Human Origins

by S. Laing

L'HOMME AVANT L'HISTOIRE. (From Debierre.)

It will be seen at a glance that the Neanderthal skull, especially in the frontal part, which is the chief seat of intelligence, is nearer to the chimpanzee than to modern man. And all the other characters correspond to this inferiority of brain. The enormous superciliary ridges; the greater length of the fore-arm; the prognathous jaws, larger canine teeth, and smaller chin; the thicker bones and stronger muscular attachments; the rounder ribs; the flatter tibia, and many other characters described by palæontologists, all point in the same direction, and take us some considerable way towards the missing link which is to connect the human race with animal ancestors.

Still there are other considerations which must make us pause before asserting too positively that in following Quaternary man up to the Canstadt type, we are on the track of original man, and can say with confidence that by following it up still further we shall arrive at the earlier form from which man was differentiated. In the first place, Europe is the only part of the world where this Canstadt type has hitherto been found. We have abundant evidence from palæolithic stone implements that man existed pretty well over the whole earth in early Quaternary times, but have hitherto no evidence from human remains outside of Europe from which we can draw any inference as to the type of man by whom these implements were made. It is clear that in Europe the oldest races were dolichocephalic, but we have no certainty that this was the case in Asia, in so many parts of which round-headed races exclusively prevail, and have done so from the earliest times. Again, we have no evidence as to the origin of another of the most strongly marked types, that of the Negro, or of the Negrito, Negrillo, Bushmen, Australian, or other existing races who approach most nearly to the Simian type. The only evidence we have of the type of races who were certainly early Quaternary, and may very possibly go back to an older geological age than that of the men of Neanderthal and Spy, comes from the New World, from California, Brazil, and Buenos Ayres, and points to a type not so savage and Simian as that of Canstadt, but rather to that which characterizes all the different varieties of American man, though here also we find evidence of distinct dolichocephalic and brachycephalic races from the very earliest times. Another difficulty in the way of considering the Canstadt type as a real advance towards primitive man and the missing link, arises from the totally different and very superior type of Cro-Magnon being found so near it in time, as proved by the existence in both of the cave-bear, mammoth, and other extinct animals. We can hardly suppose the Cro-Magnon type to have sprung by slow evolution in the ordinary way of direct succession, from such a very different type as that of Canstadt during such a short interval of time as a small portion of one geological period. Again, it is very perplexing to find that the only Tertiary skulls and skeletons for which we possess really strong evidence, those of Castelnedolo, instead of showing, as might be expected, a still more rude and Simian aspect than that of Canstadt, show us the Canstadt type indeed, but in a milder and more human form.

All that can be said with certainty is, that as far as authentic evidence carries us back, the ancestral animal, or missing link, has not been discovered, but that man already existed from an enormous antiquity, extending certainly through the Quaternary into the Pliocene, and probably into the Miocene period, and that at the earliest date at which his remains have been found the race was already divided, as at present, into several sharply distinguished types.

This leaves the question of man's ultimate origin completely open to speculation, and enables both monogenists and polygenists to contend for their respective views with plausible arguments, and without fear of being refuted by facts. Polygeny, or plural origins, would at first sight seem to be the most plausible theory to account for the great diversities of human races actually existing, and which can be shown to have existed from such an immense antiquity. And this seems to have been the first guess of primitive nations, for most of them considered themselves as autochthonous, sprung from the soil, or created by their own native gods. But by degrees this theory gave place to that of monogeny, which has been for a long while almost universally accepted by the civilized world. The cause of this among Christians, Jews, and Mahometans has been the acceptance of the narratives in Genesis, first of Adam and secondly of Noah, as literally true accounts of events which actually occurred. This is an argument which has completely broken down, and no competent and dispassionate thinker any longer accepts the Hebrew Scriptures as a literal and conclusive authority, on facts of history and science which lie within the domain of human reason. The question, therefore, became once more an open one, but as the old orthodox argument for monogeny faded into oblivion, a new and more powerful one was furnished by the doctrine of Evolution as expounded by Darwin. The same argument applies to man as to the rest of the animal world, that if separate species imply separate creations, these supernatural creations must be multiplied to such an extent as to make them altogether incredible; as for instance 150 separate creations for the land shells alone of one of the group of Madeira islands; while on the other hand genera grade off into species, species into races, and races into varieties, by such insensible degrees, as to establish an irresistible inference that they have all been developed by evolution from common ancestors. No one, I suppose, seriously doubts that this is in the main the true theory of life, though there may still be some uncertainty as to the causes and mode of operation, and of the different steps and stages of this evolution. Monogeny therefore in this general sense of evolution from some primitive mammalian type, may be accepted as the present conclusion of science for man as it has come to be for the horse, dog, and so many other animals which are his constant companions. Their evolution can in many cases be traced up, through successive steps, to some more simple and generalized type in the Eocene; and it may be permitted to believe that if the whole geological record could be traced as far back as that of the horse, in the case of man and the other quadrumana, their pedigree would be as clearly made out. This, however, does not conclude the question, for it is quite permissible to contend that in the case of man, as in that of the horse, though the primary ancestral type in the Eocene may be one, the secondary types from which existing races are more immediately derived may be more than one, and may have been evolved in different localities. Thus in the case of the dog, it is almost certain that some of the existing races have been derived from wolves, and others from jackals and foxes; but this is quite consistent with the belief that all the canine genus have been evolved from the marsupial Carnivora of the Eocene, through the Arctocyon, who was a generalized type, half dog and half bear. In fact, we have the authority of Darwin himself, as quoted in the beginning of this chapter, for saying that this would be quite consistent with his view of the origin of species.

Now the controversy between monogenists and polygenists has turned mainly on these comparatively recent developments of secondary types. It has been fought to a great extent before the immense antiquity of the human race had been established, and it had become almost certain that its original starting-point must be sought at least as far back as in the Eocene period.

The main argument for monogeny has been that the different races of mankind are fertile among themselves. This is doubtless true to a great extent, and shows that these races have not diverged very far from their ancestral type. But the researches of Darwin and his successors have thrown a good deal of new light on the question of hybridity. Species can no longer be looked upon as separated from one another and from races by hard-and-fast lines, on one side of which is absolute sterility and on the other absolute fertility; but rather as blending into one another by insensible gradations from free intercrossing to sterility, according as the differences from the original type became more pronounced and more fixed by heredity.

To revert to the case of dogs, we find free interbreeding between races descended from different secondary ancestors, such as wolves, jackals, and foxes, though freer, I believe, and more permanent as the races are closer; but as the specific differences become more marked, the fertility does not abruptly cease, but rapidly diminishes. Thus Buffon's experiment shows that a hybrid cross between the dog and the wolf may be produced and perpetuated for at least three generations, and the leporine cross between the hare and rabbit is almost an established race. On the other hand, we see in the mule the last expiring trace of fertility in a cross between species which have diverged so far in different directions as the horse and the ass.