Speaker
Description
Natural selection often operates simultaneously at multiple levels of biological organization, with evolutionary forces at each level potentially creating a tug-of-war between individual-level incentives to cheat and a collective incentive of maintaining cooperation. In this talk, we will discuss a stochastic framework for describing nested birth-death processes in group-structured populations with selection operating within and among competing groups, presenting simulations of the stochastic models and deriving ODE and PDE models that arise by successively taking the limit of an infinite number of groups and infinite group size. By comparing different possible update rules for individual-level and group-level replication events, we will be able to explore how forms of frequency-dependent competition at each level of selection can help shape the long-time support for cooperation by multilevel selection in both finite and infinite populations.
