Darwin’s Finches Darwin observed an amazing diversity of creatures in Galapagos Islands. There he saw the small black birds, that amazed him the most, later called as Darwin finches. They represent one of the best examples of adaptive radiation.
He observed that there were many varieties of finches in the same island and all the varieties had evolved on the island itself from original seed-eating finches. He explained that after originating from a common ancestral seed-eating stock, the finches must have radiated to different geographical areas and undergone adaptive changes, especially in the type of beaks. Therefore, due to the alternation in beaks gradually, some became insectivorous and some vegetarian. Living in isolation for long, the new kinds of finches emerged that could function and survive in the new habitat.