(1809-82) the English naturalist who developed the theory of evolution by natural selection. As a young man he spent five years on a British ship, HMS Beagle, visiting coasts and islands in the southern part of the world. The different types of animals and plants that he found, especially on the Galapagos Islands in the Pacific, led him to believe that living things develop differently in different places over long periods of time. At that time, most western people believed that all things were created by God in seven days. Darwin returned to England in 1836 and spent the next 23 years collecting evidence to support his theory. When he published On the Origin of Species by Means of Natural Selection (1859) it caused much argument and anger because it seemed to disagree with the story of creation in the Bible. Most people now accept the main points of Darwin's theory, and many see it and the Bible as two ways of saying the same thing, but others, especially in the US, interpret the Bible account literally and believe that only creationism, also called creation science, should be taught in schools.