(1809–82), English natural historian and geologist, proponent of the theory of evolution by natural selection; full name Charles Robert Darwin. Darwin was the naturalist on HMS Beagle for her voyage around the southern hemisphere (1831–6), during which he collected the material which became the basis for his ideas on natural selection. His works On the Origin of Species (1859) and The Descent of Man (1871) had a fundamental effect on our concepts of nature and humanity's place within it.