A model for analysis of population structure

Abstract

Arguments are presented for the appropriateness of a multinomial Dirichlet distribution for prescribing single locus genotypic frequencies in a subdivided population. This distribution is defined as a function of allele frequency, the average (over the entire population) inbreeding coefficient and the correlation between genotypes within a subdivision. Alternative parameterizations and their genetic interpretations are given. It was then shown, how information from a sample drawn from this subdivided population, in the absence of pedigrees, can be combined with the multinomial Dirichlet model to form a likelihood function. This likelihood function is then used as the basis for estimation and testing hypotheses concerning the genetic parameters of the model. Comparisons of this approach to the alternative procedure of Cockerham are made using data obtained from Tecumseh, Michigan and Monte Carlo simulations. Finally, implications of these results to statistical interference and to mutation rates are presented.