00:01
Unlike genetic drift, natural selection is, a, occurring at the species level, not population, b, a change of allele frequencies, c, only present in small populations, or d, influenced by the environment.
00:15
So these are pretty similar processes.
00:18
So genetic drift, we'll start with.
00:20
Genetic drift is where you get a change in allele frequencies, and you get it just because of random chance.
00:27
So because of random chance.
00:32
So even if you're looking at a population, there's a lot of chance involved.
00:37
They could die prematurely by bad luck.
00:41
They could be lucky, get a lot of food and have more offspring than expected based on their fitness.
00:45
There's a lot of probability involved in existing.
00:51
And genetic drift is a product of that.
00:56
Natural selection is very similar.
00:58
The only difference is it's not random.
01:02
So natural selection is a change in allele frequencies because some of the individuals are better suited to the environment than others...