Man And His Ancestor: A Study In Evolution

by Charles Morris

There have very likely been many occasions where the changes in structure took place rapidly, in consequence of sudden variations in natural conditions. Such rapid changes in conditions necessarily exert a severe stress or strain on organisms, either destroying them or causing an equally rapid adaptation, physical or mental. In such instances it is likely that many species perish, the change demanded being too great; others escape by migration to better fitted localities; and others, more mobile or less affected by the change, survive through adaptive variations.

Of such periods of strain upon organic nature we know of only one in recent geological times, that known as the Glacial Age, the vast variation in climate which took place when the ice of the Far North flowed down in mighty billows over northern Europe and America, burying everything beneath its crushing weight, and bringing many forms of life to a sudden and untimely end. No doubt a considerable number of species of animals and plants perished before this frightful invasion. A notable instance among these was perhaps that of the American horse, which disappeared at about this period. Other species survived by a retreat to more tropical regions, to return after the invasion had spent its force. Still others may have survived by adapting themselves to the changed conditions, emerging as new species or well-marked varieties.

Among the beings which passed unscathed through this extraordinary change in climate was apparently man. And it seems safe to affirm that man's contest with the glacial conditions, whose force was exerted upon his mind instead of on his body, was one of the most potent influences in the evolution of the human race. Man entered the contest at a low level of mental development; he emerged from it at a comparatively high level.

No one to-day questions that man was an inhabitant of Europe during the Glacial Age. The proofs of this are too numerous and positive to be doubted. He may have inhabited America in the same period, though of this there still remains some doubt. Claims have been made of the discovery of evidences of man in Europe long before the glacial epoch, reaching as far back as the Pliocene and even the Miocene Age. But these claims have not been established beyond question, and the earliest generally acknowledged traces of man are confined to glacial Europe.

Yet we are forced to acknowledge that if man existed in Europe during the prevalence of the ice age, he, or his ancestor, must have been there before that period. It is absolutely certain that no animal accustomed to tropical conditions would have chosen this period of extreme cold to migrate from the warm tropics to the frozen north. The fact that man was in Europe during glacial times is the very strongest evidence that he reached there during the milder preceding period, when a genial and uniform climate is believed to have prevailed throughout southern and central Europe. If we could accept as fact the seeming very ancient evidences of man's handiwork, we would be obliged to consider him an inmate of Europe long ages before the glacial epoch.

If, as there is reason to believe, the man of Africa at that remote period was the ancestor of the forest-dwelling Pygmy of to-day, lower in mental level and more bestial in aspect than any of his descendants, yet much advanced in mind beyond the man-ape of earlier ages, then we may with some assurance accept this as the type of the primitive man of Europe. He could have reached there by the land bridges which are thought to have connected Europe and Africa at that time, one closing the straits at Gibraltar, the other extending south from Italy by way of Sicily. These were the routes by which the apes are supposed to have entered Europe, and by which man may well have followed in a later age. It is possible, indeed, that man reached the northern continent from another locality, the habitat of the Negrito race in southeastern Asia and the Malaysian islands. The fossil man-ape of Java, Pithecanthropus, is a strong argument that this was the region, or one of the regions, in which the development of man took place. However this be, we can be assured that primitive man was far more likely to widen his field of occupation through migration than any other animal, and may conjecture that he spread over Europe and Asia in the mild preglacial times, and perhaps even reached America, giving rise to the early man of that hemisphere.

The advent of man in Europe was not probably followed by any considerable intellectual development. The mild and equable climate which at that time seems to have prevailed, was not likely to make a stringent demand on his mental resources. Food was very likely abundant and easily obtained, animals of the chase being plentiful, and edible roots and fruits by no means lacking. Thus he could readily obtain the means of subsistence by aid of the arts and weapons employed by him in the tropical forests. It is not unlikely that some changes, both physical and mental, took place, but these were probably not great. There may have been some change in color and form, a first step toward the distinctions which separate the white from the black man, and a degree of mental adaptation to certain exigencies of the new situation; but in neither direction were the variations likely to be very decided.

Such, as we conceive it, was the man of early Europe, in great measure a counterpart of the forest nomad of the tropics of Africa and the East, the monarch of the animal kingdom, but not the lord of the earth. He may have made some progress in the contest with inanimate nature. Vegetable food in his new home was less abundant than in his old, and the instigation to agricultural pursuits was stronger. And though Europe was thickly wooded, it probably presented more open land than Africa. Both the incitement to agriculture and the facilities for its exercise were, in all probability, greater than in Africa, and man may have begun to cultivate the earth here at an earlier date than in his native realm. We are free at least to speculate that European man gained some slight knowledge of agriculture in the pre-glacial period, but this is doubtful, and the relics of early man yield no evidence in its favor. Mentally it is questionable if he was advanced beyond the level of the least developed negro tribes, and perhaps not beyond that of the forest pygmies.

But at length the shadow of a mighty coming change began to fall upon the fair face of Europe. Year by year the winters grew colder. The ice sheet, which was in time to bury half of Europe under its chilly mantle, had begun its slow movement toward the south. It advanced very slowly. Centuries elapsed during its deliberate march. Had it moved with rapidity, few animals could have survived its effects. Some of them found time for changes in structure to fit themselves to the new conditions. Others perished as the wintry chill increased. Constituted for tropical warmth, they were unable to endure severe cold. The apes and monkeys may have been among the early victims. To-day the apes of Gibraltar are the only ones existing in a wild state in Europe, and it is doubtful if they are of an original stock. There is good reason to believe that escape by migration southward was cut off by the sinking of the ancient land bridges, so that the animals north of the Mediterranean had no choice between adaptation and annihilation.

Among the animals thus taken prisoner by the glacial chill was European man. He could not escape, and was forced to remain, exposed to the alternatives of perishing from cold and hunger, or fitting himself to endure the new conditions which were coming upon his northern home, perhaps the most adverse to animal life that had ever been known. Man was about to be subjected to an extraordinary strain, which he could only meet by an extraordinary adaptation.