Chapter 21, Problem 22P

Three basic predictions underlie genetic drift in populations: (1) As long as the population size is finite, some level of genetic drift will occur; thus, without new mutations, all variation will drift either to fixation or to loss. (2) Drift happens faster in small populations than in large populations. (3) The probability that an allele is fixed (goes to a frequency of 1.0) is equal to its initial frequency (p) in the population, while its probability of loss from the population due to drift is equal to 1 − p. Given these three predictions:

a.	What is the allele frequency of a new autosomal mutation immediately after it occurs in a diploid population of size N = 100,000?
b.	What is the allele frequency of a new autosomal mutation immediately after it occurs in a diploid population of size N = 10?
c.	In which population does the new mutation have a higher probability of going to fixation by chance with genetic drift?