PCB 4674C Lecture Notes - Lecture 31: Allele Frequency, Mutation Rate, Zygote
Document Summary
Assume that an allele a mutates to a at some rate. Assume further that there is no back mutation (this maximizes the possible effect): then, if f(a)t+1 = (1- ) f(a)t f(a)t = (1- )t f(a)0. How many generations would it take to reduce: f(a) from 0. 9 to 0. 1. Solve the above equation for t: if = 10-6, a typical mutation rate, t = 2. 2 x 106 generations or 2 million, two hundred thousand generations. So with typical mutation rates, mutation will have little effect on allele frequencies. This does not mean that mutation is not important to generating new variation in populations, just that the mutation rate does not result in rapid changes in allele frequency. V natural selection (1) selection occurs because individuals of different genotypes consistently differ in survival and/or ability to produce offspring (fecundity). Consider selection on a continuously varying trait.
