The Savage
In The Descent of Man, and Selection in Relation to Sex Charles Darwin often draws on the imagery of the wild savages in their far away villages to describe some, in his words, "less evolved" forms of human society. He uses his experiences he shared with the indigenous population of Fireland (i.e. southern Argentina) as an indicator that humans all evolved from a common ancestor as he saw some rudimentary elements of so-called civilized behavior in them. However, the savage is described as a less evolved, less strong variety of the human race that will eventually be wiped out by the stronger populations.
Civilized Society
In contrast to the Savage, Charles Darwin uses the image of a perfect civilized society as the peak of evolution. He clearly ranks human populations on their evolutionary success and comes to the conclusion that the White European society is the most evolved and therefore strongest. While some of his contemporaries were inclined to use this argumentation for the euthanasia of weaker individuals or to justify slavery, Darwin argued that part of this evolutionary success is the moral code that evolved with us. He concluded that while our morals stop us to commit atrocities (they clearly did not), the evolutionary success of the peak race should lead to the disappearing of the less evolved ones when interbreeding happens more often.
Peacocks
The second part of this scientific work is the discussion of sexual selection, a theory devised to close the gap between nature's realities and the original theory of evolution. Within this argument Charles Darwin refers to the feathers of a male peacock to be the image that plagued him for years on end, as they seemed to make no evolutionary sense. The theory of sexual selection, however, manages to marry the huge cumbersome feathers with the evident evolutionary success of the species.
Human Skin
Another argument within the book is aimed at the general discussion at the time about the evolution of man himself. One side of society argued that all humans evolved from a common ancestor, while the other argued that human populations are so vastly different that they must have different origins. Being a strong supporter of the former argument, Charles Darwin uses the geographical gradual change of human skin color as the image to support this theory. He argues that if different populations came from different evolutionary lines, the skin color change would not be gradual but rapid.
