title: Allelic diversity and its implications for the rate of adaptation.
abstract: Genetic variation is usually estimated empirically from statistics based on population gene frequencies, but alternative statistics based on allelic diversity (number of allelic types) can provide complementary information. There is a lack of knowledge, however, on the evolutionary implications attached to allelic-diversity measures, particularly in structured populations. In this article we simulated multiple scenarios of single and structured populations in which a quantitative trait subject to stabilizing selection is adapted to different fitness optima. By forcing a global change in the optima we evaluated which diversity variables are more strongly correlated with both short- and long-term adaptation to the new optima. We found that quantitative genetic variance components for the trait and gene-frequency-diversity measures are generally more strongly correlated with short-term response to selection, whereas allelic-diversity measures are more correlated with long-term and total response to selection. Thus, allelic-diversity variables are better predictors of long-term adaptation than gene-frequency variables. This observation is also extended to unlinked neutral markers as a result of the information they convey on the demographic population history. Diffusion approximations for the allelic-diversity measures in a finite island model under the infinite-allele neutral mutation model are also provided.
authors.affiliation: Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, 36310 Vigo, Spain.
authors.forename: Armando
authors.initials: A
authors.lastname: Caballero
authors.forename: Aurora
authors.initials: A
authors.lastname: García-Dorado
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D019143:Evolution, Molecular; D005787:Gene Frequency; D008957:Models, Genetic; D009154:Mutation; D012641:Selection, Genetic; D013997:Time Factors
keywords: diffusion approximations; gene diversity; heterozygosity; number of alleles; response to selection; selection limits