Charles Darwin's On the Origin of Species (published 24 November 1859) is a seminal work in scientific literature and a landmark 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. In 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 contained a wealth of evidence that the diversity of life arose through a branching pattern of evolution and common descent – evidence which he had accumulated on the voyage of the Beagle in the 1830s and expanded through research, correspondence, and experiments after his return.
The book is readable even for the non-specialist and attracted widespread interest on publication. The book was controversial because it contradicted creation myths that underlay the then current theories of biology, and it generated much discussion on scientific, philosophical, and religious grounds. The scientific theory of evolution has itself continued to evolve since Darwin's contributions, but natural selection remains the most widely accepted scientific model of speciation. Despite the overwhelming scientific consensus, political and religious challenges to the theory of evolution continue to this day in some countries.