title: Games of multicellularity.
abstract: Evolutionary game dynamics are often studied in the context of different population structures. Here we propose a new population structure that is inspired by simple multicellular life forms. In our model, cells reproduce but can stay together after reproduction. They reach complexes of a certain size, n, before producing single cells again. The cells within a complex derive payoff from an evolutionary game by interacting with each other. The reproductive rate of cells is proportional to their payoff. We consider all two-strategy games. We study deterministic evolutionary dynamics with mutations, and derive exact conditions for selection to favor one strategy over another. Our main result has the same symmetry as the well-known sigma condition, which has been proven for stochastic game dynamics and weak selection. For a maximum complex size of n=2 our result holds for any intensity of selection. For n≥3 it holds for weak selection. As specific examples we study the prisoner's dilemma and hawk-dove games. Our model advances theoretical work on multicellularity by allowing for frequency-dependent interactions within groups.
authors.affiliation: Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138, USA. Electronic address: kkavehma@gmail.com.
authors.forename: Kamran
authors.initials: K
authors.lastname: Kaveh
authors.affiliation: Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; Department of Mathematics, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Carl
authors.initials: C
authors.lastname: Veller
authors.affiliation: Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; Department of Mathematics, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Nowak
mesh_terms: D049109:Cell Proliferation; D002477:Cells / Q000378:metabolism*; D003299:Cooperative Behavior; D005716:Game Theory; D008954:Models, Biological; D059645:Mutation Rate; D009716:Numerical Analysis, Computer-Assisted; D010641:Phenotype
keywords: Complexity; Cooperation; Evolution of multicellularity; Evolutionary game theory