Found on the Galapagos Islands are several species of finches, also known as Darwin's Finches. These finches co-exist on the islands, sharing the same habits and characteristics except for one; they all have differently shaped and sized beaks. The differences in their beaks might be the most important aspect of their survival. Notice that for about ten years, the populations of the two different finch species remained pretty stable largely because the two species had varied food sources. Then, in 1977, there was a huge drop in finches with small beaks and a great increase in large-beaked birds. How can you explain this?

Question

Responses
A The small-beaked finches became prey for larger animals.The small-beaked finches became prey for larger animals.
B The large-beaked birds preyed on the small-beaked birds.The large-beaked birds preyed on the small-beaked birds.
C The available food changed, the small beaked birds could not readily adapt and they began to die out.The available food changed, the small beaked birds could not readily adapt and they began to die out.
D Competition for food favored the large beaks; the small beaked birds had little or nothing to eat and they died off.

Answer 1

D Competition for food favored the large beaks; the small beaked birds had little or nothing to eat and they died off.