A scientist is studying beak length in a species of hummingbird. The scientist establishes a population of birds with beaks ranging from very small to very long and allows the population to breed for 10 years. At the end of the experiment, she finds that the majority of birds in the population have very long beaks. This is an example of _____ selection.
A)disruptive
B)stabilizing
C)directional
D)sexual

Question

Quizplus · Accepted Answer

Directional selection occurs when individuals with one extreme phenotype are favored over others, leading to a shift in the population towards that phenotype. In this scenario, birds with very long beaks were favored and as a result, the population shifted towards longer beaks. Disruptive selection favors extremes on both ends of the phenotype distribution and stabilizing selection favors the intermediate phenotype. Sexual selection is a type of selection that is driven by mate choice and is not applicable to this scenario.

A Scientist Is Studying Beak Length in a Species of Hummingbird