§ 2 What the Hypothesis Explains
Let me run rapidly through the chief differences between Man and his nearest congeners: some of them are obvious and can be stated very briefly; others I shall return to in the next chapter. We shall see that they all follow naturally from the above hypothesis.
(1) The anthropoids are never found out of the tropical forests of Africa and Malaya (including Borneo and Sumatra). They feed chiefly on the fruits and other highly nutritious vegetable products that, all the year round, are only there obtainable. Although often coming to the ground, especially the chimpanzee and gorilla, they are adapted to living in the trees: that is their home. In contrast with their habits, Man is at home on the ground, with unlimited range over the whole planet from beyond the Arctic Circle to Tasmania and Tierra del Fuego; because on the ground (chiefly) he everywhere finds his food in the other animals whom he hunts and slays. This, then, is the condition of his emancipation from the tropical forest. It is, indeed, conceivable that a frugivorous animal, originally of the forest, should obtain a wider range by taking to a coarser diet of roots and herbage, such as suffices the Ungulates, browsing or grazing or digging with their snouts; but this would not have led to the upright gait, or the big brain, or any of the marks that distinguish Man. Not advance but retrogression must have followed such a change.
(2) That the earliest men of whose condition of life we have any knowledge were hunters agrees with the hypothesis. Any other view of Man’s origin must explain how and when he became a hunter. There seems to be no reason to put the change of habits (which certainly occurred at some time) anywhere nearer than the beginning of our differentiation. The further we put it back the better it explains other modifications.
(3) The erect attitude was reached by the apes in the course of adaptation to arboreal life;4 but the erect gait as the normal mode of progression is (if we neglect the gibbons’ imperfect performance) peculiar to ourselves; and such a gait was attained because the most successful hunters followed their prey afoot upon the ground. The feeble ineffective shuffle of the anthropoids upon the ground, supporting themselves with their arms where there are no overhanging boughs to swing by and help themselves along, could not have served the hunter, especially if he was to leave the forest. We may, indeed, suppose that at first prey was sometimes attacked by leaping upon it from the branch of a tree, as leopards sometimes do; but the less our ancestor in his new career trusted to trees the better for him. Such simple strategy could not make him a dominant animal throughout the world; nothing could do this but the gradual attainment of erect gait adapted to running down his prey. Hence the numerous modifications of structure necessary to it, whenever from time to time they occurred, were preserved and accumulated by natural selection: namely, the curving of the vertebral column, the balancing of the head upon a relatively slender neck, changes in the joints, bones and muscles of the legs, the lengthening of the leg and the specialisation of the foot (in which the heel is developed more than in the gorilla, and the great toe is lengthened and lies parallel with the other toes).
(4) The specialisation of the legs and feet, as it proceeded, made possible the specialisation of the hands: being gradually rid of the task of assisting locomotion, whether in trees or on the ground, they were used in grappling with prey, seconded by massive jaws and powerful canine teeth. In course of time they brought cudgels and stones to the encounter, and after many ages began to alter such means of offence into weapons that might be called artefacts. These simple beginnings probably occupied an immense time, perhaps more than half of the total period down to the present. The utility and consequent selection of hands had been great throughout; but their final development may be referred to the making and using of weapons fashioned according to a mental pattern. Those who had the best hands were selected because they made the best weapons and used them best; but we know from remains of several palæolithic stages of the art of manufacturing implements how very slowly the art improved.
(5) Along with specialisation of the hands went a reduction in the length and massiveness of the arms; and this must have been disadvantageous in directly grappling with prey. But it was necessary to the runner in order to lessen the weight and cumbersomeness of the upper part of the body and to improve his balance and agility. The change may also have been beneficial by affording physiological compensation for the lengthening and strengthening of the legs. And as soon as unwrought stones and clubs came into use there was mechanical compensation for the shortening of the arms. The result is an adaptive co-ordination of the total structure to the life of a two-footed hunter.
(6) Darwin says: “The early male forefathers of Man were, as previously stated, probably furnished with great canine teeth; but as they gradually acquired the habit of using stones, clubs, or other weapons, for fighting with their enemies or rivals, they would use their jaws and teeth less and less. In this case the jaws, together with the teeth, would become reduced in size, as we may feel almost sure from numerous analogous cases.”
(7) Hence the profile began to approach the orthognathous type; and it progressed further in that direction on account of accompanying changes in the skull. The skull became less thick and rough, (a) because, as the hands (using weapons) superseded the teeth in fighting, jaws and neck grew less massive, and their muscles no longer needed such solid attachments; (b) because the head was less liable to injury when no longer used as the chief organ in combat. At the same time the skull slowly increased in capacity and became vaulted to make room for the brains of an animal, which (as we shall see) acquired much knowledge (parietal association area) and lived by the application of its knowledge to the co-ordination of increasingly complex and continuous activities (anterior association area).5
(8) Monkeys of most species, whether in the New World or in the Old, are social, living in bands of from ten to fifty or more, and may co-operate occasionally in mutual defence or in keeping watch. Baboons, indeed, are seen in herds of several hundreds; and they are credibly reported to co-operate in raiding plantations, and in defending themselves against leopards, other baboons and even human hunters.6 Gibbons, again, are social, going in bands to the number of fifty. But the large anthropoids live only in families—the male orang being even of a somewhat solitary habit; three or four families of chimpanzees may for a time associate together. Man, however, is everywhere—with a few doubtful exceptions, probably degenerate—both social and co-operative; and the purpose of his co-operation at the level of the Australian or the Semang is instructive. It is not, as we might suppose, in industry, but in hunting, war, or tribal ceremonies that tribesmen work together—the last no doubt of comparatively recent origin: so that a few thousand years ago there was no co-operation except hunting and war (which come to the same thing).
That the large anthropoids are neither gregarious nor co-operative follows from their having no task in which co-operation would be useful, no common purpose: they are able alone to defend themselves and their families; and when families range apart through the woods their food is in better supply. But the ancestor of Man found an object for association and co-operation in the chase. Spencer, indeed, says that a large carnivore, capable of killing its own prey, profits by being solitary; and this may be true where game is scarce: in the Oligocene and Miocene periods game was not scarce. Moreover, when our ape first pursued game, especially big game (not being by ancient adaptation in structure and instinct a carnivore), he may have been, and probably was, incapable of killing enough prey single-handed; and, if so, he will have profited by becoming both social and co-operative as a hunter, like the wolves and dogs—in short, a sort of wolf-ape (Lycopithecus). The pack was a means of increasing the supply of food per unit; and gregariousness increased by natural selection up to the limit set by utility. Hence (as will be shown at length in the next chapter) Man is in character more like a dog or a wolf than he is like any other animal.
(9) Some development of the rudiments of speech may be confidently traced to social co-operation. The gibbon, most social, is also the most vocal of anthropoids; but having no common task in which united action is necessary, he uses his remarkable power of voice (apparently) merely to express his feelings and to keep the troop together. The chimpanzee and the gorilla enjoy probably a close and affectionate family life, but one that makes little or no demand for concerted effort. Hence their vocalisation is very rudimentary. According to R. L. Garner, it is true speech: a chimpanzee (he says) knows the meaning of the sounds he makes, and intends to convey it to some definite individual at whom he looks. But he has at command very few sounds, and those mainly expressive of natural wants.7 If it be urged that anthropoids do not talk because their lower jaw and tongue have not the special adaptation to speech that is found in Man, it should be considered (a) that if such structure had been useful to them it would have been acquired, as at some time it must have been by Man himself; and (b) that even without any change they might have jabbered well enough to convey a good many discriminated, objective meanings if they had needed to do so: for Man must have begun in that way; he cannot have waited for the development of physical structure before trying to talk. Sufficient intelligence is not wanting to chimpanzees; for in captivity they learn to understand a good deal that is said to them. What they wanted was a sufficient motive for persistently trying to communicate, such that those who made any progress in the art had a living advantage over others. Man had such a motive; because co-operation was necessary to him, not (as we have seen) in industry, but in hunting. In hunting, in planning and directing the hunt, speech is plainly useful; and it is better than gesture, which probably preceded, and generally accompanied it; because, as speech became independent of gesture, it could go on whilst the hands and body were otherwise employed, or where comrades could not see one another—transferring, by a very profitable division of labour, the whole business of expression to organs not otherwise needed. It may not be much more than very simple beginnings of articulate speech that can be traced to early co-operative hunting; but in the beginning lies the whole difficulty. And the situation was particularly favourable to the beginning of language by onomatopœia, imitating the characteristic noises of different animals and of the weapons and actions employed in pursuing and slaying them.
(10) The intelligence and extensive knowledge (compared with anthropoids) that distinguish Man in his lowest known condition are clearly accounted for by his adoption of the hunting life. Already (as we may assume) the most intelligent of living animals, with great knowledge of the forest, he had everything to learn about the world beyond the forest as soon as he ventured into it, and everything to learn about the art of hunting. Depending chiefly upon sight and hearing, he had to learn by observation, and to remember, and to apply all and more than all that the carnivore knows and does instinctively, or learns by following its mother. He must have learned to discriminate all sorts of animals, many of them new in a strange country; their reactions to himself, manner of flight, or of attack, or defence; the spoor of each and its noises; its habits and haunts, where it reposed or went to drink, where to set snares or lie in wait for it. Advancing to the use of weapons, he must have adapted them to his prey; he must have discovered the best materials—wood, or stone, or bone—for making weapons, the best materials for snares, and where to find such things. He must have fixed in his mind this series: game, weapons, the making of them, materials, where found; and must have learned to attend to the items of the series in the necessary order without impatience or confusion: a task far beyond the power of any other animal.
Further, the hunting life supplied a stimulus that had formerly been wanting to our ape. There is some difficulty in comprehending why the anthropoid should be as intelligent as he is; and, similarly, it seemed to Wallace that the savage has intelligence above his needs—“in his large and well-developed brain he possesses an organ quite disproportionate to his actual requirements.”8 This illusion results from our not reflecting that the first task of increasing intelligence is to deal appropriately with details in greater and greater number and variety, and that the details of their life, with both savage and anthropoid, are just what we cannot appreciate. Still, the anthropoid seems to have a rather lazy time of it: especially, he seems to have hardly any occasion for following out a purpose needing some time for its accomplishment. This powerful stimulus the hunting life applies to carnivores, above all to dogs and wolves; and in the same way it affected our ape: compelling him to combine many activities for a considerable period of time, along with his fellows, and direct them to one end in the actual hunting, and (later) to prosecute still other activities for a longer period in preparing weapons and snares to make the hunting more effective. Add to these considerations the development of gesture and rudiments of speech, exacting intelligence for their acquisition and increasing intelligence by their attainment, and the superiority of the lowest savage to an anthropoid is sufficiently explained. Severe must have been the selection of those that were capable of such progress, and correspondingly rapid the advance and differentiation of the species.
(11) Using stones as weapons, and finding that broken stones do most damage, and breaking them for that purpose, the progressive hunter necessarily makes some sparks fly; and if these fall amongst dry leaves or grass, he may light a fire. “In making flint implements sparks would be produced; in polishing them it would not fail to be observed that they became hot; and in this way it is easy to see how the two methods of making fire may have originated.”9 But if the production of fire by friction had been suggested by the polishing of flints, it could hardly have been discovered before the neolithic stage; whereas hearths are known of much earlier date. And it may have happened earlier whilst some one was polishing an arrow or a spear with another piece of wood: a supposition which dispenses with the long inference from a warm flint to a flaming stick. It is a curious fact that to this day in Australia fire is sometimes made by rubbing a spear-thrower upon a shield;10 but I lay no stress upon this, as if such a practice must be traditionary from the earliest discovery of the method. Either in the chipping of flints or in the polishing of spears it is far easier, and a more probable way, to learn the art of making fire than by observing that dried boughs or bamboos driven together by the wind sometimes catch fire; because those processes include the very actions which the art employs: imitation of nature is not called for. It is true that the natives of Nukufetan in the South Seas explain the discovery of fire by their having seen smoke arise from two crossed branches of a tree shaken in the wind;11 but this, probably, is merely the speculation of some Polynesian philosopher. Volcanoes, too, have been pointed out as a possible source of fire; and, in the myth, Demeter is said to have lit her torches at the crater of Ætna—an action fit for a goddess. But were such an origin of fire conceivable with savages, it would not show how they came to make it themselves. Fire at first must have excited terror. Until uses were known for fire no one could have ventured to fetch it from a volcano, nor to make it by imitating the friction of boughs in the wind. Fires were accidentally lit by man again and again, and much damage done, before he could learn (a) the connection of events, (b) the uses of fire, (c) purposely to produce it, (d) how to control it. The second and fourth of these lessons are much more difficult than the mere making of fire; they are essential, yet generally overlooked. It seems necessary to suppose a series of accidents at each step, in order to show the effects of fire in hardening wood, hollowing wood, cooking game, baking and (later) glazing clay, and so forth. Perhaps a prairie-fire disclosed the advantages of cooking game, and many a prairie was afterwards burnt to that end before a more economical plan was discovered. As to the effect of fire on clay, Lord Avebury observes that clay-vessels may have been invented by (1) plastering gourds or coco-nuts with clay to resist the fire when boiling water in them; (2) observing the effect of fire on the clay; (3) leaving out the vegetable part.12 This must have been a comparatively recent discovery; though there is some evidence of pottery having been made by palæolithic man. It is impossible to say when fire was discovered; but it was certainly known to the Mousterian culture—say, 50,000 years ago: probably very much earlier; and it was made by hunters.