Man And His Ancestor: A Study In Evolution

by Charles Morris

The changes by which he met these new conditions were in a very small degree physical; they were almost wholly mental. In all animals of the higher orders, adaptive variations are apt to be in a measure of this character, the body being relieved from the need of structural change through some new activity of the mind. In man this was undoubtedly the case in great, probably in very great, measure. There may have been an increase in size and strength, some variations in color, in the breathing organs, in power of resistance of the cuticle to cold, etc., but the principal physical change was in a growth of the brain and expansion of the cranium, giving rise to a less bestial physiognomy and an advanced mental power.

One physical change that would seem necessary to enable an animal to endure severe cold, the development of a thick protective covering of fur or hair, did not take place in man. The change was more likely in the other direction, since the hairy cover which is possessed by many of the forest folk has disappeared. This loss of hair by man has been referred by Darwin to sexual selection, that powerful influence to which animals seem to owe so many physical structures of no apparent use, and some of them seemingly disadvantageous. In the case of man in the circumstances now under consideration, exposed without natural covering to the growing chill of the advancing ice sheet, the influence of sexual selection would certainly have found a strong counteracting force in natural selection, had not some other means of escaping the influence of the cold been found.

As it was, the difficulty was undoubtedly overcame in great measure by the adoption of artificial clothing. The mind came to the aid of the body. The man who could chip a stone into the shape of an axe or spear head, was sufficiently advanced mentally to conceive the idea of covering his body with leaves fastened together in some way, with other vegetable fabrics, or with the skins of slain animals. Protection from the cold was also sought in caverns and rock shelters, and for a very long period man remained a cave-dweller. There is hardly a cavern in western Europe in which he has not left some trace of his residence. Where caves were not available, rude artificial shelters were probably built. Even the orang builds a shelter of this kind, and we can readily conceive of man at a very early period making himself a shelter of leaves and boughs, from which, as the cold increased, he might easily evolve a hut composed of a wooden framework covered with skins such as he used for clothing.

When and where the most important of discoveries, that of fire, was made, it is impossible to say. Fire arising from natural causes, such as conflagrations started by lightning, no doubt early taught man the advantage of this agency as a protection from cold, but the artificial production of fire was a process too intricate to be arrived at by undeveloped man except as a result of accident. It has never been achieved, as we have seen, by the Andaman Mincopies. The rudiments of the fire-making art were possessed by primitive man. In chipping flints into arrow or lance heads sparks must frequently have been struck from the hard stone, and at times these may have fallen upon and kindled inflammable material. The rubbing requisite in shaping and polishing war clubs may have yielded a heat occasionally causing fire. In boring the holes necessary to make the needles found among primitive implements, a process resembling that of the fire-drill must have been employed. In short, it is not difficult to conceive of more than one way in which the fire-making art could have been gained by accident, though it may have been late in coming, since some, perhaps all, of the arts described were not attained until the Glacial Age. Once possessed, this important art would scarcely have been suffered to disappear. With its aid man could defy the effects of the glacial chill, so far as its direct action upon his body was concerned; and with it he also gained a new and efficient means of defence against carnivorous animals, which have ever since feared fire more than weapons.

The discovery of methods of artificial fire-making was perhaps preceded by a utilization of the flames caused by lightning and other natural causes, the fire being conveyed by torches from hearth to hearth and kept alive with sedulous care. Even after artificial methods of fire-making were invented, our savage ancestors were exceedingly careful to keep their fires alive, as the Mincopies are to-day, and this heedful attention left its traces until very recent times. So important was the apparatus for kindling a flame deemed that in India the fire-twirl was made a god and became one of the chief deities of that polytheistic land. In many other places, especially in Persia, the element of flame was raised to the dignity of a deity and worshipped among the higher gods. Among the semi-civilized Americans the peril of the loss of fire gave rise to a serious religious ceremony. At certain set intervals all the fires within the limits of a tribe or nation were extinguished, and a period of gloom, despondency, and dread of the malignant powers succeeded. Then the "new fire" was kindled on the temple altar, and the flame was conveyed by swift messengers from hearth to hearth throughout the land. This done, the period of gloom was followed by one of general joy and festivity. The malignant deities were banished; the gods of light and warmth were dominant again; happiness and security had returned to man.

The beginning of the use of clothing, of artificial shelter, and of fire formed one of the most vital periods in the history of human evolution. Coincident with them was the production of a much greater variety of implements than had been previously possessed, and many of these much superior to the older and ruder forms. The struggle with the glacial cold had roused man's mind out of its old sluggishness, and brought it actively into operation in devising means of counteracting the perils of his situation and fitting him to the new conditions of existence.

Among the important steps of progress was very likely a considerable advance in the use of language, enabling the men of that period more readily to consult with and advise one another, to give adequate warning of danger, to aid in the chase or in industrial pursuits, to educate the young and impart new ideas or teach new discoveries to the old. The mental powers of the best-trained individuals then as now served the whole community, and nothing of value that was once gained was likely to be lost. Discovery and invention at that early period probably went on with interminable slowness as compared with the progress in later ages, yet even then new ideas, one by one, came into men's minds, and step by step the methods of life were improved.

One important effect of the glacial chill needs to be adverted to. The severity of the weather was not the only thing to be provided against. The discovery of fire and the invention of clothing and habitation were not enough to insure man's preservation. For the severe cold must have greatly changed the conditions of the food supply, and the man of the period found it a difficult matter to obtain the first necessaries of life. The easy-going man of the earlier age, living amid an abundance of fruits and vegetables and surrounded by numbers of game animals, or dwelling beside streams which were filled with easily taken fish, probably found the question of subsistence one of minor importance. The coming on of the Glacial Age made this question one of major importance. The supply of fruits and vegetable substances was greatly decreased by the biting chill, and the number of food animals was correspondingly reduced; while through much of the year the effects of frost drove the fish from the streams, and cut off effectually this source of food. Man was brought into a situation in which only the most active exertion of his powers of thought could preserve him from annihilation.

He now found the exercise of the art of hunting more difficult than ever before, one that needed a new development of courage, cunning, alertness, and endurance, the scarcity of animals obliging him to make long journeys and attack the strongest creatures. Whether or not he possessed the poisoned arrow, which the Pygmies now find so effective, cannot be said, but in all probability he was forced to invent new and more destructive weapons, a necessity that gave fresh exercise to his powers of invention. So far as our actual knowledge goes, the art of chipping stones into weapons and implements was not possessed before this period, and it may have been a result of the severe exigencies of the situation and the mental stimulation thence resulting. This art is not possessed by any of the Pygmies, the nearest approach to it being the splitting of stone by fire and using the splinters as weapons. Very likely preglacial man was similarly destitute of this art.

Under the severe strain of the glacial conditions the weak and incapable doubtless succumbed to the cold and deficiency of food; the strong and capable survived, gained superior powers, devised new weapons and implements, and became adapted to a new and decidedly adverse situation. From long depending, in considerable measure, on his physical powers, man came to trust more fully than before in his mental faculties, the result being a much greater variation in the size and activity of his brain than in other portions of his physical structure. While it had become more difficult to find and capture food animals, he was at the same time in greater danger from carnivorous beasts, which were forced by partial starvation to overcome their dread of man. He was thus obliged to become as alert and ready in defence as he was in attack, to associate himself more fully with his fellows in his hunting excursions and his other labors, and to adapt the forms and forces of nature still more to his needs, his career as a tool-making animal being greatly stimulated by the necessities of his situation.