As a young man in England, Charles Darwin had no idea what he wanted to do with his life. Then he was asked to go on a long ocean voyage. Boarding the ship Beagle in 1831, he spent nearly five years sailing around the world. He returned with one of the most important ideas in the history of science: the theory of evolution. It took him more than 20 years to publish a book about his theory. When his book, The Origin of Species, appeared in 1859, it aroused a great deal of controversy. It directly challenged many of the beliefs in the Bible. Darwin’s theory of evolution remains controversial today in the United States. Many Americans believe that what is in the Bible is true. There are numerous challenges to teaching evolution in schools.