TeXes Science Practice Test

In the given scenario, what type of selection is unlikely to occur as trees grow taller, impacting an herbivore's population?

1. Directional selection

2. Stabilizing selection

3. Disruptive selection

4. Sexual selection

The correct answer is: Stabilizing selection

As trees grow taller, stabilizing selection is unlikely to occur in the context of an herbivore's population. Stabilizing selection typically favors the average phenotype in a population while selecting against extreme variations. In the case of herbivores, if the trees become significantly taller, it may be the taller individuals of the herbivore population that are more successful at reaching food, leading to directional selection favoring those traits. In contrast, stabilizing selection would imply that the herbivores are maintaining an average height, which could hinder their ability to forage effectively in an environment where taller trees limit access to food sources for smaller individuals. Therefore, as the environment changes, stabilizing selection is not a fitting mechanism since it does not accommodate the shifts that taller trees bring to the herbivores' feeding behavior and survival.