Charles Robert Darwin (12 February 1809 – 19 April 1882) was an English naturalist.[I] After becoming eminent among scientists for his field work and inquiries into geology, he proposed and provided scientific evidence that all species of life have evolved over time from one or a few common ancestors through the process of natural selection. The fact that evolution occurs became accepted by the scientific community and the general public in his lifetime, while his theory of natural selection came to be widely seen as the primary explanation of the process of evolution in the 1930s, and now forms the basis of modern evolutionary theory. In modified form, Darwin’s scientific discovery remains the foundation of biology, as it provides a unifying logical explanation for the diversity of life.
Darwin developed his interest in natural history while studying first medicine at Edinburgh University, then theology at Cambridge. His five-year voyage on the Beagle established him as a geologist whose observations and theories supported Charles Lyell’s uniformitarian ideas, and publication of his journal of the voyage made him famous as a popular author. Puzzled by the geographical distribution of wildlife and fossils he collected on the voyage, Darwin investigated the transmutation of species and conceived his theory of natural selection in 1838. Although he discussed his ideas with several naturalists, his other work had priority and he needed time for extensive research to meet anticipated objections. He was writing up his theory in 1858 when Alfred Russel Wallace sent him an essay which described a similar theory, prompting immediate joint publication of both of their theories.
His 1859 book On the Origin of Species established evolution by common descent as the dominant scientific explanation of diversification in nature. He examined human evolution and sexual selection in The Descent of Man, and Selection in Relation to Sex, followed by The Expression of the Emotions in Man and Animals. His research on plants was published in a series of books, and in his final book, he examined earthworms and their effect on soil.