The Descent of Man, and Selection in Relation to Sex

The Descent of Man, and Selection in Relation to Sex is a book by English naturalist Charles Darwin, first published in 1871, which applies evolutionary theory to human evolution, and details his theory of sexual selection, a form of biological adaptation distinct from, yet interconnected with, natural selection. Darwin used the word "descent" to mean lineal descendant of ancestors.

Source: Wikipedia — The Descent of Man, and Selection in Relation to Sex (CC BY-SA 4.0)