Charles Darwin’s The Descent of Man exerted a vast influence over scientific and religious thinking in the 19th century, disturbing widely-held views on the origin of the human species, the age of the earth, and humans’s supposedly special role in the universe. Polarised debates tended to be pushed into the question as to whether ‘man was descended from monkeys’, and whether humans should be seen as ‘debased angels’ or ‘higher animals’. 

In the introduction to the book Darwin writes: 

The sole object of this work is to consider, firstly, whether man, like every other species, is descended from some pre-existing form; secondly, the manner of his development; and thirdly, the value of the differences between the so-called races of man.

Darwin’s book applied the theory of evolution through selection to the human species, through the process of sexual selection, and looked at the development of intellect and moral faculties with regard to how these influenced the choosing of sexual partners. Darwin was working at a time when the question of the relations between different races was developing through the field of anthropology, then a new science. Darwin’s study explored the nature of sexual attraction in birds, insects, fish and mammals, and within this framework looked at the cultures of sexual partnership within different human societies.