The Descent of Man, and Selection in Relation to Sex is a book on evolutionary theory by English naturalist Charles Darwin, first published in 1871. It was Darwin's second book on evolutionary theory, following his 1859 work, On The Origin of Species. In The Descent of Man, Darwin applies evolutionary theory to human evolution, and details his theory of sexual selection. The book discusses many related issues, including evolutionary psychology, evolutionary ethics, differences between human races, differences between sexes, the dominant role of women in choosing mating partners, and the relevance of the evolutionary theory to society.