I often see suggestions that random genetic drift drives speciation. I’m a bit skeptical of that idea. In any case, a discussion developed elsewhere, and Will Provine’s recent book on the topic was suggested as reading. I found the book interesting, though perhaps not decisive on the issues. So I am still at the same point of skepticism as where I started. But I at least have a better grasp of some of the issues.
I should add that I am not a biologist, though I have taken an interest in evolutionary biology.
What is random drift?
Let’s start by looking at the main issue. The proponents of random drift seem to be suggesting that
- there are near neutral mutations (neither benefiicial nor deleterious)
- by random chance, some of those neutral mutations take over the population (the new genes become fixed).
That is the sort of drift that Provine is discussing.