Diversifying selection

Definition

Diversifying selection, also known as disruptive selection, is a type of natural selection that favors extreme phenotypes over intermediate ones. This process can lead to the development of two or more distinct forms within a population.

5 Must Know Facts For Your Next Test

1. Diversifying selection often occurs in environments where conditions are varied and multiple niches exist.
2. It can lead to an increase in genetic variance within a population.
3. This type of selection can result in speciation if the distinct forms become reproductively isolated.
4. A classic example of diversifying selection is seen in the beak sizes of Darwin's finches on the Galapagos Islands.
5. Diversifying selection can contribute to adaptive evolution by promoting traits that enhance survival and reproduction in different environmental contexts.

Review Questions

• What is diversifying selection and how does it differ from stabilizing and directional selection?
• How can diversifying selection lead to speciation?
• Give an example of an organism or scenario where diversifying selection has been observed.

Related terms

Stabilizing Selection: A type of natural selection that favors intermediate phenotypes, reducing variation.

Directional Selection:

A form of natural selection that favors one extreme phenotype over others, leading to a shift in the population's trait distribution.

Speciation: The formation of new and distinct species through evolutionary processes such as natural selection.