Question

The extremes of dry and wet weather of the Galapagos Islands cause the food supply to constantly change.

During dry years, the food is mainly large, hard seeds, and finches with large beaks are found in greater
numbers.
Which statement best explains this observation?
(1) Dry environments cause mutations in finches.
(2) Finches grow larger when they have more water.
(3) Small finches become smaller during dry seasons.
(4) Large beak size is an adaptation to dry conditions.

Answer 1

Since during the dry years, the food are mainly large so finches with large beaks are selected for while small beaked finches are selected against. Large beaked finches adapted to this dry condition to survive and reproduce. Therefore, fourth statement is correct.