That the human species as we now see it, with its several races, Mongolian, Negro, Mediterranean, etc., represents a Family of the Primates is generally agreed; and there is evidence that the Family formerly comprised other species that have become extinct. Our nearest surviving zoological relatives are the Gorilla, Chimpanzee and Orang, and (at a further remove) the Siamang and Gibbons; and in spite of the fundamental anatomical resemblance between those apes and ourselves, the difference is so great that some explanation of how it came about is very desirable.

The differences between Man and his nearest relatives are innumerable; but taking the chief of them, and assuming that the minor details are correlated with these, it is the hypothesis of this essay that they may all be traced to the influence of one variation operating amongst the original anthropoid conditions. That variation was the adoption of a flesh-diet and the habits of a hunter in order to obtain it. Without the adoption of a flesh-diet there could have been no hunting; but a flesh-diet obtained without hunting (supposing it possible) could have done nothing for the evolution of our stock. The adoption of the hunting-life, therefore, is the essential variation upon which everything else depends. We need not suppose that a whole ancestral species varied in this way: it is enough that a few, or even one, of the common anthropoid stock should have done so, and that the variation was advantageous and was inherited.

Such a variation must have occurred at some time, since Man is everywhere more or less carnivorous; the earliest known men were hunters; weapons are among the earliest known artefacts. And it is not improbable that the change began at the anthropoid level; because although extant anthropoids are mainly frugivorous, yet they occasionally eat birds’-eggs and young birds; the gorilla has been said to eat small mammals; and other Primates (cebidÆ, macaques and baboons) eat insects, arachnids, crabs, worms, frogs, lizards, birds; and the crab-eating macaque collects a large portion of its food on the Malay littoral. Why, then, should not one ape have betaken itself to hunting?

We need not suppose that our ancestors were ever exclusively carnivorous: that is very unlikely. A mixed diet is the rule even amongst hunting tribes, and everywhere the women collect and consume fruits and roots. But if at first nearly omnivorous, our ancestor (it is assumed) soon preferred to attack mammals, and advanced at a remote date to the killing of the biggest game found in his habitat. Everywhere savage hunters do so now: the little Semang kills the tiger, rhinoceros, elephant and buffalo; and many thousands of years ago, in Europe men slew the reindeer and the mammoth, the horse and the bison, the hyÆna and the cave-bear. It is true they had weapons and snares, whilst the first hunter had only hands and teeth.

The change from a fruit-eating to a hunting life subserved the great utility of opening fresh supplies of food; and, possibly, a failure of the normal supply of the old customary food was the direct cause of the new habit. If our ape lived near the northern limits of the tropical forest, and a fall of temperature there took place, such as to reduce (especially in winter) the yield of fruit and other nutritious vegetation on which he had subsisted, famine may have driven him to attack other animals;[1] whilst more southerly anthropoids, not suffering from the change of climate, continued in their ancient manner of life. A large anthropoid (Dryopithecus) inhabited Central Europe in the Miocene, for his bones have been found; there may have been others; and during that period the climate altered from sub-tropical to temperate, with corresponding changes in fauna and flora. Hence it formerly occurred to me that perhaps the decisive change in the life of our Family happened there and then. It seems, however, that good judges put the probable date of the great differentiation much earlier, in the Oligocene;[2] and since I cannot find that any extensive alteration of climate is known to have happened during that period, it seems necessary to fall back upon “spontaneous” variation (as one must in many other cases); that is to say, from causes which are at present beyond our vision, the fateful ape did, in fact, prefer animal food so decidedly as to begin a-hunting for it. That being granted, the rest of the history was inevitable. The new pursuit was of a nature to engross the animal’s whole attention and co-ordinate all his faculties; and to maintain and reinforce it, his structure in body and mind may reasonably be supposed to have undergone rapid modification by natural selection; because those individuals that were in any organ or faculty best adapted to the new life had an advantage, which was inherited and gradually intensified.[3]

§ 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 onomatopoeia, 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.

§ 3. Minor and Secondary Consequences

(1) The extensive adoption by Man of a flesh-diet many hundreds of thousands of years ago might be expected to have shortened his alimentary canal in comparison with that of the anthropoids; but not much evidence of it is obtainable. Topinard, giving a proportionate estimate, says that in Man it is about six times the length of the body, in the gibbon about eight times. Dr. Arthur Keith, in a private communication with which he has favoured me, says that the adult chimpanzee’s intestine is slightly longer than the adult man’s, but that the measurements are for certain reasons unsatisfactory, and that there have not been enough measurements of adult chimpanzees. We must remember that, on the one hand, the chimpanzee is not exclusively frugivorous, and that, on the other hand, it is not likely that Man has been at any time exclusively carnivorous; though the return of large populations to a vegetarian diet by means of agriculture is recent.

(2) Man has lost the restraint of seasonal marriage, common to the anthropoids with other animals, as determined by food-supply and other conditions of infantile welfare; though, according to Prof. Westermarck, traces of it may still be found in a few tribes.[13] That our domestic carnivores have also lost this wholesome restraint on passion and population points, probably, to some condition of a steadier food-supply as determining or permitting the change amongst ourselves. No growth of prudence, however, or habit of laying up stores can explain the steadier supply of food; since the lower savages have no prudence and no stores. On the whole, the change may be attributed (a) to an omnivorous habit being more steadily gratified than one entirely frugivorous or carnivorous; (b) to our ancestors having wandered in quest of game from country to country in which the seasons varied, so that the original correspondence of birth-time with favourable conditions of welfare was thrown out. There may also have been causes that kept down the normal numbers of the pack, so as to be equivalent, in scarce seasons, to more abundant food: the hunter’s life, whilst securing a richer normal diet, involved many destructive incidents. And this (by the way) was favourable to rapid selection and adaptation; though if the destruction had been great enough to counterbalance the advantages of animal food, it must have frustrated the whole experiment.

(3) There is one characteristic difference of Man from the anthropoids which his hunting habits do not clearly explain—his relatively naked skin. Darwin attributed this condition to sexual selection.[14] He argued that, on the one hand, so far as Man has had the power of choice, women have been chosen for their beauty; and that, on the other hand, women have had more power of selection, even in the savage state, than is usually supposed, and “would generally choose not merely the handsomest men, according to their standard of taste, but those who were at the same time best able to defend and support them.” Hence, if a partial loss of hair was esteemed ornamental by our ape-like progenitors, sexual selection, operating age after age, might result in relative nakedness. “The faces of several species of monkey and large surfaces at the posterior end of the body have been denuded of hair; and this we may safely attribute to sexual selection.” The beard of the male, and the great length of the hair of the head in some races, especially seem due to this cause. The greater hairiness of Europeans, compared with other races, may be a case of reversion to remote ancestral conditions. But as all races are nearly naked, the common character was probably acquired before the several races had diverged from the common stock.

The species of monkey that have lost the hair on various parts of their bodies, and the beard of males (together with the longer head-hair of women) of our own race are cases that strongly support the ascription of such secondary sexual characters to sexual selection. Yet, going back to the time before the division of modern Man into races (say, 600,000 years), it seems incredible that any women then went unmarried, hair or no hair, if they were healthy (and the unhealthy soon ceased to exist); or that any man went unmarried, if he could do his share in the hunting-field (and, if not, he also soon ceased to exist). No facts observed amongst extant savages—the choice exerted by women, or the polygamy of chiefs—throw much light upon that ancient state of affairs. There were then no chiefs: the hunt-leader of pack or clan had no authority but his personal prowess, no tradition of ancestry or religion, nor probably the prestige of magic, to give him command of women. Unless, at that time, relative nakedness was strongly correlated with personal prowess in the male and efficiency in the female, it is difficult to understand how it can have been preserved and increased by sexual selection. Forgive me for adding an unkind remark: if the selection of women for their beauty has gone on for hundreds of thousands of years, and has had a cumulative effect upon the race, is not the result disappointing? Go into the street and look. That “women have become more beautiful, according to the general opinion, than men,” is not an objective, truly Æsthetic judgment, but one determined by causes of which “general opinion” is falsely unconscious. Schopenhauer[15] thought that men are better looking than women; and of average specimens this seems to be true; though, to be sure, he was a sort of misogynist.

Another explanation of Man’s nakedness was suggested by Thomas Belt, based on the parallel case of certain races of naked dogs, namely, that he is the better able to free himself from parasites.[16] Darwin mentions this hypothesis and, in a footnote, cites in its favour “a practice with the Australians, when the vermin get troublesome, to singe themselves”; but he says, in the text, “whether this evil is of sufficient magnitude to have led to the denudation of the body through natural selection, may be doubted, since none of the many quadrupeds inhabiting the tropics have, as far as I know, acquired any specialised means of relief.”[17] It appears, too, that against the probability of such a result must be set the actual disadvantage of nakedness, as insisted upon by Wallace, who says that savages feel the want of protection and try to cover their backs and shoulders.[18] Still, the disadvantage implied in occasionally feeling the want of protection would not prevent the loss of hair, if this would deliver the race from serious dangers from vermin; and the force of the argument from the condition of other tropical quadrupeds depends, at least in some measure, upon whether or not there is something peculiar in the case of naked dogs and men.

Belt argues that the naked dogs with dark, shining skins, found in Central America and also in Peru,[19] and which were found there at the Spanish conquest, have probably acquired their peculiar condition by natural selection, because they are despised by the natives, and no care is taken of their breeding, and yet they do not interbreed with the common hairy varieties, as usually happens with artificial stocks. The advantage of a naked skin being the greater freedom it gives from ticks, lice and other vermin, the advantage is especially great for a domestic animal living in the huts of savages, where, because they are inhabited year after year, vermin are extraordinarily abundant. The naked dog, then, differs from tropical quadrupeds which are adapted from a dateless antiquity to such vermin as infest them, by having been thrown by human companionship amongst not only strange vermin, but vermin in extraordinarily dense aggregation. Belt would have guarded a weak point in his case, had he explained why naked races of dogs are so scarce. Hairy races may have been more recently domesticated, or bred for their hairiness, or less addicted to an indoor life.

The case of our own forefather also differs somewhat from that of other tropical mammalia; because, by hypothesis, he underwent pretty rapidly such an extraordinary change of life; which may have brought him into circumstances where vermin, formerly negligible, became highly injurious. “Monkeys,” as Belt observes, “change their sleeping-places almost daily”; the Orang is said to construct a fresh nest every night; this is also reported of the Gorilla. Not improbably, then, daily change of locality was the practice of the original anthropoid stock, whence we also are descended: thereby avoiding the accumulation of vermin. Did the hunting life introduce a new habit? In the old frugivorous forest life, the custom was to get up into some tree for the night, and within a short radius there were hundreds equally suitable; and, therefore, there was nothing to check the natural preference for a fresh one. When, however, the hunting pack began to make its lair on the ground, there was no such wide choice amongst caves, rock-shelters, or thickets: one might be better than any other for miles around. If, then, they settled down there as in a common lair, the circumstances were, for the time, favourable to the multiplication of vermin, and therefore to nakedness of skin, in order the more easily to be rid of them. Perhaps, then, this difference of Man from the anthropoids may be referred to one common cause with all the others—the hunting life. There, too, the defilement of blood made fur inconvenient to animals not apt to cleanse themselves, like those in the true carnivorous heredity and tradition.

When we consider how injurious some insects are to vertebrate life, being suspected of having caused in some cases the extinction of species, can it be said that facility in ridding oneself of such vermin as lice and ticks is an inadequate cause of human nakedness, or not one that might outweigh the drawbacks of cold and wet? It is not, however, incompatible with the action of sexual selection, tending to the same result; nor, again, with the preferential destruction of hairy children if ever infanticide was practised. A further possible ground of deliberate selection may have been the mere ambition of differing from other animals; for a tribe on the Upper Amazons is reported to depilate to distinguish themselves from the monkeys, and the wish to be superior to other animals led a tribe in Queensland to pretend that they, unlike kangaroos, etc., have no fathers according to the flesh.[20] Admitting that this last motive can hardly have been primitive, still, our nakedness may be a resultant of several causes.

(4) Cannibalism, where it has been found amongst extant peoples, or is known to have been formerly practised, was often justified by certain magical or animistic ideas, but sometimes frankly by dietetic taste, or by the satisfaction of revenge or of emphatic triumph over an enemy. Was it an ancient and perhaps general custom? The excavations at Krapina in Croatia disclosed along with remains of the Neanderthal species, which seems to have had a habitation there, those of rhinoceros and cave-bear and of some other kind of Man; and “some of the human bones had been apparently split open: on that slender basis the Krapina men have been suspected of cannibalism.”[21] If the suspicion is valid, the practice existed (say) 50,000 years ago in one species of Man; and perhaps much earlier, if we consider how it was merely an extension of the practice of devouring game to include the slain members of a hostile pack; for as primitive Man, or Lycopithecus, his pre-human forebear, no doubt regarded other animals as upon the same level as himself, so he will have regarded human enemies as upon the same footing with other animals. That true carnivores are not generally cannibals may be put down to their more ancient and perfect adaptation to a predatory life. For them persistent cannibalism would have been too destructive, and for us it belongs to the experimental stage of history; though, of course, even in recent times, under stress of famine, reversion to the practice is not unknown to civilised men.

(5) The extraordinary variability of modern Man (considered as one species) in stature, shape of skull, size and power of brain, colour, hairiness, quality of hair, and other characters, physical and mental, may be referred chiefly to his having become adapted to various local conditions upon settling here or there for long periods of time after wandering over the world in quest of game. The settling of offshoots of the original stock in certain regions long enough for them to undergo adaptation to local circumstances is the simplest explanation of existing races: the Negro adapted to equatorial Africa; the Asiatic stock (“Mongolian”) to Central Asia; the Mediterranean race to the neighbourhood of the sea after which it is named. As to the Nordic sub-race (of the Mediterranean, we may suppose), with its fair hair and skin, it has the appearance of an Arctic beast of prey, like the Polar bear. The snow-leopard of the Himalaya is found at a midway stage of such adaptation. Some geologists and zoologists now believe that, during the Glacial Period, the climate of Northern Europe was not everywhere such as necessarily to destroy the local fauna and flora, and in that case our ancestors may for ages have maintained themselves there; or, if that was impossible (as the absence of palÆolithic remains in Scandinavia seems to indicate), they may have roamed for many ages along the borders of glaciation, perhaps as far as the Pacific Coast. Chinese annals refer to fair tribes in Eastern Siberia 200 years before the Christian era;[22] and it seems requisite to imagine some extensive reservoir of mankind in order to explain the origin of the vast hordes which in prehistoric as in historical times again and again invaded Europe—hordes

That the race was formerly fairer than it is now may be inferred from the whiteness of its children’s hair: the trait has outlived its utility. The occurrence of a fair complexion in some mountain tribes, in the Alps, e.g., has occasioned the conjecture that it may be due in some way to mountainous conditions,[23] of which snow might be one; but, if we suppose that the Nordic race extended during the Glacial Period into Western Europe (having already acquired its distinctive characters), a fair complexion in the Alps may be understood by supposing that, whilst the greater number of them followed the ice-sheet back to the north-east, some followed it southward up into the mountains—if the complexion is really ancient there.

Two objections to this hypothesis will occur to every one: (i) Why are not the Esquimo fair? Because, I suppose, they are much more recent immigrants into the Arctic regions, and perhaps were fully clothed when they arrived there. (ii) Could the Nordic people have existed in such circumstances unclothed? Whether this was possible physiologists must judge. We see the Fuegians maintain themselves, practically naked, under very inclement conditions. And it is not necessary to assume that the Nordic hunters were entirely naked; since the correlation between the hair, eyes and all parts of the skin is such that, if the whitening of any part (say the hair) was sufficiently advantageous to determine natural selection, the remainder of the body would be similarly affected. And, no doubt, the Mediterranean race was always whitish.

The Amerinds seem to have been derived chiefly from the Asiatic race. Pygmies and Australians may represent separate and still older stocks. But, as a result of migrations and conquests, most peoples are of mixed descent; and hence (i) individuals in the same locality sometimes vary greatly, because they inherit the blood of different strains in different proportions; and (ii) classification is difficult, so that whilst some observers are content to find half a dozen races, Deniker enumerates twenty-nine.

Besides general racial differences, there exist within each race and within each national group further differences between individuals in their physical, and still more in their mental, stature and ability. As it was necessary that Man should vary greatly in undergoing adaptation to the hunting life (as well as to different local environments), he was in an organic condition favourable to further variation.[24] And this has been utilised in his adaptation to a certain special condition of his gregariousness, namely, life in the hunting-pack; for this requires a difference of personality between leaders and followers, first in the chase and later in war. A good democrat may think it would have been a better plan to make all men equal from the first; and I would it had been so; for then the head of the race would not have had to drag along such an altogether disproportionate tail: a tail so huge and unwieldy that one may doubt whether it can ever be extricated from the morass of barbarism. But in the early days of gregariousness, a pack could not have held together, or have hunted efficiently, if all had been equal and each had exercised the right of private judgment. So in successful packs one led and the rest followed; as they still do, and will continue to do, of whatever kind may be the leader. And of all structures that make up a human being the most variable is the brain: the differences between men in stature and physique are trifling compared with those in mental power. Whatever feat of strength your Samson can perform, half a dozen ordinary men can also accomplish; but in every generation tasks are carried out by intellectual athletes, toward which all the ordinary men in the world, uniting their efforts, could do nothing—absolutely nothing.

§ 4. Prey and Competitors

If we suppose the differentiation of the HominidÆ from the Anthropoidea to have begun in the Upper Oligocene, and that the decisive change was initiated by some ape that adopted the life of a hunter, it is interesting to consider what the world was like in which he lived, what sort of animals surrounded him, what animals probably became his prey, and what were his rivals in the chase.[25]

The surface of the planet was less mountainous than at present; in Europe the Pyrenees had risen, but the Alps were only beginning to rise; and in Asia the Himalayas began to dominate the world only in the middle of the next epoch, the Miocene. The distribution of land and water, too, was very different in the Oligocene from that which we now see: Europe was divided from Asia by a broad gulf stretching from the Indian Ocean to the Arctic Circle, and an arm of this gulf toward the west submerged a great part of Central Europe; Asia was broadly connected with North America, where now the sea penetrates between Siberia and Alaska; Africa had no connection with either Europe or Asia; North and South America were separated—perhaps at Panama. In the Miocene, Europe, Asia and Africa became united. These physiographic changes may have affected climate; for during the Eocene tropical conditions prevailed far to the north, and coal-beds were laid down in Alaska; but from the Oligocene onwards there was a gradual fall of temperature, slow at first, but ending (for the present) in the cataclysms of the Glacial Period. There was also a decrease in some regions of atmospheric moisture, which determines the density of vegetation. In its general character the vegetation was similar to that which now prevails in tropical, subtropical and temperate regions of the world. The species of plants now existing had not yet arrived; but of the same genera and families as those we see, conifers, palms and dicotyledonous flowering plants crowded the forests and overhung the rivers. The forests were more extensive and continuous than ours outside the tropics; for by degrees browsing animals, feeding down the young trees, check the renovation of forests and clear open spaces, where grasses grow; changes of temperature limit the northern or southern extension of certain kinds of plants, and a failure of humidity starves all the larger kinds; converting, at successive stages, forest into steppe and steppe into desert.

Animals, especially mammalia, with which chiefly we are concerned, were, at the close of the Oligocene, very different from any that now roam the lands; all the species, most genera, many families and some whole orders have since disappeared. But there were plenty to eat and a good many to dread. Until we know the neighbourhood in which our ape’s adventures began, nothing precise can be said of his circumstances. Probably it was somewhere in the Old World, and probably it was in Asia. Unfortunately, we know nothing of the zoological antiquities of Asia until the early Miocene, and even then a very small selection of what must have existed, because geologists have hitherto explored a very small part of the continent—a few beds in north-western and northern India and in Burmah. But there is so much evidence of the migrations of animals in successive ages of the Tertiary Period, that any remains from the Oligocene and Miocene will help us to understand what sort of neighbours our remote ancestors had to live amongst.

For prey there was great variety of birds and reptiles (everywhere eaten by savages) and fishes; but we are most concerned with the mammalia, which he may be supposed to have pursued afoot. Of these the most important are the hoofed animals, which fall into two great groups, perhaps not closely connected—the odd-toed (Perissodactyls) and the even-toed (Artiodactyls). During the Oligocene there lived in Europe, or in North America, or in both—and, therefore, probably in Asia—numbers of the odd-toed group: tapirs; rhinoceroses of several species, some without horns, some with, some amphibious (Amynodonts), all smaller than their modern representatives; chalicotheres, strange beasts something like horses, but instead of hoofs they had claws on their toes—perhaps survived in China into the Pleistocene; small predecessors of the horse with three toes on each foot; titanotheres, hugest animals of their age, extinct in the middle of it—something like the rhinoceros and nearly as big as an elephant (Brontotherium). Of the even-toed group, pig-like animals abounded, and some true pigs appeared; entelodonts, or giant-pigs, were common; anthracotheres, somewhat pig-like in size and shape; ancestral camels about the size of sheep were to be had in North America; oreodonts, unfinished-looking creatures of many species; primitive deer and other ruminants, small in size and not having yet grown any horns. In Europe, during the Upper Oligocene, coenotheres, small and graceful animals, lived in large herds around the lakes. There were also primitive proboscidia about half the size of modern elephants; many insectivores; and, amongst rodents, beavers and tailless hares. Generally, animals of this age that have left descendants were smaller than their modern representatives; and notably their brains were smaller.

In the Lower and Middle Miocene there appeared also horned cervuline deer, chevrotaines, and horned antelopes; dinotheres and mastodons, probably from Africa; primitive hedgehogs, moles and shrews; and in the Upper Miocene, hipparion, true hares, several varieties of hornless giraffe, true deer, and ancestral sheep. True horses and cattle are first known from Pliocene beds; but it is needless to follow the story further: the fauna becomes more and more modern in its character, and uncouth forms die out.

Anthropoids are first met with in the Miocene and in Europe: pliopithecus, allied to the gibbons, in the Lower; and dryopithecus, related to the chimpanzee, in the Middle Miocene; but they are believed to have come from Asia. There, in Pliocene beds of the Siwaliks (southern foot-hills of the Himalayas), occur the orang and chimpanzee, besides macaques, langurs and baboons. Since the orang is now found only in Borneo and Sumatra, and the chimpanzee only in Africa, southern Asia seems to have been the centre from which the anthropoids dispersed; and this seems to be the chief positive ground for believing that the human stock began to be differentiated in that region. Since, again, by the Middle Miocene a chimpanzee form had already migrated into Europe, it may be assumed that the orang was already distinct from it (and perhaps had spread eastward): the differentiation of these genera must, therefore, have happened earlier; and, therefore, also the differentiation of the human stock; so that this event cannot be put later than some time in the Oligocene.

How big was Lycopithecus to begin with? The answer to this question must affect our view of his relations both to prey and to enemies. Inasmuch as the three extant anthropoids and Man are all of about the same size, there is a presumption that their common ancestor was in stature superior to the gibbons and to the largest monkeys—in fact, a “giant” ape (to borrow a term from Dr. Keith). Dryopithecus “was smaller than the chimpanzee, but much larger than the gibbon.”[26] Awaiting further evidence of fossils, which is much to be desired, it is probable, on the whole, that Lycopithecus weighed less on the average than modern man, but more than the wolf.

As to competitors and aggressive enemies, there were snakes and crocodiles; but, confining our attention to carnivorous mammals, the time seems to have been favourable to the enterprise of a new hunter. By the middle of the Oligocene, the ancient Creodonts (primitive flesh-eaters which had flourished in the Eocene) were nearly extinct, represented in the deposits by their last surviving family, the Hyoenodonts. Ancestors of the modern carnivores, such as may be called by anticipation dogs and cats, derived (according to Prof. Scott) from the Creodont Family of the MiacidÆ, were becoming numerous, but for the most part were still of small size. Apparently, the primitive dogs and their allies must, for some time, have been more formidable adversaries than the primitive cats, especially if we suppose them to have already begun to hunt in pack; and this is not improbable, both on account of their structure and because several distinct varieties and even genera, now extant, have that habit—such as wolf, jackal, dingo, dhole, Cape hunting-dog, etc. In the Upper Oligocene of North America, occurs a dog as big as a large modern wolf, and in Europe the bear-like dog, Amphicyon, of about the same size, but said to have been clumsy and slow-moving. There were several other dog-like species; they continue in the Miocene, and some of them increase in bulk; but true modern dogs or wolves (Canis) do not appear before the Pliocene. Then, too, first occur true bears (Ursus); hyÆnas in the Upper Miocene. “Cats” belong to two sub-families: (i) the true felines, our modern species and their ancestors; and (ii) the machÆrodonts, or sabre-toothed cats. The latter first appear in North America in the Lower Oligocene; the former in Europe in the Middle Oligocene. The sabre-tooths are so called from their thin, curved upper canines; which were so long (3 to 6 inches) that it is not easy to understand how they could open their mouths wide enough to bite with them. That they were effective in some way is proved by the fact that machÆrodonts, first appearing in the Lower Oligocene, increased in numbers and diversity of species for ages, and some of them in bulk. In North America, in the Upper Oligocene, one species was as large as a jaguar, and some of the biggest and most terrifying were contemporary with Man, and only became extinct in the Pleistocene. Their limbs were relatively shorter and thicker than those of the FelinÆ. These, the true cats, at first progressed more slowly than the MachÆrodontidÆ; but in the Siwalik deposits (Pliocene) there occur, along with machÆrodonts, forms resembling the leopard and the lynx, with others as large as tigers. The largest of all this group seems to have been the cave-lion, perhaps a large variety of the common African lion, which also lived with Man in Europe in the Pleistocene. These were serious competitors in the hunting-life of Lycopithecus and of primitive Man; and the effect of such competition in exterminating inferior forms is shown by the fate of the carnivorous marsupials of South America (allied to Thylacinus), which were the predatory fauna of that region, until in the Pliocene, North and South America having become united by continuous land, cats and dogs came in from the northern continent and put an end to them; and also by the fate of the creodonts, which in the Oligocene seem everywhere to have been exterminated by the new carnivores. In both cases the beaten competitors were very inferior in the size and complexity of their brains; and if Man has succeeded in the struggle for life against the same foes, in spite of his inferior bodily adaptation, it is probably due to his very superior brains. This may also be the reason why modern Man (Homo sapiens!), wandering everywhere over the world, has everywhere exterminated such experiments in human nature as Pithecanthropus, Eoanthropus, and Neanderthalensis; as others are soon to follow them into the Hades of extinct species.

These few pages give a ridiculously faint sketch of the animal world amidst which our remote ancestors began their career. But it may serve to indicate that there was always plenty to eat if you could kill it, and plenty of rivals who wanted their share. After the disappearance of the dinosaurs at the close of the Cretaceous period, the mammalia, already numerous, developed rapidly, and spread in ever multiplying numbers and diverging shapes over the whole area of the land. We may take it that from the Middle Eocene (at least) onwards the earth has always been as full of wild beasts as it would hold. To understand what it was like in the Middle Oligocene, one should read the adventures of hunters in South Africa seventy or eighty years ago (their verisimilitude is vouched for by Livingstone),[27] before a gun in the hands of every Kaffir had begun to thin the vast herds that then covered the whole landscape, and in whose numbers the wild hunters and the lions could make no appreciable diminution. The little Bushmen regarded themselves and the lions as joint owners and masters of all the game. The masters fought one another, indeed; but there was no necessity to fight, for there was more than enough for both: lions were then sometimes met in gangs of ten or a dozen. Game throughout the Cainozoic ages was abundant and of all sizes: many small, many middle-sized and some prodigious. Even in the Eocene, some of the Amblypoda (Dinoceras, Am.) and of the Barypoda (Arsinotherium, Af.) were as big as rhinoceroses; in the Oligocene, Titanotheres not much smaller than elephants; in South America, in Miocene and Pliocene times, the Toxodonts; in the Pleistocene, Ground-sloths of huge bulk, and Glyptodonts. Of Families still represented amongst living animals, dinotheres and mastodons occur in the Miocene; and elephant, rhinoceros, hippopotamus, giraffe have abounded from the Pliocene to recent times, in many species, over most of Africa and the northern hemisphere. Even the marsupials in Australia produced a species (Diprotodon) as large as a rhinoceros with a skull three feet long. Any one of these would have been a meal for a whole pack of hunters, if they could kill it—as we may be sure they could.

§ 5. Conclusion

From the addiction of some ancestral ape to animal food, and to the life of a hunter in order to obtain it, then, the special characteristics of Man seem to be natural consequences. The hypothesis from which everything follows is exceptionally simple and moderate. It is generally admitted that our ancestor was a large anthropoid—possibly more gregarious than others, possibly more apt to live upon the ground; but neither of these suppositions is requisite. He was adapted to his life, as the chimpanzee and gorilla are to theirs: in which, probably, they have gone on with little change for ages. But into his life a disturbing factor entered—the impulse to attack, hunt and eat animals, which extensively replaced his former peaceable, frugivorous habit. The cause of this change may have been a failure in the supply of his usual diet, or an “accidental variation” of appetite. Not a great number need have shared in the hunting impulse; it is enough that a few should have felt it, or even one. If advantageous and inheritable, it would spread through his descendants. It was advantageous (a) in enlarging their resources of nutrition, and (b) in enabling them to escape from the tropical forest. On the other hand, to those least fit for the new life it brought the disadvantages of more strenuous exertion and of competition with other carnivorous types. But with hands and superior intelligence, those that had the requisite character succeeded. There was rapid selection of those whose variations of structure, character, activity were most effective in dealing with game and with enemies; especially of those who combined and co-operated, and learned to direct co-operation by some rudimentary speech.

But, again, the hunting impulse here assumed to have possessed some anthropoid was not something entirely new; anthropoids and many other Primates are known to seize and devour birds, lizards and even small mammals when chance offers an easy opportunity. It is merely a greater persistence in this behaviour that turns it into hunting. How very improbable that such a change should not sometimes occur! Is it not likely to have occurred often, and with many failures? Similarly, of the resulting changes: the differentiation of our hands and feet is only an advance upon what you see in the gorilla; as for our ground-life, can the adult male gorilla be fairly called arboreal? Several Primates use unwrought weapons; most of them lead a gregarious life, to which our own is a return; they are co-operative at least in defence; like many other animals, they communicate by gestures and inarticulate vocal cries. Co-operative hunting, indeed, seems to be new in our Order; but since wolves and dogs, or their ancestors, fell in with it some time or other, why should it be beyond the capacity of apes? On second thoughts, is the co-operative raiding of plantations by baboons something altogether different from hunting in pack? Thus at each occasion of change in structure or function, Lycopithecus merely carried some tendency of the other Primates a little further, and a little further; until, certainly, he went a long way. The whole movement can be distinctly pictured throughout, and it has an air of being natural or even inevitable. Few hypotheses ask us to grant less than this one.

Moreover, if the story is not true, Man is an exception to the rule of animal life, that the structure of every organism is made up of apparatus subserving its peculiar conditions of nutrition and reproduction. Indeed, conditions of nutrition are the ground of the differentiation of animals and plants. Conditions of reproduction need not here be considered, as the apparatus is the same in the anthropoids and in ourselves. With many species to avoid being eaten and to mate are the reasons for some secondary characters, such as protective armour or coloration, fleetness with its correlative structures, nuptial plumage, and so forth. But to avoid being eaten and to mate, it is first of all necessary to eat and live; and accordingly, for each sort of animal, starting from the organisation of some earlier stock, its structure and activities are determined by the kind of food it gets, and the conditions of getting it: in our case, the hunting of game afoot.