Charles Robert Darwin was an English naturalist, geologist and botanist, best known for his contributions to the science of evolution. Darwin published his theory of evolution with compelling evidence in his 1859 book On the Origin of Species. His five-year voyage on HMS Beagle established him as an eminent geologist whose observations and theories supported Charles Lyell's conception of gradual geological change, and the publication of his journal of the voyage made him famous as a popular author. In 1871 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 (1872). His research on plants was published in a series of books, and in his final book, The Formation of Vegetable Mould, through the Actions of Worms (1881), he examined earthworms and their effect on soil