Page:Evolution of Life (Henry Cadwalader Chapman, 1873).djvu/203

Rh to place itself in the evening at the entrance of its burrow, and stridulate until a female approaches, when the louder notes are succeeded by a more subdued tone, whilst the successful musician caresses with his antenna; the mate he has won." Ornaments of the male animal, like the cock's comb, the peacock's tail, the gorgeous plumage of the paradise bird, the brilliant color of the male butterfly, are made use of, like the weapons and musical tones just mentioned, in obtaining the female. The old Spartan principle of killing the deformed and sickly, which resulted in the production of a magnificent race of men, is the action of Sexual Selection applied to man. Necessarily the offspring will exhibit marked improvement in beauty of form, development of talent, and powers of defense, if the fathers are always selected from those who approach nearest the standard of excellence.

Having illustrated now, we hope sufficiently well, the selection brought about by man and nature, let us see how they differ and in what they agree. Man selects knowingly, with an object; making use of variations, he modifies for his own advantage. Nature eliminates blindly, without an object, the organisms surviving being better fitted for existence through some advantage. Thus the Massachusetts farmer knowingly made use of the variation of a long body and short bandy legs, exhibited by one of his rams, to produce a particular race of sheep. But suppose the conditions of existence had been such that the short-legged sheep had some advantage over the long-legged ones in the struggle for existence, the favored ones would have survived, and nature blindly would have done in the long run what the farmer did in a few generations. A similar case would be that of a farmer who, having black and white pigs, wanted black pigs only. To attain this object he would knowingly separate the pigs, and breed from the black pigs alone. But if