Charles Darwin’s On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life is published on 24 November 1859. For the sixth edition of 1872, the short title will be changed to The Origin of Species.

Darwin’s book introduces the scientific theory that populations evolve over the course of generations through a process of natural selection. It presents evidence gathered from Darwin’s Beagle expedition in the 1830s and from his research, correspondence and experimentation to explain the diversity of living organisms and their adaptation to the environment. His theory proposes that the diversity of life arose by common descent through a branching pattern of evolution.

By the 1940s, Darwin’s concept of evolutionary adaptation through natural selection will have become central to modern evolutionary thinking and the unifying theory of the life sciences.  Despite the scientific consensus, religion-based political controversy over the teaching of evolution in schools, especially in the United States, will continue on into the 21st century.