The Distribution of Gene Frequencies Under Irreversible Mutation

Abstract

This paper de-velops equations which must hold under equilibrium of form in the distribution of frequencies of a gene subject to irreversible mutation. The formula of the distribution itself is derived for various cases, including the case in which mutation is reversible or, if irreversible, is opposed by strong selection, that in which there is no selection but opposed mutation rates of any magnitudes, and that in which the population is so small that mutation pressures have no effect on the form of distribution. The evolutionary significance of the results is discussed briefly.