A mode of selection in which individuals with extreme trait values have higher fitness compared to those with intermediate values
Although the popular view of natural selection evokes directional change – bigger, faster, smarter, more colorful – there are modes of selection that can lead to evolutionary change of a trait without directional shifts in its distribution. One example of this is disruptive selection, in which individuals with trait values close to the mean have lower fitness than those exhibiting more extreme values. Disruptive selection can lead to a bimodal distribution of trait values and therefore can result in an increase in the variance of a trait without a change in its mean.
Disruptive selection, also known as diversifying selection, refers to a selective regime in which extreme values have higher relative fitness than values closer to the mean. In a population genetic context in which a trait is influenced by a...