Question

By studying medium ground finch populations over the course of several decades, the Grants and their colleagues have demonstrated that, during drought years, natural selection favors birds with _______ beaks; during wet years, natural selection favors birds with ________ beaks.

A. deep/deep
B. deep/shallow
C. shallow/deep
D. shallow/shallow

Answer 1

During drought years, natural selection favors birds with deep beaks; during wet years, natural selection favors birds with shallow beaks.

Step-by-step explanation:

The answer is B. deep/shallow. The Grants and their colleagues studied medium ground finch populations on the Galápagos and found that during drought years, when small seeds with thin shells were rare, natural selection favored birds with deep beaks that could crack open and eat large, hard seeds. However, during wet years when there was an abundance of small, soft seeds, natural selection favored birds with shallow beaks that could efficiently eat these seeds.