Macromotives and microbehaviors: the social dimension of bacterial phenotypic variability

Bacterial phenotypic variability--the display of multiple distinct phenotypes in a genetically homogenous population of bacteria-emerges as an adaptive response to conflicting challenges. This creates an opportunity for social interactions which are able to dynamically redistribute cell fates within a community and to directly share the benefits of the different fates. While social interactions between cell fates can optimize community behavior, they also make the community vulnerable to exploitation. The aim of this review is to emphasize the social roles of phenotypic variability and introduce it as a communal rather than a single-cell property. Specifically, we present two prevalent perspectives on the forces shaping social interactions between cell fates--engineering optimality and social stability--and review recent works combining engineering, developmental and social evolution analyses in light of this distinction.