Genetic drift and natural selection

First, we'll review drift, mutation, and migration with a little help from this simulation:

• Allele frequency changes with genetic drift and mutation

Then we'll explore how natural selection interacts with drift.

You'll learn a couple of surprising things:

1. If the product of effective population size and the selective coefficient is less than 1, allele frequencies change roughly the same way they would as if there were no selection at all.
2. Most newly arisen mutations are quickly lost from populations, even if they are selectively advantageous.

Online notes