Solutions For An Introduction to Genetic Analysis Chapter 20 Problem 13P

During evolution, the different forces of breeding structure, mutation, migration and selection are entirely performing concurrently in populations. Any population of any species is limited in size; hence all populations must finally become homozygous and separated from one another as a result of inbreeding. Then evolution would stop. In environment, though new modification is always being present into populations by mutation and by particular migration between localities.

Therefore, the definite variation obtainable for natural selection is equilibrium among the introduction of new modification and its loss due to local breeding. A population will not differentiate from other populations by local breeding if

Where,

µ is the rate of mutation to new alleles per generations

N is population size.

For populations of intermediary and even quite large size, it is doubtful that Nµ > 1. For instance, if the population size is 100,000 then the mutation rate should go beyond 10^-5, which is a bit on the elevated part for prominent mutation rates, even though it is not an indefinite rate. In contrast, a migration rate of 10^-5 per generation is not excessively large.