Models of long-term artificial selection in finite population with recurrent mutation

Abstract

The effects of mutation on mean and variance of response to selection for quantitative traits are investigated. The mutants are assumed to be unlinked, to be additive, and to have their effects symmetrically distributed about zero, with absolute values of effects having a gamma distribution. It is shown that the ratio [formula omited] of expected cumulative response to generation t from mutants, [formula omited], and expected response over one generation from one generation of mutants, [formula omited], is a function of t/N, where t is generations and N is effective population size. Similarly, [formula omited], is a function of t/N, where [formula omited] is the increment in genetic variance from one generation of mutants. The mean and standard deviation of response from mutations relative to that from initial variation in the population, [formula omited] in the first generation, are functions of [formula omited]. Evaluation of these formulae for a range of parameters quantifies the important role that population size can play in response to long-term selection. © 1986, Cambridge University Press. All rights reserved.