variance in the F 2 generation of divergently selected parents

Either by selective breeding for population divergence or by using natural population differences, T2 and advanced generation hybrids can be deveIoped vith high variances. We relate the size of the genetic lariance to the population divergence based on a forvard and backward mutation model at a locus with :wo alleles with additive gene action. The effects of Jopulation size and initial gene frequency are also explored. Larger parental population sizes increase the F2 genetic variance if the initial probability distribution .s uniform or U-shaped. However, population size has :he opposite effect if the initial distribution of gene ‘requencies is skewed such as it would be with newly Jrriving alleles. These alleles contribute to the genetic ;rariance sooner when the selection pressure is higher or when the effective population size is smaller.