Further Observations on the Evolution of Additive Genetic Variation with Mutation

Two mutation models, LH by Lynch and Hill and CT by Cockerham and Tachida, utilized for a neutral quantitative character caused by genes with additive effects undergoing mutation and drift, were compared for the genetic variances within, σw2, and between, σb2, replicate small populations initiated from an almost fixed founder population. The two models give results that are very similar for σw2 and it is only after a very long time (too long for experimental verification) that they can be distinguished for σb2. The CT model also accommodates small replicate populations initiated from a very large equilibrium founder population. This provides information on the additive variance in the large equilibrium population. Reults from both types of founder populations provide information on the average mutation rate. Formulations for monoecy for the CT model are shown to be satisfactory for separate sexes with the substitution of the appropriate effective population size.