You may have noticed some similarities between drift and inbreeding. Specifically, both processes lead to a loss of heterozygosity and an increase in homozygosity. This analogy leads to a useful heuristic for helping us to understand the dynamics of genetic drift.
Remember our old friend
, the inbreeding coefficient? I'm going to
re-introduce you to it in the form of the probability that two alleles
chosen at random from a population are identical by descent. We're
going to study how
changes from one generation to the next as a
result of reproduction in a finite population.12
