Charles Darwin's On the Origin of Species (publishe 1859) is a seminal work in scientific literature and arguably the pivotal work in evolutionary biology. The book's full title is On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, while for the 6th edition of 1872 the title was changed to The Origin of Species. It introduced the theory that populations evolve over the course of generations through a process of natural selection. Darwin's book was the culmination of evidence he had accumulated on the voyage of the Beagle in the 1830s and expanded through continuing investigations and experiments after his return.