Genetical Research

Research Article

The genetic variability of polygenic characters under optimizing selection, mutation and drift

M. G. Bulmera1

a1 Department of Biomathematics, University of Oxford


The effect of optimizing selection, mutation and drift on a metric character determined by a large number of loci with equal effects without dominance was investigated theoretically. Conditions for a stable equilibrium under selection and mutation, in the absence of drift, have been obtained, and hence the amount of genetic variability which can be maintained by mutation has been determined. An approximate expression for the average amount of genetic variability to be expected in the presence of drift in a population of finite size has also been obtained and evaluated.

(Received May 10 1971)