00:01
Lots of different forms of selection and a lot of different ways that we can see genetic drift.
00:06
However, there are some of the most common.
00:11
There's three of them.
00:12
There are, there is directional, there's stabilizing, and finally there's disruptive.
00:27
Now to explain all of these i'm going to use a graph and in that graph we're going to be looking at three different traits.
00:37
So we're going to say that the one in the middle is a medium height and then there's two extremes, one being short and one being tall.
00:48
So for a directional selection you have the normal selection which favors, you know, about twice as much of the middle or medium height as it does either extreme.
01:04
However in a directional selection you'll see that this graph is shifted to one side or the other.
01:11
So it might be shifted over towards tall and and so you have mostly the medium and tall population and very few short.
01:23
This can also go in the other direction where we have a lot of short and medium but very few tall...