Darwin observed many finch species on the Galapagos Islands. To explain these observations, he proposed that each species evolved from the same common ancestor, which was a finch species that migrated to the islands from the mainland. What additional evidence did Darwin use to support his explanation?
A. The finch populations were very numerous, and different species often bred with one another.
B. The finch species lived in different habitats on different islands, which isolated them from one another.
C. The finch species were distributed evenly among all of the islands, but did not interbreed.
D. The beaks of the finches were identical, allowing them to eat the same foods on any of the islands.