Question

Which of the following is the best explanation for why finches on one of the islands in the Galapagos have large beaks while finches on another island have small beaks?
a.
Over time, the finches on the island adapted as a result of competition for resources.
b.
Finches migrated until they found finches with similar beak sizes.
c.
Finches spontaneously changed their beak size in order to better access food supplies.
d.
Finches with large beaks are always better adapted to their environment. Finches with small beaks only survive on islands where there were never finches with larger beaks.

Answer 1

a.

This is best explained by natural selection: different islands have different food resources and competition, so over generations finches with beak sizes suited to the available food survived and reproduced more, leading to large beaks on one island and small beaks on another.