Question

natural selection does not cause a change in the average value of a trait, but it leads to an increase in genetic variation in population. which of the following has occurred?
disruptive selection
directional selection
stabilizing selection
directional selection and stabilizing selection
stabilizing selection and disruptive selection

Explanation:

• Disruptive selection: Favors extreme phenotypes over intermediate ones. It does not change the average value of a trait but increases genetic variation as extreme forms become more common.
• Directional selection: Shifts the population towards one extreme phenotype, thus changing the average value of the trait.
• Stabilizing selection: Favors intermediate phenotypes, reducing genetic variation and keeping the average value of the trait relatively stable.

Since the problem states that there is no change in the average value of the trait but an increase in genetic variation, only disruptive selection fits this description.

Answer:

disruptive selection