diffusion method

Ohta T & Kimura M 1971 Genetic load due to mutations with very small effects. Jpn J Genet 46:393-401.

• Φ(p, x) = ν_m∫₀^∞φ(p, x; t)dt
• Φ(p, x) gives the steady flux distribution
• Φ(p, x)dt represents the expected number of sites in which the frequency of the mutant form is in the range (x, x + dx), restricting our consideration only to segregating sites
• the above treatment with respect to Φ(p, x) is an extension of the work of Wright (1938, 1942, 1945) on the distribution of gene frequencies under irreversible mutations

• the mutational load is a special type of substitutional load in which the initial frequency of the advantageous allele is very high

• F(p) = I_f(p)/ν_m
• F(p) with p = 1/2N represents the genetic load of an equilibrium population in which one new mutant is supplied each generation
• F(p) also represents the average total load created by one mutant from the time of occurrence until its fixation or loss