A balanced polymorphism (maintenance of multiple genotypes) exists through disruptive selection in seedcracker finches from Came
roon in which small- and large-billed birds specialize in cracking soft and hard seeds, respectively. If long-term climatic change resulted in all seeds becoming hard, which type of selection would then begin to operate on bill size in the finch population? A. directional selection
B. disruptive selection would continue to operate
C. stablilizing selection
D. no selection will operate on bill size following the climate change
The correct answer is option A. "directional selection".
Explanation:
Directional selection is a type of natural selection at which traits with extreme characteristics are selected over traits with medium characteristics. In this case, a long-term climatic change resulted in all seeds that are the fountain of food for finch becoming hard. This will result in a directional selection on bill size in the finch population, where large-billed birds will be selected over small and medium-billed birds.
