Genetic drift: introduction
For the next couple of weeks we'll be exploring the consequences of life in finite populations. As I mention repeatedly in lecture, whenever I say the words "finite population" or "small population", you should immediately think "genetic drift". I'm sure you already have a general sense of what genetic drift is, the random change in allele frequencies over time that occurs simply because populations aren't infinite. What you probably know less well are the basic properties of drift: loss of diversity over time and accumulation of differences between populations. Once we have a basic understanding of genetic drift in an ideal population, which you should have by the end of the class period on Tuesday, we'll start exploring how to extend that understanding to more realistic situations.