Charles Darwin's On the Origin of Species changed the way we understand the beginnings of life on earth. Darwin's ideas challenged people to think differently, to question long-held beliefs, and to explore a new field of scientific discovery. As a young man, Darwin worked to join the priesthood, but his life took a turn toward science after he joined a government mission to South America and the Pacific. Darwin's work on the trip pushed him to come up with new ideas about life and nature, including his famous theory of evolution. Learn the story of one of the most important scientific thinkers of all time in Charles Darwin: British Naturalist.