The human species

by A. de Quatrefages

At the present time there is a stag in Corsica, which from its form has been compared to the badger-hound: its antlers differ from those of European stags. Those who confine themselves to morphological characters, will assuredly consider this as a distinct species, and it has often been considered to be so. Now Buffon preserved a fawn of this pretended species, and placed it in his park; in four years it became both larger and finer than the French stags which were older and considered finer grown. Moreover, the formal evidence of Herodotus, Aristotle, Polybius and Pliny attest that in their time there were no stags either in Corsica or Africa. Is it not evident that the stag in question had been transported from the continent to the island; that under the new conditions the species had undergone temporary morphological modification, though it had lost none of its power of resuming its primitive characters, when placed in its primitive conditions of life?

Are we, then, to conclude that in time nature could have completed the action, and entirely separated the Corsican stag from its original stock? We may answer in the negative, if any weight is to be attached to experience and observation.

Species partially subject to the rule of man furnish a number of facts which enable us to compare the power of natural forces, when abandoned to their own action, with that of man in modifying a specific type. In all artificial races varieties are infinitely more numerous, more varied and more marked than wild races and varieties. Now the result of these transmutations of organisms has only consisted in the formation of races, never in the formation of a new species. Darwin himself accepts this conclusion implicitly in his magnificent work on pigeons; for when speaking of the races of pigeons he only says that the difference of form is such that if they had been found in a wild state, we should have been compelled to make at least three or four genera of them. The wild rock pigeons, the original stock of all our domestic pigeons, only differ, on the contrary, in shades of colour.

The result is always the same, whenever we can compare the work of nature with our own. When he has anything to do with any vegetable or animal species, man always changes its character, sometimes, after a lapse of some years, the change being much greater than that produced by nature since the species first came into existence. The effect of the conditions of life (milieu), of which we will speak presently, the struggle for existence and natural selection understood as I have just described it, the power which man possesses of directing natural forces and changing their resultant, easily explain this superiority of action.

Consequently, without leaving the domain of facts, and only judging from what we know, we can say that morphology itself justifies the conclusion that one species has never produced another by means of derivation. To admit the contrary is to call in the unknown, and to substitute a possibility for the results of experience.

Physiology justifies a still stronger assertion. Upon this ground also man is shown to be as powerful as nature, and for the same reasons. With our cultivated plants and domestic animals, it is not only the primitive form which has undergone change, but certain functions also. If we had only enlarged and deformed the wild carrot and the wild radish, it would not have become more eatable. To render it agreeable to our taste, the production of certain substances had to be reduced, and that of others enlarged, that is to say, nutrition and secretion had to be modified. If the functions in wild animal stocks had remained permanent, we should have had none of those races which are distinguished by a difference in the colour of the hair, in the production of milk, in aptitude for work, or in the production of meat. If instinct itself had not obeyed the action of man, we should not have had in the same kennel, pointers, grey-hounds, truffle dogs and terriers.

Nature produces nothing like this. To admit that similar results will one day follow from the action of natural forces is to appeal to the unknown, to possibility, and runs counter to all laws of analogy, and all the results furnished by experience and observation.

Man’s superiority over nature is quite as clearly shown in the group of phenomena, which relate to the question with which we are now dealing.

We have seen how rare are the cases of natural hybrids among plants themselves; we have also seen that no cases are known among mammalia. Now since man has begun to make experiments in this direction, he has increased the number of hybrids among plants, and among animals also. Moreover, he has succeeded in preserving for more than twenty generations, a hybrid which he has been able to protect from reversion and disordered variation. But we know the care that was necessary to insure the continuance of Ægilops speltæformis. If this plant had been left to itself, it would soon have disappeared.

The single exception which is known confirms therefore the law of sterility among species left to themselves. Now this law is in direct opposition to all the theories, which like Darwinism, tend to confuse species and race. This has been clearly understood by Huxley and has caused him to say, “I adopt the theory of Darwin under the reserve that proof should be given that physiological species can be produced by selective crossing.”