Different finch species have beaks of different shapes and sizes. What do these beak differences tell us?

Differences in beak shapes tell us that all the finches eat the same type of food. Different finch beak shapes are evidence that all Galápagos finches shared a common ancestor a long time ago. Different finch beak shapes are evidence that over time, finch species adapted to different food sources on the islands.

Explanation:

the correct answer is:

a population changes in response to a change in the environment.