title: Modeling multiallelic selection using a Moran model.
abstract: We present a Moran-model approach to modeling general multiallelic selection in a finite population and show how it may be used to develop theoretical models of biological systems of balancing selection such as plant gametophytic self-incompatibility loci. We propose new expressions for the stationary distribution of allele frequencies under selection and use them to show that the continuous-time Markov chain describing allele frequency change with exchangeable selection and Moran-model reproduction is reversible. We then use the reversibility property to derive the expected allele frequency spectrum in a finite population for several general models of multiallelic selection. Using simulations, we show that our approach is valid over a broader range of parameters than previous analyses of balancing selection based on diffusion approximations to the Wright-Fisher model of reproduction. Our results can be applied to any model of multiallelic selection in which fitness is solely a function of allele frequency.
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave., Room 4100, Cambridge, Massachusetts 02138, USA. muirhead@oeb.harvard.edu
authors.forename: Christina A
authors.initials: CA
authors.lastname: Muirhead
authors.forename: John
authors.initials: J
authors.lastname: Wakeley
mesh_terms: D005787:Gene Frequency; D005828:Genetics, Population; D008390:Markov Chains; D008957:Models, Genetic; D012098:Reproduction / Q000235:genetics; D012641:Selection, Genetic