Select all of the characteristics that are considered to be evidence of natural selection that Darwin observed aboard the Beagle. Check All That Apply Collecting fossilized remains of extinct animals along the west coast of South America challenged Darwin's idea that the Earth was young. While studying tortoise and iguanas, Darwin noted that individuals can acquire characteristics that enable them to evolve over time. In regard to biogeography, Darwin discovered similar environments and animals with similar appearances in South America and Europe. Collecting fossilized remains of extinct animals along the west coast of South America, Darwin belleved that all species were created at the same time and did not change form. Darwin noted that unique island finch species are descendants from the mainland species that have developed adaptations to survive on the island's food source..