The British surveying ship the HMS Beagle makes the first stop of its expedition, arriving on Santiago Island in the Cabo Verde archipelago. On board is Charles Darwin, age 22. Darwin spends 21 days on the island doing geological work. Encountering a band of limestone exposed on a cliff and containing marine fossils that are now high above sea level, he sees evidence that the Earth formed through a geological evolutionary process, contrary to the current scientific belief that the planet formed through a series of cataclysms. On his return visit in 1836, Darwin will begin applying the the theory of evolutionary development to animal species.