Question

using the evidence provided, which of the following best justifies the researchers claim? a finch beak depth increased after the drought because the overall numbers of finches decreased, reducing competition for resources. b finch beak depth increased as a consequence of selective pressure after the drought because the remaining seeds were larger and harder. c finch beak depth increased after the drought due to intraspecific competition since finches with deeper beaks attract more mates. d finch beak depth increased after the drought due to increased predation since finches with deeper beaks can fight off predators more effectively.

Explanation:

In natural selection, environmental changes can lead to selective pressures. After a drought, if the remaining food - seeds are larger and harder, finches with deeper beaks are more likely to survive and reproduce as they can better access the food source. This leads to an increase in the average beak depth in the population over time. Option A is incorrect because a decrease in finch numbers reducing competition for resources doesn't directly explain the change in beak depth. Option C about mate - attraction is not supported by the data related to the drought. Option D about fighting off predators is also not indicated by the provided information on beak depth change after the drought.

Answer:

B. Finch beak depth increased as a consequence of selective pressure after the drought because the remaining seeds were larger and harder.