title: Neutral aggregation in finite-length genotype space.
abstract: The advent of modern genome sequencing techniques allows for a more stringent test of the neutrality hypothesis of Darwinian evolution, where all individuals have the same fitness. Using the individual-based model of Wright and Fisher, we compute the amplitude of neutral aggregation in the genome space, i.e., the probability of finding two individuals at genetic (Hamming) distance k as a function of the genome size L, population size N, and mutation probability per base ν. In well-mixed populations, we show that for Nν<1/L, neutral aggregation is the dominant force and most individuals are found at short genetic distances from each other. For Nν>1, on the contrary, individuals are randomly dispersed in genome space. The results are extended to a geographically dispersed population, where the controlling parameter is shown to be a combination of mutation and migration probability. The theory we develop can be used to test the neutrality hypothesis in various ecological and evolutionary systems.
authors.affiliation: CNRS, LIPHY, F-38000 Grenoble, France and Université Grenoble Alpes, LIPHY, F-38000 Grenoble, France.
authors.forename: Bahram
authors.initials: B
authors.lastname: Houchmandzadeh
mesh_terms: D063147:Animal Distribution; D000818:Animals; D003198:Computer Simulation; D019143:Evolution, Molecular; D016678:Genome; D005838:Genotype; D008957:Models, Genetic; D009154:Mutation; D011336:Probability; D013269:Stochastic Processes