualism can evolve between different strains of bacteria but also shed light on the mechanisms by which these mutualisms can be maintained in the face of cheating.