Data on survival of juvenile black-bellied seedcrackers as a function of beak size is shown in the accompanying figure.Given the relative survival rates of juvenile birds in terms of both the lower mandible width and length,this is a clear example of ________.
A) directional selection
B) stabilizing selection
C) disruptive selection
D) selection gradient

Question

Data on survival of juvenile black-bellied seedcrackers as a function of beak size is shown in the accompanying figure.Given the relative survival rates of juvenile birds in terms of both the lower mandible width and length,this is a clear example of ________. 
A) directional selection 
B) stabilizing selection 
C) disruptive selection 
D) selection gradient

Quizplus · Accepted Answer

The data shows that birds with either very small or very large beak sizes have lower survival rates compared to birds with intermediate beak sizes. This suggests that disruptive selection is at play, as extreme phenotypes are being selected against in favor of the intermediate phenotype.

Data on Survival of Juvenile Black-Bellied Seedcrackers as a Function