Charles Robert Darwin; FRS (12 February 1809 - 19 April 1882) was an English naturalist and geologist; best known for his contributions to evolutionary theory. He established that all species of life have descended over time from common ancestors; and in a joint publication with Alfred Russel Wallace introduced his scientific theory that this branching pattern of evolution resulted from a process that he called natural selection; in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding.

Darwin published his theory of evolution with compelling evidence in his 1859 book 'On the Origin of Species'; overcoming scientific rejection of earlier concepts of transmutation of species. By the 1870s the scientific community and much of the general public had accepted evolution as a fact. However; many favoured competing explanations and it was not until the emergence of the modern evolutionary synthesis from the 1930s to the 1950s that a broad consensus developed in which natural selection was the basic mechanism of evolution. In modified form; Darwin's scientific discovery is the unifying theory of the life sciences; explaining the diversity of life.