Charles Darwin was born in 1809 in England and studied medicine at the University of Edinburgh before switching to religion at the University of Cambridge. In 1831, he went on a five-year expedition to South America, Australia, and South Africa where he collected fossils and specimens. His famous book "On the Origin of Species" was published in 1859 and helped establish the theory that all species of life have evolved over time from common ancestors through the process of natural selection.