title: Estimation, variance and optimal sampling of gene diversity : I. Haploid locus.
abstract: An extension of Nei's analysis of diversity in a subdivided population is proposed for a haploid locus. The differentiation G STbecomes a natural extension of Wright's F STand generalizes Weir and Cockerham's parameter of co-ancestry by relaxing the assumption of identical correlation for all the alleles. Inter- and intrapopulation variances of the estimated diversities and differentiation are derived. Finally, the optimal sampling strategy for measuring G STwhen a fixed number of individuals can be analysed is considered. It is shown that, at a given locus, there is a unique sample size per population which yields the smallest variance of G ST,regardless of the number of populations studied. These theoretical developments are illustrated with an analysis of chloroplast DNA diversity in a forest tree. The results emphasize the necessity of sampling many populations, rather than many individuals per population, for an accurate measurement of the subdivision of gene diversity at a single locus.
authors.affiliation: Institut National de la Recherche Agronomique, Laboratoire de Biométrie, 78352, Jouy-en-Josas cedex, France.
authors.forename: O
authors.initials: O
authors.lastname: Pons
authors.forename: R J
authors.initials: RJ
authors.lastname: Petit