Primitive Man

in The Evolution of Man

Grafton Elliot Smith 1924

[2]

 

Figure 1. A tentative scheme of the relations of the different genera, species, and races of the Human Family.

 

[60] The discovery of the remains of the Piltdown Man is perhaps the most remarkable episode in the whole history of anthropology. For it is a very singular coincidence that this wonderful skull should have come to light in the county of Sussex, within a few miles of the place where Huxley spent the last days of a life which was largely devoted to the task of convincing [87] his fellows that some such creature must have existed in the distant past. It represents the most primitive member of the Human Family, excepting only the ape-like Javan fossil Pithecanthropus, which, as I have already mentioned, some leading palaeontologists still regard, not as one of the Hominidae, but as a giant Ape. But, for the reasons which I have explained above, Pithecanthropus was truly a member of our family. It was provided with a brain of very small dimensions, which nevertheless was much too large to have been an Ape's.

The 'Dawn Man' of Piltdown, however was provided with a brain that, though small, comes definitely within the range of variation in size found in modern Man. But there are clear indications that mere volume of brain is not the only criterion of mental superiority. Those parts of the organ which develop latest in ourselves were singularly defective in Eoanthropus. Associated with the essentially human brain-case was a jaw which at first sight seemed to be as definitely simian. In fact certain palaeontologists still persist in claiming that the jaw is a chimpanzee's and did not belong to the human skull with which it was found. But this claim ignores, not merely the improbability of such a chance association on the same spot of the remains of a hitherto unknown man-like Ape and an equally unknown ape-like Man, one of which left his skull without the jaw and the other the jaw without the skull, but also the large series of anatomical peculiarities of the jaw and teeth which prove the jaw to be, not a chimpanzee's, but that of a primitive human being–no doubt a part of the same individual whose skull was deposited alongside it. The outstanding interest of the Piltdown skull is the confirmation it affords of the view that in the evolution of Man the brain led the way. It is the veriest truism that Man has emerged from the simian state in virtue of the enrichment of the structure of his mind. It is singular that so much biological speculation has neglected to [68] give adequate recognition of this cardinal fact. The brain attained what may be termed the human rank at a time when the jaws and face, and no doubt the body also, still retained much of the uncouthness of Man's simian ancestors. In other words, Man at first, so far as his general appearance and 'build' are concerned, was merely an Ape with an overgrown brain. The importance of the Piltdown skull lies in the fact that it affords tangible confirmation of these inferences.

Figure 10. Drawing of the left side of Professor John I. Hunter's reconstruction of the Piltdown skull, by L. T. Poulton.

Not long after the Piltdown race made its way into [69] England – or according to some writers even before it did so–another member of the Hominidae invaded Germany. All that is known of it is the massive brutal jaw found in the Mauer Sands near Heidelberg. In spite of its antiquity and its large proportions, the form of this mandible, and especially the teeth lodged in it, approximate much more closely to the recognized human standard than do those of Eoanthropus.

For a vast span of time after these two divergent human genera left their bodily remains respectively near Piltdown and Heidelberg, nothing whatever is known of the history of mankind except the evidence supplied by innumerable flint implements. When tile curtain is rung up again we find Europe in the occupation of the genus Homo, though not of our species. For Neanderthal Man was now in possession. What was the fate of Eoanthropus and Heidelberg Man is quite unknown. It is claimed by some writers that Neanderthal Man is merely the modified descendant of Heidelberg Man, but the reasons given for this belief are unsubstantial and unconvincing.

It is highly probable that the Neanderthal race entered Europe from Africa by way of tile Iberian peninsula.

Somewhere in Africa or Asia it was evolved from tile common stock which also gave birth to the men of Piltdown and Heidelberg at a much earlier period.

The large series of skeletal remains that have now been recovered, and in particular the skeleton * found in 1908 in a grotto near La Chapelle-aux-Saints by the Abbes A. and J. Bouyssonnie, affords a clear-cut picture of the uncouth and repellent Neanderthal Man. His short, thick-set, and coarsely built body was carried in a half-stooping slouch upon short, powerful, and half

* A masterly account of these remains and their significance has been given by Professor Marcellin Boule in the Annales de Paléontologie, 1911, 1912, and 1913. See also his book Fossil Men (English translation of Les Hommes fossiles ), London, 1923.

[70] flexed legs of peculiarly ungraceful form. His thick neck sloped forward from the broad shoulders to support tile massive flattened head, which protruded forward, so as to form an unbroken curve of neck and back, in place of the alternation of curves which is one of the graces of the truly erect Homo sapiens. The heavy overhanging eyebrow-ridges and retreating forehead, tile great coarse face with its large eyesockets, broad nose, and receding chin, combined to complete tile picture of unattractiveness, which it is more probable than not was still further emphasized by a shaggy covering of hair over most of the body. The arms were relatively short, and the exceptionally large hands lacked the delicacy and the nicely balanced co-operation of thumb and fingers which is regarded as one of the most distinctive of human characteristics.

The contemplation of all these features emphasizes the reality of the fact that the Neanderthal Man belongs to some species other than Homo sapiens. . . .

[85]

[Pithecanthropus, Eoanthropus, Homo Rhodesiensis]

Figure 12. Endo-cranial casts of the three most primitive members of the Human Family, drawn by T. L. Poulton, to indicate that the newly expanded cortical areas are those which are most feebly developed in the primitive type of Man and undergo progressive expansion.

The Origin of Man

The Evolution of Man: 1924

G. Elliot Smith

PIX

 

 

 

[2] Figure 1. A tentative scheme of the relations of the different genera, species, and races of the Human Family.

[35] The Origin of Man

It is the last stage in the evolution of Man that has always excited chief interest and has been the subject of much speculation.

These discussions usually resolve themselves into [36] the consideration of such questions as whether it was the growth of the brain, the acquisition of the power of speech, or the assumption of the erect attitude that came first and transformed an ape into a human being. The case for the erect attitude was ably put by Dr. Munro in 1893. 1 He argued that the liberation of the hands and the cultivation of their skill lay at the root of man's mental supremacy.

If the erect attitude is to explain all, why did not the Gibbon become a man in Miocene times or earlier? The whole of my argument has aimed at demonstrating that it is the steady growth and specialization of the brain that has been the fundamental factor in leading Man's ancestors step by step upward from the lowly Insectivore status, and through every earlier phase in the evolution of Mammals–for Man's brain represents the consummation of precisely those factors which throughout the Vertebrata have brought their possessors to the crest of the wave of progress. But such advances as the assumption of the erect attitude are brought about simply because the brain has made skilled movements of the hands possible and of definite use in the struggle for existence. Yet once such a stage had been attained, the very act of liberating the hands for the performance of more delicate movements opened the way for a further advance in brain development to make the most of the more favourable conditions and the greater potentialities of the hands.

It is a fact beyond dispute that the divergent specialization of the human limbs–one pair for progression and the other for prehension–and the more delicately adjusted skilled action, has played a large part in preparing the way for the emergence of the distinctly human characteristics; but it would be a fatal mistake unduly to magnify the influence of these developments. Such a primitive member of the Primates as the Spectral Tarsier can assume the erect [37] attitude and use its hands for prehension rather than progression, and many other Lemurs, such as the Indrisinae of Madagascar, can and do walk erect.

In the remote Oligocene, a Catarrhine ape, nearly akin to the ancestors of the Indian sacred monkey, Semnopithecus, became definitely specialized in structure in adaptation for the assumption of the erect attitude. This type of early anthropoid has persisted with relatively slight modifications in the Gibbon of the present day. But if the earliest Gibbons were already able to walk upright, how is it, one might ask, that they did not begin to use their hands, thus freed from the work of progression on the earth, for skilled work, and at once become men? The obvious reason is that the brain had not yet attained a sufficiently high stage of development to provide skilled work, apart from the tree climbing, of biological usefulness for these competent hands to do.

The Ape is tied down absolutely to his experience and has only a very limited ability to anticipate the results even of relatively simple actions, because so large a proportion of his neopallium is under the dominating influence of the senses. Without a fuller appreciation of the consequences of its actions than the Gibbon is capable of, the animal is not competent to make full use of the skill it undoubtedly possesses. What is implied in acquiring this fuller appreciation of the meaning of events taking place around the animal? The state of consciousness awakened by a simple sensory stimulation is not merely an appreciation of the physical properties of the object that supplies the stimulus; the object simply serves to bring to consciousness the results of similar or contrasted experiences in the past, as well as the feelings aroused by or associated with them, and the acts such feelings excited. This mental enrichment of a mere sensation so that it acquires a very precise and complex meaning is possible only because the individual has this extensive experience to fall back upon; and [38] the faculty of acquiring such experience implies the possession of large neopallial areas for recording, so to speak, these sensation factors and the feelings associated with them. The 'meaning' which each creature can attach to a sensory impression presumably depends, not on its experience only, but more especially upon the neopallial provision in its brain for recording the fruits of past experience.

Judged by this standard, the human brain bears ample witness, in the expansion of the great temporo-parietal area, which so obviously has been evolved from the regions into which visual, auditory, and tactile impulses are poured, to the perfection of the physical counterpart of the enrichment of mental structure, which is the fundamental characteristic of the human mind.

The second factor that came into operation in the evolution of the human brain is merely the culmination of a process which has been steadily operating throughout the Primates. I refer to the high state of perfection of the cortical regulation of skilled movements, many of which are acquired by each individual in response to a compelling instinct that forces every normal human being to work out his own salvation by perpetually striving to acquire such manual dexterity.

This brings us to the consideration of the nature of the factors that have led to the wide differentiation of Man from the Gorilla. Why is it that these two Primates, structurally so similar and derived simultaneously from common parents, should have become separated by such an enormous chasm, so far as their mental abilities are concerned?

There can be no doubt that this process of differentiation is of the same nature as those which led one branch of the Eocene Tarsioids to become monkeys, while the other remained Prosimae; advanced one group of primitive monkeys to the Catarrhine status, [39] while the rest remained Platyrrhine; converted one division of the Old World Apes into Anthropoids, while the others retained their old status. Put into this form as an obvious truism, the conclusion is suggested that the changes which have taken place in the brain to convert an Ape into Man are of the same nature as, and may be looked upon merely as a continuation of, those processes of evolution which we have been examining in the lowlier members of the Primate series. It was not the adoption of the erect attitude that made Man from an Ape, but the gradual perfecting of the brain and the slow upbuilding of the mental structure, of which erectness of carriage is one of the incidental manifestations.

The ability to perform skilled movements is conducive to a marked enrichment of the mind's structure and the high development of the neopallium, which is the material expression of that enrichment. There are several reasons why this should be so. The mere process of learning to execute any act of skill necessarily involves the cultivation, not only of the muscles which produce the movement, and the cortical area which excites the actions of these muscles, but in even greater measure the sensory mechanisms in the neopallium which are receiving impressions from the skin, the muscles, and the eyes, to control the movements at the moment, and incidentally are educating these cortical areas, stimulating their growth, and enriching the mental structure with new elements of experience. Out of the experience gained in constantly performing acts of skill the knowledge of cause and effect is eventually acquired. Thus the high specialization of the motor area, which made complicated actions possible, and the great expansion of the temporo-parietal area, which enabled the Ape-Man to realize the 'meaning' of events occurring around it, reacted one upon the other, so that the creature came to understand that a particular act would entail certain consequences. In [40] other words, it gradually acquired the faculty of shaping its conduct in anticipation of results.

Long ages ago, possibly in the Miocene (see Figure 2), the ancestors common to Man, Gorilla, and Chimpanzee became separated into groups. The different conditions to which they became exposed after they parted company were in the main responsible for the contrasts in their fate. In one group the distinctively Primate process of growth and specialization of the brain, which had been going on in their ancestors for many thousands, even millions, of years, reached a stage when the more venturesome members of the group–stimulated perhaps by some local failure of the customary food, or maybe led forth by a curiosity bred of their growing realization of the possibilities of the unknown world beyond the trees, which hitherto had been their home–were impelled to issue forth from their forests, and seek new sources of food and new surroundings on hill and plain, wherever they could obtain the sustenance they needed. The other group, perhaps because they happened to be more favourably situated or attuned to their surroundings, living in a land of plenty, which encouraged indolence in habit and stagnation of effort and growth, were free from this glorious unrest, and remained apes, continuing to lead very much the same kind of life (as Gorillas and Chimpanzees) as their ancestors since the Miocene or even earlier times. That both of these unenterprising relatives of Man happen to live in the forests of tropical Africa has always seemed to me to be a strong argument in favour of Darwin's view that Africa was the original home of the first creatures definitely committed to the human career; for while Man was evolved amidst the strife with adverse conditions, the ancestors of the Gorilla and Chimpanzee gave up the struggle for mental supremacy because they were satisfied with their circumstances; and it is more likely than not that they did not change their habitat.

[41] The erect attitude, infinitely more ancient than man himself, is not the real cause of Man's emergence from the simian stage; but it is one of the factors made use of by the expanding brain as a prop still further to extend its growing dominion, and by fixing and establishing in a more decided way this erectness it liberated the hand to become the chief instrument of Man's further progress.

In learning to execute movements of a degree of delicacy and precision to which no ape could ever attain–and the primitive Ape-Man could only attempt once his arm was completely emancipated from the necessity of being an instrument of progression–the cortical area that is pre-eminently concerned with the phenomena of attention 2 became enhanced in importance. Hence the prefrontal region, where the activities of the cortex as a whole are, as it were, focused and regulated, began to grow until eventually it became the most distinctive characteristic of the human brain, gradually filling out the front of the cranium and producing the distinctively human forehead. In the diminutive prefrontal area of Pithecanthropus 3 and, to a less marked degree, Neanderthal Man, 4 we see illustrations of lower human types, bearing the impress of their lowly state in receding foreheads and great brow ridges. However large the brain may be in Homo neanderthalensis, his small prefrontal region is sufficient evidence of his lowly state of intelligence and reason for his failure in the competition with the rest of mankind.

The growth in intelligence and in the powers of discrimination no doubt led to a definite cultivation of the aesthetic sense, which, operating through sexual [42] selection, brought about a gradual refinement of the features, added grace to the general build of the body, and demolished the greater part of its hairy covering. It also led to an intensification of the sexual distinctions, especially by developing in the female localized deposits of fatty tissue, not found in the apes, which produced profound alterations in the general form of the body.

Right-handedness

To one who considers what precisely it means to fix the attention and attempt the performance of some delicately adjusted and precise action, it must be evident that one hand only can be usefully employed in executing the consciously skilled part in any given movement. The other hand, like the rest of the muscles of the whole body, can be only auxiliary to it, assisting, under the influence of attention, either passively or actively, in steadying the body or helping the dominant hand. Moreover, it is clear that if one hand is constantly employed for doing the more skilled work, it will learn to perform it more precisely and more successfully than either would if both were trained, in spite of what ambidextral enthusiasts may say. Hence it happened that when Nature was fashioning Man the forces of natural selection made one hand more apt to perform skilled movements than the other. Why precisely it was the right hand that was chosen in the majority of mankind we do not know, though scores of anatomists and others are ready with explanations. But probably some slight mechanical advantage in the circumstances of the limb, or perhaps even some factor affecting the motor area of the left side of the brain that controls its movements, may have inclined the balance in favour of the right arm; and the forces of heredity have continued to perpetuate a tendency long ago imprinted in Man's structure when first he became human.

[43] The fact that a certain proportion of mankind is left-handed, and that such a tendency is transmitted to some only of the descendants of a left-handed person, might perhaps suggest that one half of mankind was originally left-handed and the other right-handed, and that the former condition was recessive in the Mendelian sense, or that some infinitesimal advantage may have accrued to the right-handed part of the original community, which in time of stress spared them in preference to left-handed individuals; but the whole problem of why right-handedness should be much more common than left-handedness is still quite obscure The superiority of one hand is as old as mankind, and is one of the factors incidental to the evolution of Man.

It is easily comprehensible why one hand should become more expert than the other, as I have attempted to show; and the fact remains that it is the right hand, controlled by the left cerebral hemisphere, which is specially favoured in this respect. This heightened educability of the (left) motor centre (for the right hand) has an important influence upon the adjoining areas of the left motor cortex. When the Ape-Man attained a sufficient degree of intelligence to wish to communicate with his fellows other than merely by instinctive emotional cries and grimaces, such as all social groups of animals employ, the more cunning right hand would naturally play an important part in such gestures and signs; and, although the muscles on both sides of the face would be called into action m such movements of the features as were intended to convey information to another (and not merely to express the personal feelings of the individual) such bilateral movements would certainly be controlled by the left side of the brain, because it was already more highly educated. . . .

[65] I have discussed these elementary psychological principles for the purpose of emphasizing the fact that Man's mental and moral attitude is, in a large measure, [66] determined by those primitive instincts and emotions which he shares with his simian ancestors, but also by the influence, conscious and unconscious, of the atmosphere of traditions amidst which he has grown up. At no stage of his career has he acquired highly complex and specialized instincts which impelled him, without any prompting from other peoples, to build megalithic monuments or to invent the story of the deluge, independently of other people who do the same arbitrary things, as modern speculations would have us believe.

It would ill become me as a biologist to attempt to minimize the vast role played by heredity in determining the physical structure and the mental and moral aptitudes of every individual, and the variations in the average levels of attainment to which these hereditary qualities are subject in different races. But it is necessary to emphasize the fact that, so far as innate mental and moral characteristics are concerned, it is merely a vaguely defined and more or less generalized aptitude that is inherited, and not any special kind of ability or congenital propensity towards good or evil behaviour.

The musical genius, however great his aptitude may be to appreciate the subtle symbolism of sound and to acquire the mechanical skill in giving appropriate expression to his knowledge and feelings, could not become a musician unless he was provided with the opportunities for learning the arbitrary conventions of music which obtain in the community where he happens to live.

The discovery of the remains of the Piltdown Man is perhaps the most remarkable episode in the whole history of anthropology. For it is a very singular coincidence that this wonderful skull should have come to light in the county of Sussex, within a few miles of the place where Huxley spent the last days of a life which was largely devoted to the task of convincing [67] his fellows that some such creature must have existed in the distant past. It represents the most primitive member of the Human Family, excepting only the ape-like Javan fossil Pithecanthropus, which, as I have already mentioned, some leading palaeontologists still regard, not as one of the Hominidae, but as a giant Ape. But, for the reasons which I have explained above, Pithecanthropus was truly a member of our family. It was provided with a brain of very small dimensions, which nevertheless was much too large to have been an Ape's.

The 'Dawn Man' of Piltdown, however, was provided with a brain that, though small, comes definitely within the range of variation in size found in modern Man. But there are clear indications that mere volume of brain is not the only criterion of mental superiority. Those parts of the organ which develop latest in ourselves were singularly defective in Eoanthropus. Associated with the essentially human brain-case was a jaw which at first sight seemed to be as definitely simian. In fact certain palaeontologists still persist in claiming that the jaw is a chimpanzee's and did not belong to the human skull with which it was found. But this claim ignores, not merely the improbability of such a chance association on the same spot of the remains of a hitherto unknown man-like Ape and an equally unknown ape-like Man, one of which left his skull without the jaw and the other the jaw without the skull, but also the large series of anatomical peculiarities of the jaw and teeth which prove the jaw to be, not a chimpanzee's, but that of a primitive human being–no doubt a part of the same individual whose skull was deposited alongside it. The outstanding interest of the Piltdown skull is the confirmation it affords of the view that in the evolution of Man the brain led the way. It is the veriest truism that Man has emerged from the simian state in virtue of the enrichment of the structure of his mind. It is singular that so much biological speculation has neglected to [68] give adequate recognition to this cardinal fact. The brain attained what may be termed the human rank at a time when the jaws and face, and no doubt the body also, still retained much of the uncouthness of Man's simian ancestors. In other words, Man at first, so far as his general appearance and 'build' are concerned, was merely an Ape with an overgrown brain. The importance of the Piltdown skull lies in the fact that it affords tangible confirmation of these inferences.


 


Figure 10. Drawing of the left side of Professor John I. Hunter's reconstruction of the Piltdown skull, by L. T. Poulton.

 

Not long after the Piltdown race made its way into [69] England–or according to some writers even before it did so–another member of the Hominidae invaded Germany. All that is known of it is the massive brutal jaw found in the Mauer Sands near Heidelberg. In spite of its antiquity and its large proportions, the form of this mandible, and especially the teeth lodged in it, approximate much more closely to the recognized human standard than do those of Eoanthropus .

For a vast span of time after these two divergent human genera left their bodily remains respectively near Piltdown and Heidelberg, nothing whatever is known of the history of mankind except the evidence supplied by innumerable flint implements. When the curtain is rung up again we find Europe in the occupation of the genus Homo, though not of our species. For Neanderthal Man was now in possession. What was the fate of Eoanthropus and Heidelberg Man is quite unknown. It is claimed by some writers that Neanderthal Man is merely the modified descendant of Heidelberg Man, but the reasons given for this belief are unsubstantial and unconvincing.

It is highly probable that the Neanderthal race entered Europe from Africa by way of the Iberian peninsula.

Somewhere in Africa or Asia it was evolved from the common stock which also gave birth to the men of Piltdown and Heidelberg at a much earlier period.

The large series of skeletal remains that have now been recovered, and in particular the skeleton5 found in 1908 in a grotto near La Chapelle-aux-Saints by the Abbés A. and J. Bouyssonnie, affords a clear-cut picture of the uncouth and repellent Neanderthal Man. His short, thick-set, and coarsely built body was carried in a half-stooping slouch upon short, powerful, and half-[70]flexed legs of peculiarly ungraceful form. His thick neck sloped forward from the broad shoulders to support the massive flattened head, which protruded forward, so as to form an unbroken curve of neck and back, in place of the alternation of curves which is one of the graces of the truly erect Homo sapiens. The heavy overhanging eyebrow-ridges and retreating forehead, the great coarse face with its large eyesockets, broad nose, and receding chin, combined to complete the picture of unattractiveness, which it is more probable than not was still further emphasized by a shaggy covering of hair over most of the body. The arms were relatively short, and the exceptionally large hands lacked the delicacy and the nicely balanced co-operation of thumb and fingers which is regarded as one of the most distinctive of human characteristics.

The contemplation of all these features emphasizes the reality of the fact that the Neanderthal Man belongs to some other species than Homo sapiens.

Many recent writers have been puzzled to account for the great size of his brain, seeing that the average capacity of the Neanderthal cranium exceeds that of modern Europeans. But, as I shall have occasion to point out later on, the development of the brain of Neanderthal Man was partial and unequal. That part of the organ which plays the outstanding part in determining mental superiority was not only relatively, but actually, much smaller than it is in Homo sapiens. The large size of the Neanderthal brain was due to a great development of that region which was probably concerned primarily with the mere recording of the fruits of experience, rather than with the acquisition of great skill in the use of the hand and the attainment of the sort of knowledge that comes from manual experiment.

The discovery of this species thus revealed the former existence of a type of mankind which, in spite of its great size of brain, is clearly on a lower plane than its successors whom it is customary to include within the genus sapiens. . . .

______________________________________________________________________________

 

1 Munro, 'Address to the British Association'.

2 In a later chapter this will be further elucidated.

3 Eug. Dubois, 'Remarks upon the Brain-cast of Pithecanthropus, Proc. Fourth Internat. Cong. Zool., August 1898, published in Cambridge, 1899, p. 8I.

4 Boule and Anthony, 'L'encephale de l'homme fossile de la Chapelle-aux-saints', L'Anthropologie, tome 22, No. 2, 1911, p. 50.

5 A masterly account of these remains and their significance has been given by Professor Marcellin Boule in the Annales de Paléontologie , 1911, 1912, and 1913. See also his book Fossil Men (English translation of Les Hommes fossiles ), London, 1923.