AP Success - AP Biology Conceptual Analysis: Evolution - Natural Selection

A group of finches inhabits an island with two types of seeds: small, soft seeds and large, hard seeds. The finches with small beaks can easily eat the small, soft seeds, while the finches with large beaks can crack open and eat the large, hard seeds. Over time, a drought causes the small, soft seeds to become scarce. Additionally, a new predator that targets finches with large beaks arrives on the island.

Describe how the concepts of natural selection and predator-prey interactions could affect these finches.

Given the change in seed availability and the introduction of a new predator, explain the likely effect on the finch population in terms of beak size and survival.

If the drought and the presence of the new predator persist for several more years, predict the likely outcome for the finch population.

Scientists claim that if the small, soft seeds become abundant again and the predator leaves the island, the population of finches with small beaks will not necessarily increase. Justify this claim.