| Method |
P.1673 right column bottom paragraph: "The human data on Mutation rates in higher eukaryotes based on specific loci are less reliable than the C. elegans, Drosophila and mouse data. A number of dominant-mutation rates have been inferred from the frequency of affected children of normal parents, and sometimes confirmed by equilibrium estimates for those dominants with severe effects. These values range from 10^-4 to 10^-6, with a rough average of 10^-5 (Vogel and Motulsky 1997). For genes of size 10^3 b, this corresponds to a rate of 10^-8 per b per generation. An estimate based on specific changes in the hemoglobin molecule gave 0.74×10^-8 per b per generation (Vogel and Motulsky 1997), but this is clearly an underestimate because other kinds of changes are not included. A third, quite independent estimate is based on rates of evolution of pseudogenes in human ancestry, which are likely to be identical to mutation rates (Kimura 1983a). This gives about 2×10^-8 per b per generation (Crow 1993, 1995). [Researchers] take 10^-8 as a representative value. However, because the overwhelming majority of human mutations occur in males (see below), the male rate must be about twice the average rate, or 2×10^-8. The number of cell divisions prior to sperm formation in a male of age 30 is about 400 (Drost and Lee 1995 Vogel and Motulsky 1997). Thus, µb≈2×10^-8/400=5 ×10^-11. For 8×10^7 genes (Bird 1995) of average size 10^3b, µeg≈0.004 and µegs≈1.6." |