Speaker
Description
Biological functions of many cellular assemblages, ranging from multicellular organisms to microbial communities, rely on diversity among the composing units. Such division of labour is often seen through the lens of game theory, where the accent is posed on the success of different strategies in short-term competition (e.g. one cell type grows faster than another - like in cancer). Such conceptual model has consequences on our expectations for the evolutionary outcomes: costly collective functions should be wiped out by natural selection acting on individual cells. In this talk, I will discuss how viewing reproduction rates as the result of a game sidesteps several important features of the life cycles underpinning collective functions: the coexistence of multiple spatiotemporal scales, the context-dependence of interactions, and selection acting at the collective level. Population-level averages mask relevant processes whereby collective structures repeatedly self-organize. I will illustrate these concepts with models and observations on the eco-evolutionary dynamics of the social amoeba Dictyostelium discoideum, where the effects of interactions are time-dependent. I will end discussing how an externally imposed collective life cycle can drive the evolution of both mutualism and increased diversity.
