title: The limits of weak selection and large population size in evolutionary game theory.
abstract: Evolutionary game theory is a mathematical approach to studying how social behaviors evolve. In many recent works, evolutionary competition between strategies is modeled as a stochastic process in a finite population. In this context, two limits are both mathematically convenient and biologically relevant: weak selection and large population size. These limits can be combined in different ways, leading to potentially different results. We consider two orderings: the [Formula: see text] limit, in which weak selection is applied before the large population limit, and the [Formula: see text] limit, in which the order is reversed. Formal mathematical definitions of the [Formula: see text] and [Formula: see text] limits are provided. Applying these definitions to the Moran process of evolutionary game theory, we obtain asymptotic expressions for fixation probability and conditions for success in these limits. We find that the asymptotic expressions for fixation probability, and the conditions for a strategy to be favored over a neutral mutation, are different in the [Formula: see text] and [Formula: see text] limits. However, the ordering of limits does not affect the conditions for one strategy to be favored over another.
authors.affiliation: Department of Mathematics, Emmanuel College, 400 Fenway, Boston, MA, 02115, USA. samplec@emmanuel.edu.
authors.forename: Christine
authors.identifier: 0000-0002-5874-2256
authors.initials: C
authors.lastname: Sample
authors.affiliation: Department of Mathematics, Emmanuel College, 400 Fenway, Boston, MA, 02115, USA.|Program for Evolutionary Dynamics, Harvard University, One Brattle Square, Cambridge, MA, 02138, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Allen
mesh_terms: D005075:Biological Evolution; D005716:Game Theory; D006801:Humans; D055641:Mathematical Concepts; D008954:Models, Biological; D009154:Mutation; D011156:Population Density; D012641:Selection, Genetic; D012919:Social Behavior; D013269:Stochastic Processes
keywords: Game theory; Moran process; Selection strength; Social behavior