A study of inbreeding in some models of artificial selection

Abstract

An attempt is made to study the progress of inbreeding in a population by simple models of artificial selection. One or two top ranking individuals are selected based on the phenotypic value of a metric from theN progenies resulting from any particular mating (denoted as Model 1 and Model 2). The generation matrix method is employed to study the progress towards homozygosity. The probability that a selected individual is of a given genotype or that a selected pair consists of specified genotypes has been computed by numerical integration as well as by simulation, assuming the phenotypic distribution to be normal with the mean at the genotypic value and a given variance. It is observed that Model 1 promotes homozygosity more quickly than Model 2 as expected. Modifications due to dominance in the progress towards homozygosity are also discussed. The study throws some light on simulation studies in genetics.