ABSTRACT
As nearly two-thirds of “The Descent of Man” is taken up with the question of Sexual Selection and the courtships of insects, birds, mammals and man, it is necessary to make some passing reference to the subject. Sexual selection is less rigorous than natural selection. Generally the most vigorous males, those which are best fitted for their places in nature, will leave most progeny. When animals have their sexes separated, the males necessarily differ from the females in their organs of reproduction, and Darwin calls these organs the “primary sexual characteristics.” The secondary sexual characteristics according to Darwin, play a very large and important part in the improvement, modification and variation of the species. Darwin’s contention is that the latter have been developed by the influence of female choice of the most highly ornamental males. “Amongst birds,” says Darwin, “the contest is often of a more peaceful character.
