Moments for sum of an arbitrary function of gene frequency along a stochastic path of gene frequency change

A diffusion model is developed to compute any moment of the sum of an arbitrary function of the gene frequency along sample paths between any two specified frequencies. This is used to calculate the mean age of a mutant of frequency chi, including or excluding the possibility of its having been at value chi equals 1 during the process, and the total frequency of heterozygotes involving an allele since its origin.