Darwin hypothesized that new species could appear gradually through small changes in an ancestral species. which observation that he made about finches most supports that hypothesis? a. the finches all ate the same materials as the mainland population. b. the finches were all relatively small compared to the mainland population. c. the finches all appeared to be related but differed from the mainland population. d. the finches were identical to the mainland population.

C. The finches all appeared to be related but different from the mainland population.

Darwin compared the finches of Galapagoes island and Mainland. He hypothesized the fact that one species might have migrated to the Galapagoes island from mainland and undergone with modifications in different ends from the ancestor species. He proposed that around 13 species of finches evolved from a single ancestor species. This process in which one species giving rise to multiple species which have different corresponding niches is called as adaptive radiation. These finches were adapted according to their different diets: seeds, flowers, insects and leaves. The ancestor finches were ground-dwelling and insect eating. The expense of speciation  in the Galapagoes island resulted in 14 species of finches which includes three species of ground-dwelling seed eaters, three others living on cactus and eating seeds, one living in trees and eating seeds, and 7 species of tree-dwelling insect-eaters. Therefore, the finches all appeared to be related but different from the mainland population.