The human species

by A. de Quatrefages

According to Wallace, utility alone is able to account for the manner in which inferior animal forms could have produced apes, and afterwards a being having almost all the physical characters of man as he is now. This race lived in herds scattered throughout the hot regions of the ancient continent. It was not, however, wanting in true sociability; it possessed the perception of sensations, but was incapable of thought; moral sense and sympathetic feelings were unknown to it. It was still only a material outline of the human being, yet superior to the tailed man of Darwin, and to the pithecoid man of Haeckel.

Towards the earlier part of the tertiary period, adds Wallace, an unknown cause began to accelerate the development of the intelligence in this anthropoid being. It soon played a preponderating part in the existence of man. The perfection of this faculty became incomparably more useful than any other organic modification. Henceforward the powerful modifying agent of selection acted necessarily almost entirely in this direction. The physical characters already acquired remained almost unaltered, while the organs of the intelligence and the intelligence itself were perfected more and more in each generation. Animals unaffected by this unknown cause which separates us from them, continued to undergo morphological transmutations, so that since the Miocene epoch there has been a great change in the terrestrial fauna. With man only did the form remain the same. We ought not, therefore, to be surprised to find in the Quaternary epoch skulls like those of Denise and Engis, resembling those of men of the present age.

The superiority acquired by the intelligence has, moreover, removed our race for ever from the law of the action of morphological transmutations. His intellectual and moral faculties only are from this time subject to the power of selection, which will cause the disappearance of inferior races and their replacement by a new race, the lowest individual of which would be, in our time, a superior man.

After having read the pages, of which I have just made a summary, we cannot but be surprised to find Wallace declare that natural selection by itself is incapable of producing from an anthropoid animal, a man such as we find in the most savage nations known to us. He thus makes the human species an exception to the laws, which, according to him, rule all other living beings. There is a double interest in following Darwin’s rival in this new path.

Wallace begins by reminding us that natural selection rests entirely upon the principle of immediate utility, relative only to the conditions of the struggle maintained at the time by the individuals constituting the species. Darwin in all his works declares, on different occasions, this same principle, upon which rests, in fact, all his statements upon adaptation, the possibility of retrogressive transmutations, etc.

It results necessarily from this principle, that selection cannot produce variations in any way injurious to any being whatever. Darwin has often declared that a single well-attested case of this kind would destroy his whole theory.

But it is evident, adds Wallace, that selection is as incapable of producing a useless variation; it cannot then develop an organ in proportions which would go beyond its degree of present utility.

Now Wallace shews very clearly that in the savage there are organs whose development is out of all proportion with their present utility, and even faculties and physical characters which are either useless or injurious, at least to the individual. “But,” says he, “if it can be proved that these modifications, though dangerous or useless at the time of their first appearance, have become much more useful, and are now indispensable to the complete development of the intellectual and moral nature of man, we ought to believe in the existence of an intelligent action, foreseeing and providing for the future, just as we should do, when we see a breeder set to work to produce a definite improvement in any direction in any cultivated plant or domestic animal.”

The relative development of the body and the brain, the organ of intelligence, is one of the points upon which our author insists most strongly. The height of the orang, he says, is almost equal to that of man; the gorilla is much taller and bigger. Nevertheless, if we represent by ten the average volume of the brain in the anthropoid apes, this same volume will be represented by twenty-six in savages, and by thirty-two in civilised men. The English naturalist also makes the remark, that among savages, the Esquimaux, for instance, we find individuals the capacity of whose skull almost reaches the maximum which is given for the most highly developed nations.

Finally, Wallace, relying upon the experiments and calculations of Galton, admits distinctly that though the brain of savages is to that of civilised man in the proportion of five to six, the intellectual manifestations are, at the most, that of one to one thousand. The material development is, then, out of all proportion to the function. A brain, a little more voluminous than that of the gorilla, would, in the eyes of the eminent traveller, be perfectly sufficient for the inhabitants of the Andaman Islands, of Australia, Tasmania, and Tierra del Fuego.