Evelyn Reed 1963

New Light on the Origins of Man

Source: International Socialist Review, Vol. 24, No. 3, Summer 1963, pp. 81-83;
Transcribed: by Daniel Gaido;
Proofed: and corrected by Chris Clayton;
Public Domain: this text is free of copyright.

Darwin and his contemporaries demonstrated that the human species emerged out of a branch of the anthropoids. But they did not adequately explain in what way and by what means this transformation was effected. In their day very few fossil specimens were available.

Since then a far greater amount of fossil evidence has been accumulated which has filled many blank spaces in the record of mankind’s evolution. Until lately, the biggest question mark has hung over the most crucial juncture — that borderline where our primate ancestors passed over into humankind.

Each new discovery of the fossil bones of ancient creatures has aroused the hope that the main “missing link” in the chain of transitional forms from ape to man had been found and the secret of how this occurred would at last be disclosed.

Recently, the most remarkable findings in this field have been made by the British anthropologists, Dr. L.S.B. Leakey and his wife Mary, who have been working for over 30 years in East Africa. Since 1948 they have discovered and dated three anatomical specimens which span a period of perhaps 40 million years. These have been named Proconsul, Kenyapithecus and Zinjanthropus. Each represents a link in the chain of evolution toward mankind.

Proconsul, the oldest of the three fossils, found in Kenya in 1948, was a primitive ape that lived from 25 to 40 million years ago. The Leakeys regard this as the root stock of all the higher primates, including the primate branch that led to man. Kenyapithecus, the second oldest fossil, is also an ape which existed 14 million years ago. While both of these creatures have physical characteristics “leading straight in man’s direction,” they are strictly animal.

The third fossil, Zinjanthropus, was unearthed at the eroded site of a prehistoric lake at Olduvai Gorge in Tanganyika in 1959. The youngest of the three, this fossil has created the greatest stir because it was found to be not an ape, but a hominid. (The term “hominid” is the scientific designation for man in the sub-human stage of development, before reaching full-fledged stature as Homo sapiens.)

At first the Leakeys estimated that Zinjanthropus lived some 600,000 years ago. Now, through a new and more precise method of radioactive dating, this hominid is ascertained to be 1,750,000 years old. Since man had previously been considered to be no more than one million years old, this new finding pushes back the age of man by an additional three-quarter of a million years.

Zinjanthropus is not the only fossil hominid discovery. Quite a number of such specimens have been assembled in museums, marking the milestones of hominid development toward full man. The most ancient specimens of the Australopithecus or Paranthropus genus were dug up earlier in this century by Professors Dart and Broom in South Africa.

But Zinjanthropus (“East Africa Man”) is distinguished from all others by the fact that he is the oldest “true” man to be discovered. Unlike other “Dawn Men,” his hominid status is not in doubt; he unambiguously belongs to the human side of the Great Divide.

The Decisive Evidence

By what scientific test has this fossil been certified as human and not ape? Although, as Leakey points out, Zinjanthropus shows more than 20 points of physical difference from the Australopithecines, these biological changes do not suffice to qualify him unquestionably as a human. The decisive evidence has been provided not by any feature of his body, but by something outside the body. Fossil tools were dug up along with his fossil bones. These tools, which Zinjanthropus himself fashioned and used, fixes his place as the first hominid.

Earlier attempts to draw the dividing line between human and ape by means of purely physical criteria, such as the size of the brain, the peculiarities of the teeth, etc., have not worked out in practice, says Leakey. The only satisfactory fundamental criterion for distinguishing man from ape is tool-making. He and other authorities have today adopted the definition first formulated by Benjamin Franklin that “man is a tool-making animal.”

Tools, rather than skulls and bones, provide the most reliable evidence for the birth of mankind because in that distant period when the hominid was just emerging from the shell of animality, his anatomy still remained more ape-like than human. The first hominids acted in a human way long before they acquired the full human build and physical features. Thus the presence of tools is the only sure sign that the transition from apehood to manhood has taken place.

Even in the absence of hominid bones, the existence of the earliest men can be ascertained from the presence of tools. This is an advantage for anthropology, since ancient tools or artifacts are found in much greater abundance than fossil bones or skulls. As Dr. William Howells of the American Museum of Natural History puts it:

“These artifacts serve as the footprints of early man, so that his presence anywhere can be detected even though his fossil bones are extremely rare.” (Mankind So Far p. 118)

It would be better to say that early man has left his “handprints” on the sands of time, for he made the tools with his hands and wielded them with his hands. These extracorporeal instruments (cutting edge of a chipped stone, pointed end of digging stick, etc.) replaced the functions and extended the powers of the anatomical organs: arm, hand, fingernails.

The crucial importance of tool evidence in the study of human origins has focused increasing attention upon the part played by the hand in the making of man. Obviously, the hand, the eye, and the brain cooperate in the making and using of tools. But which of these indispensable anatomical organs blazed the trail toward humanity?

Until now, there has been an unresolved controversy on this matter between two schools of thought, one of which regards the hand as the key organ while the other gives precedence to the brain. Both agree that the primate out of which man directly ascended had a better developed brain and a more perfectly formed hand than all other primates. While existing ape species exhibit a lack of development or atrophy of the thumb, our primate progenitor must have possessed a near-human hand with opposable thumb. Both schools also recognize that all the anatomical improvements required for the making of man, such as upright posture, emancipated hand, enlarged brain, stereoscopic vision and vocal organs, were intimately interconnected and depended one upon the other for their functioning and growth. But they have disagreed on which was the key factor leading all the rest toward man.

Hand or Brain?

Since Darwin’s day the majority of scientists has selected the brain, and along with it man’s capacities for speech, thought and culture, as marking the fundamental distinction between man and ape. In the 19th century the British biologist Thomas H. Huxley said, “the possession of articulate speech is the grand distinctive character of man.” (Man’s Place in Nature: p. 124) His grandson of the 20th century, Julian Huxley, expounds the same proposition:

“The first and most obviously unique characteristic of man is his capacity for conceptual thought; if you prefer objective terms you will say his employment of true speech, but that is only another way of saying the same thing.” (Man in the Modern World: p. 8)

It is obvious that brain expansion has helped endow mankind with exceptional powers not shared by the animals, such as speech, generalized thought, and culture. But how and why did the brain of man develop so far beyond that of all the other species.

The late Harvard professor, Dr. Ernest Hooten, sought to answer this question by asserting that some ape “blundered” into intellectuality. Since there must have been specific causes for the creation and promotion of intelligence in our ape ancestor, this method of explanation by sheer accident is not valid.

The opposing school, by pinpointing the part played by the hand, goes to the heart of this problem. The emancipated hand with its flexible fingers and opposable thumb enabled our primate progenitors to carry out operations impossible to other species. Thereby the brain itself grew in size and capacities. Edward B. Tyler, one of the founders of anthropology, pointed this out in the last century:

“It is plain that man’s hand, enabling him to shape and wield weapons and tools to subdue nature to his own ends, is one cause of his standing first among animals. It is not so obvious, but it is true, that his intellectual development must have been in no small degree gained by the use of his hands.” (Anthropology: p. 43-44)

In his book Arboreal Man the British anatomist F. Wood Jones writes:

“It is the freed and sensitive hand which now, so to speak, goes in advance of the animal and feels its way as it climbs through life ... Tactile impressions gained through the hand are therefore perpetually streaming into the brain ... and new avenues of learning about its surroundings are being opened up ... With the development of the power of grasp, new and great possibilities come in ... Much may be learned of an object that may be grasped, lifted and examined in the hands ... Its whole outline, the texture of its surface, its hardness or softness, its size, temperature and weight can all be ascertained.” (p. 160)

Dr. Howells likewise connects the expansion of the intellect with the variegated activities of the hand:

“A true hand can open and shut, turn and twist, push and pull, all with greater facility than a pair of jaws, and all in greater coordination with the eyes. This jack-of-all-trades gives the brain a larger field of activity and more complicated functions to perform.” (Op. Cit.: p. 92)

Dr. Frederick Tilney was a world-renowned authority on the brain and its history. Yet he, too, agreed that the hand is the key to human brain development:

“From first to last it has been the achievements of his hands which have carried man onward from the time when he began to work with the simplest of stone implements ... The hand became the master key opening all the ways leading through that new and vast domain of human behavior.” (The Brain from Ape to Man: p. 54)

The opinion of these diverse scholars that the hand had priority over the brain in leading the way toward humanity is today borne out through closer study of the fossil hominids themselves. The various organs of the human body have developed at unequal rates. In the earlier stages, the skull and mental capacities lagged behind the development of hands and limbs. W.E. Le Gros Clark, anatomy professor of the University of Oxford, writes:

“It is clear that ... the evolution of the Hominoidea had led to the development of limbs approximating to the human type, even though the brain was comparatively small. In other words, the evolutionary development of the limbs appears to have outstripped the brain.” (History of the Primates: p. 72)

On the same point Dr. Howells states:

“Tooth reduction, brain increase and the straightening of posture did not all proceed at the same pace. The plainest example is to be seen in the difference between limbs and skull forms ... Our forebears were more human below the neck than above it.” (Op. Cit.: p. 129)

Although in the beginning it was the activities of the hand that awakened the brain and accelerated its mental powers, at a later stage in evolution the brain took commanding place over the hand. Men today make machines which take over not only many functions of hand labor but even of brain work. In the future society, computers and automatic devices will perform more and more of the gross forms of physical and mental labor. But in probing for human origins, the higher stages in the evolutionary process should not be confused with their starting points.

The hand led the way to the tool and with the first artifacts the human species was born. Regardless of the size of his brain, Zinjanthropus, as “the oldest well-established toolmaker ever found anywhere” (Leakey), is incontestably human. The accumulating data derived from the fossil record has induced more and more scholars to conclude that the human brain is not the cause but the consequence of the making and use of tools.

The chief American spokesmen for this view are Sherwood L. Washburn and F. Clark Howell of Chicago. They write:

“... man was often defined on the basis of the brain size. It was also often implied that such forms had discovered culture as we know it bit by bit. It would now appear, however, that the large size of the brain of certain hominids was a relatively late development ... after bipedalism and consequent upon the use of tools. The tool-using, ground-living, hunting way of life created the large human brain rather than a large-brained man discovering new ways of life. The authors believe this conclusion is the most important result of the recent fossil hominid discoveries, and is the one which carries far-reaching implications for the interpretation of human behavior and its origins ... The important point is that size of brain ... has increased threefold subsequent to the use and manufacture of tools.” (Evolution After Darwin: p. 49-51)

Dr. Leakey assigns the same precedence to tool-making:

“Once scientists used the size of the brain case or the ability to walk upright with the hands free, or even the power of speech, as characteristics that distinguish Homo sapiens from anthropoid apes. Recently, however, we have tended to define man by means of the tool-making ability.” (National Geographic Magazine, Sept. 1960)

From Tools to Labor

Those anthropologists who regard tool making as the authentic badge of humankind have taken a long step toward the position of the historical materialists. They fall short, however, by failing to make explicit the vital connection between tools and laboring activity.

Tools are the products of labor as well as the instruments of labor. Since Zinjanthropus made tools according to a set pattern, this signifies he was engaged in systematic labor activities. He was no longer merely collecting what nature yielded for his subsistence — he was producing the necessities of life for himself and his kind. Together, they regularly worked for a living.

To depend upon production for the necessities of life, and to fabricate implements for that purpose, is the mode of survival and development peculiar to the human species alone. Man, the Toolmaker, can more precisely be defined as Man, the Laborer. Indeed, many archaeologists recognize that Homo faber (working man) is the predecessor of Homo sapiens (intelligent man).

Zinjanthropus does more than supply fossil evidence of that crucial turning point in evolution where the ape left off and the human began. When the petrified remains of his bones and tools are reanimated and viewed as elements in the dynamics of the living labor process, Zinjanthropus also discloses that the factor of labor is the definitive “missing link” in the birth of mankind.


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