Page:Popular Science Monthly Volume 15.djvu/267

Rh condition over the whole body (with trifling exceptions) in the average of all sexes, races, and ages. For this further and complete denudation I think we must agree with Mr. Darwin in invoking the aid of sexual selection, especially when we take into consideration the ornamental and regular character of the hairy adjuncts which man still retains.

In the first place, we have external reasons for believing that sexual selection has produced similar results elsewhere, acting upon a like basis of natural denudation. For among the mandrills and some other monkeys the naked callosities, originally produced, as is here suggested, by physical friction, have been utilized for the display of beautiful pigments; and Mr. Bartlett informed Mr. Darwin that as the animals reach maturity the naked surfaces grow larger in comparison with the size of the body. When we look at the great definiteness and strange coloring of these bare patches we can hardly doubt that they have been subjected to some such selective process.

But if man once began to lose the hair over the whole of his back, shoulders, and haunches, as well as more partially upon his sides, legs, and arms, he would soon present an intermediate half-hairy appearance which is certainly very ludicrous and shabby-looking. Why this middle stage should displease us, it might be rash to guess; yet one may remember that as a rule throughout the mammalia a partially hairless body would be associated with manginess, disease, and deformity. At any rate, it seems to be the fact that, when animals once begin losing their hair, they go on to lose it altogether. One may well believe that among our evolving semi-human ancestors those individuals which had most completely divested themselves of hair would be the most attractive to their mates; and these would also on the average be those which had most fully adopted the erect attitude with its accompanying alterations of habit. Thus natural selection would go hand in hand with sexual selection (as I believe it always does), those anthropoids which most nearly approached the yet unrealized standard of humanity being most likely to select one another as mates, and their offspring being most likely to survive in the struggle for life with their less anthropoid competitors. It does not seem probable, to me at least, that a naturally hairy species would entirely divest itself of its hair through sexual selection, especially as the first steps of such a process could hardly fail to render it a mongrel-looking and miserable creature; but it seems natural enough that, if the original impulse was given by a physical denudation, the influence of sexual selection would rapidly strengthen and complete the process. Indeed, if a hairy animal once began losing its hair, the only beauty which it could aim at would be that of a smooth and shiny naked black skin.

Woman is the sex most affected in mankind by sexual selection, as