Question

Describe each types of natural selection

Answer 1

I can think of three types of natural selection. I'm not sure why the question asks for four.

Here they are:
1) Stabilizing selection: this is when natural selection works against the two extremes of a trait to make the population more uniform. For example, stabilizing selection might work on the birth weight of human babies to keep them at an intermediate weight, because babies that are too big or too small have less chance of being born healthy.

2) Directional selection: this type of selection works to select the extreme of one trait. For example, in a population of plants, flowers with the brightest color might be selected for in order to attract the most pollinators.

3) Disruptive selection: this type of selection selects against the mean of the population. For example, if there are two types of seeds to eat for a population of birds, either of two different beak shapes (sharp or blunt) might be selected for, but a beak that's the average of the two shapes might not be particularly good at eating either seed, so it would be selected against.

Answer 2

Thanks