The Descent of Man, and Selection in Relation to Sex

The Descent of Man, and Selection in Relation to Sex was a book on evolutionary theory by British naturalist Charles Darwin, first published in 1871. It was Darwin's second large book on evolutionary theory, following his 1859 work, The Origin of Species, and is concerned with outlining explicitly the application of Darwin's theory to human evolution, and outlining in detail the theory of sexual selection.

Part I: The evolution of man

Evolution of physical traits

In the introduction to Descent, Darwin lays out the purpose of his text:

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: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.

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Darwin's approach to arguing for the evolution of human beings is to outline how similar human beings are to other animals. He begins by using anatomical similarities, focusing on body structure, embryology, and "rudimentary organs" which are presumably useful in one of man's "pre-existing" forms. He then moves on to arguing for the similarity of mental characteristics.

Related Topics:
Anatomical - Embryology

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Evolution of mental traits

Based on the work of his cousin Galton, Darwin is able to assert that human character traits and mental characteristics are inherited the same as physical characteristics, and argues against the mind/body distinction for the purposes of evolutionary theory. From this Darwin then provides evidence for similar mental powers and characteristics in certain animals, focusing especially on apes, monkeys, and dogs for his analogies for love, cleverness, religion, kindness, and altruism. He concludes on this point that "Nevertheless the difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind." He additionally turns to the behavior of "savages" to show how many aspects of Victorian England's society can be seen in more primitive forms.

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In particular, Darwin argues that even moral and social instincts are evolved, comparing religion in man to fetishism in "savages" and his dog's inability to tell whether a wind-blown parasol was alive or not. Darwin also argues that all civilizations had risen out of barbarism, and that he did not think that barbarism is not a "fall from grace" as many commentators of his time had asserted.

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Natural selection and civilized society

In this section of the book, Darwin also turns to the questions of what would after his death be known as social Darwinism and eugenics. Darwin notes that, as had been discussed by Alfred Russel Wallace and Galton, natural selection seemed to no longer act upon civilized communities in the way it did upon other animals:

Related Topics:
Social Darwinism - Eugenics - Alfred Russel Wallace

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:"We civilised men, on the other hand, do our utmost to check the process of elimination; we build asylums for the imbecile, the maimed, and the sick; we institute poor-laws; and our medical men exert their utmost skill to save the life of every one to the last moment. There is reason to believe that vaccination has preserved thousands, who from a weak constitution would formerly have succumbed to small-pox. Thus the weak members of civilised societies propagate their kind. No one who has attended to the breeding of domestic animals will doubt that this must be highly injurious to the race of man. It is surprising how soon a want of care, or care wrongly directed, leads to the degeneration of a domestic race; but excepting in the case of man itself, hardly any one is so ignorant as to allow his worst animals to breed."

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But Darwin felt that these urges towards helping the "weak members" was part of our evolved instinct of sympathy, and concluded that "nor could we check our sympathy, even at the urging of hard reason, without deterioration in the noblest part of our nature." As such, '"we must therefore bear the undoubtedly bad effects of the weak surviving and propagating their kind." Darwin was sympathetic to the views of the Social Darwinists and the eugenicists, but he did not believe that action should be taken. He did feel, though, that the "savage races" of man would, like it or not, be subverted by the "civilised races" at some point in the near future: "At some future period, not very distant as measured by centuries, the civilised races of man will almost certainly exterminate, and replace, the savage races throughout the world." He did show a certain disdain for "savages," professing that he felt more akin to certain altruistic tendencies in monkeys than he did to "a savage who delights to torture his enemies." However, Darwin is not advocating genocide, but clinically predicting, by analogy to the ways in which "more fit" varieties within a species would displace other varieties, the likelihood that indigenous peoples will eventually die out from their contact with "civilization", or become absorbed into it completely.

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His political opinions (and Galton's as well) were strongly inclined against the coercive, authoritarian forms of eugenics which later became so prominent in the twentieth century. It is worth noting that even Galton's ideas about eugenics were not the compulsory sterilization or genocidal programs of Nazi Germany, but he instead hoped that by encouraging more thought in hereditary reproduction, human mores could change in a way which would compel people to choose better mates.

Related Topics:
Compulsory sterilization - Nazi Germany

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For each tendency of society to produce negative selections, Darwin also saw the possibility of society to itself check these problems, but also noted that with his theory "progress is no invariable rule." Towards the end of Descent of Man, Darwin said that he believed that man would "sink into indolence" if severe struggle was not continuous, and thought that "there should be open competition for all men; and the most able should not be prevented by laws or customs from succeeding best and rearing the largest number of offspring," but also noted that he thought that the moral qualities of man were advanced much more by habit, reason, learning, and religion than by natural selection. The question would plague him until the end of his life, and he never concluded fully one way or the other about it.

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The race debate

Darwin lastly applied his theory to one of the more controversial scientific questions of his day: whether the different races of human beings were of the same species or not:

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:The question whether mankind consists of one or several species has of late years been much discussed by anthropologists, who are divided into the two schools of monogenists and polygenists. Those who do not admit the principle of evolution, must look at species as separate creations, or as in some manner as distinct entities; and they must decide what forms of man they will consider as species by the analogy of the method commonly pursued in ranking other organic beings as species.

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Darwin reasoned that most of the visual differences between human races were superficial—issues of skin color and hair type—and that most of the mental differences were merely cases of "civilization" or a lack of it. It was important to Darwin to argue that all races were of the same species—he had spent much of the preceding book tracing humans back to the paleolithic age, and now he had to bring them back to the present time again. If the "savages" like those he met while on his Beagle voyage were not of the same species as civilized Englishmen, he would not be able to draw the complete continuum he felt necessary. Darwin concluded that the visual differences between races were not adaptive to any significant degree, and were more likely simply caused by sexual selection—different standards of beauty and mating amongst different people—and that all of humankind was one single species.

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He concludes that "when the principle of evolution is generally accepted, as it surely will be before long, the dispute between the monogenists and the polygenists will die a silent and unobserved death." In one sense he was correct: few people, outside of the anthropologists of the American South, would maintain that different races were actually distinct species of animals for very much longer—among other things, the mounting evidence of their ability to interbreed and have fertile young could not be ignored. However, many found it easy to take a similar view to the old polygenism: that the races were indeed one species, but had diverged so long ago that significant differences between the races still existed. The evolutionary point fell out of debate, but the social point has continued (both inside and outside scientific circles) to the present day.

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Darwin's belief in male superiority

In Descent of man Darwin wrote: "The chief distinction in the intellectual powers of the two sexes is shewn by man's attaining to a higher eminence, in whatever he takes up, than can woman - whether requiring deep thought, reason, or imagination, or merely the use of the senses and hands"(Chapter 19, 1871 edition Darwin, Descent of Man - Chapter 19 - Secondary Sexual Characters of Man Darwin's errant thoughts on male superiority in respect to "whatever he takes up" probably reflected the views of many living at the same time in Victorian England.

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