The Bipeds

I

It was once thought that "man is the only toolmaker". This was believed partly because only members of the genus Homo are known to have made artifacts from stone - and stone artifacts are the only prehistoric artifacts which usually remain to tell the story. It is now known that some animals do make tools; and chimpanzees - our nearest living relatives - make quite a lot of simple tools out of perishable natural materials.

Bipedality obviously made toolmaking and tool use easier, because it set the forelimbs free from other duties, so that (among other things) bipedal primates could develop new powers of manipulation and learn to process difficult but useful materials like stone. But the first bipedal apes, now called australopithecines, lived and flourished for several million years and yet (it seems) never learned to make anything out of stone at all. They probably made many tools from perishable materials - we may never know much about those. But apart from tool-making, there was also another reason why the upright posture helped them to survive.

There was a change in their canine teeth. Other primates (including chimpanzees) have long and dangerous canines. In some of the earliest australopithecine fossils, the canines are still bigger than the other teeth, though smaller and less impressive than those of a chimpanzee. In the later australopithecine fossils, the canines take their place, as ours do, as food-processing tools rather than weapons. The picture below, taken from Glenn Conroy's Reconstructing Human Origins, shows (left) the teeth of Proconsul, an earlier fossil ape, (centre) the teeth of Australopithecus afarensis (about 3.3 million years ago) and (right) Australopithecus africanus (about 2.6 mya):

Canine teeth are an essential piece of equipment to an ape (as to monkeys and many other animals). Apes have no horns, claws or hooves: the canines are their principal weapons. Canines are used to fight against, and to deter, predators and rival members of their own species. Occasionally they are used to kill animal prey. If bipedality enabled the australopithecines to manage without these essential weapons, it must have provided them with an alternative weapons system, or they would not have survived.

Chimpanzees do not rely entirely upon their teeth when fighting. Michael Leach, an acute and experienced observer in the wild, tells us that when two rival groups meet..

..bloody warfare can break out. When one group greatly outnumbers another, chimps will fight in small cooperative packs; two or three animals will hold down an enemy while the others bite and hit him...Armed with piercingly long canine teeth and flesh-crunching molars, a chimpanzee bite can inflict terrible damage on an opponent. On top of this, they are fast, strong and extremely aggressive. They will attack enemies, of any species, with long branches wielded as clubs, together with missiles carefully selected for their weight. Experienced males go out of their way to collect large stones in preference to pebbles...The same firepower is turned on any carnivore that comes too close.

(Michael Leach The Great Apes)

Other sources confirm that chimpanzees often throw sticks and stones, but tend to suggest that they are not very good at it. The forelimbs of a chimpanzee are general purpose organs, adapted for locomotion - and needed for locomotion whenever the animal wants to move quickly and nimbly. A habitual quadruped is likely to be slow and liable to lose its balance when fighting on the back legs alone.

But the australopithecines, although related to chimpanzees, were fully adapted bipeds, probably as quick on their two feet as an active modern man. They had hands and arms which (not being required for locomotion) could afford to specialise in manipulation - throwing and handling weapons and natural tools. They must have become much better at throwing stones; they would have been better able to carry a supply of stones around with them, and they would have been better at fighting at close quarters with natural clubs. As bipeds, able to keep predators at a safe distance much of the time with missiles and clubs, they had less and less need to bite or threaten their enemies with their teeth. It was more useful for the canines to be adapted for eating.

The natural connection between bipedality and the loss of canine weapons was suggested long before the first australopithecine remains were discovered, by no less than Darwin:

The free use of the arms and hands, partly the cause and partly the result of man's erect position, appears to have led in an indirect manner to other modifications of structure. 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 less and less.

(Darwin: The Descent of Man)

Nevertheless the importance of throwing and the use of other natural weapons has not always been registered. In the words of a brilliant paper by Barbara Isaac (see link):

Ability to throw was probably achieved at an early stage of human evolution but has received little scholarly attention. Although this ability is poorly developed in apes, anatomical studies suggest that the hand of Australopithecus afarensis was adapted to throw with precision and force.

Mrs Isaac's paper pointed out nearly twenty years ago that

A cornered band of protohominids armed with rocks weighing 200g would be formidable opponents. All carnivores avoid disablement which can lead to starvation....the use of stones would usually be defensive, occasionally aggressive, and subsequently predatory.

There is no evidence that australopithecines made artificial stone weapons - though (like chimpanzees) they must surely have made some simple tools (see link) out of perishable materials. The appearance of Homo - the next stage in bipedal development - coincides with the first stone artifacts. But the ability to throw stones (and to carry around with them a stock of suitable natural ammunition) must have given all these bipeds something which no other animal had - the ability to defend themselves and their young by inflicting injury at a distance whilst remaining out of range of their enemies' teeth and claws.

The throwing action is a complex one, in which great power and accuracy are achieved by the coordination of all the muscles of the arm, wrist, fingers and back - even of the legs. If, as it seems, the ability to throw missiles effectively was a fundamental factor in bipedal survival, then the evolution of those muscles (and of the brain which controlled them) must have been influenced by the need to develop that ability. Bipeds are perhaps (among many other things) animals evolutionarily designed to survive by throwing missiles.

The evidence suggests that the long struggle for bipedal survival and ultimately human dominance over all other species began when the australopithecines differentiated themselves as animals which walked, ran and fought on their back legs only, and could use their forelimbs to wield weapons and to throw missiles, thus uniquely becoming able to drive away predators and competitors whilst avoiding combat at close quarters. That may be how they survived. For we have to remember that until quite recently, the environment in which bipeds have lived was always a very dangerous one; and the first question we have to answer is how they survived in it at all.

II

The relationship of the early bipeds to their living environment is hard for us to imagine. Nowadays few wild animals are dangerous to us in practice because almost all of them avoid us at all costs. We are so accustomed to their respect for us that we have forgotten that at some time in the distant past, the big cats, hyenas and jackals must surely have regarded bipedal primates - particularly, of course, their defenceless young - as a natural prey. Lions and leopards, cheetahs, sabretooths, jackals and hyenas - and eagles, well able to carry off a biped infant - was there any reason why they should have not have preyed upon australopithecines and early hominids?

We live in a world where even the great predators fear people more than we fear them. We take our dominance over other animals for granted. But perhaps the australopithecines could not take it so easily for granted. As time went on, they and their successors must somehow have earned the dominance and respect that to us appears normal. Almost all animals - even the the great cats - now fear us; and their fear is partly or perhaps wholly at the level of instinct. These powerful animals must have acquired that instinctive fear because they increasingly needed to acquire it - because it became impossible to survive without it.

We ourselves have come to take their fear for granted and to rely upon it for our own safety. Even in Britain now, where the most dangerous wild animals are the fox and the badger, the safety of our small children depends to some degree upon the fear of man that all wild animals feel. A hungry fox is not frightened to go into the hen coop. Yet he would not go into a house and take a baby from its cot. Why not? We assume without thinking about it that no fox would dare to enter a house or (unless cornered) attack a human being, however small and defenceless. We take the respect we inspire in all other species for granted. But what is it that they so respect in us?

The answer is probably our long-range weaponry. From the time of the australopithecines, we bipeds have developed long-range weapons which have given us an increasing advantage over animals who could only fight at close quarters. Animals in the wild have learned from hundreds of thousands of years of experience of us and of our bipedal predecessors that our missiles - first stones, later spears, arrows and bullets - can kill or maim quite unexpectedly from a distance without harm to ourselves. They have learned that even to be seen, at a distance, by a biped, can be dangerous or even fatal. It is best to keep out of our way, at least during daylight. That is why we can often walk through a wood which is full of wild animals of all kinds and yet hear and see almost nothing. Modern animals have learned the need to keep out of our way and have passed the knowledge on genetically or by example to their offspring. Those who failed to learn this essential lesson have left no descendants.

From the beginning, bipeds probably became expert at throwing stones. A shower of stones can kill any animal which cannot run away (people have been executed by stoning) and well-aimed sharp stones might well drive away a leopard or a lion. Against an animal which can run away, the value of stoning is primarily defensive; but in conflict with a predator, defensive action is all that is required. Predators are careful to avoid injuries because even a minor injury can diminish their chances of killing prey and can rapidly lead to starvation.

To shape stones to make more effective projectiles was the logical next step. It may well be that the so-called handaxe was a specially sharpened stone missile - a specially made "throwing stone" just as the boomerang was a specially made "throwing stick". Over the immensely long period during which handaxes were produced - a period of more than a million years, during which the hominid brain almost doubled in size - the art of making and throwing missiles is likely to have been gradually perfected. If a hominid (with the benefit of training or example based on hundreds of thousands of years of practice) could throw a sharpened stone missile reliably to hit a distant target point first - and he probably could - it would have been a very dangerous weapon. Over the million years of handaxe development, the bipeds undoubtedly made themselves increasingly formidable opponents whom it had become dangerous for most other animals to approach too closely. But this did not mean that they were masters of their environment.

Effective though it would have been as a defensive weapon, even a well-thrown handaxe would have lacked the penetrative power necessary to kill or disable a large animal. The weapons of humans were later to make them by far the most successful of hunters. The earlier bipeds were undoubtedly able to knock down small animals and birds with stone missiles, but they would have found it much more difficult to hunt and kill large animals. Recent archaeology shows that earlier bipeds possessed nothing that would be regarded as an effective weapon by modern or even by medieval standards. To kill a large animal, a stone point needs to gain momentum and penetration by being hafted on to a wooden shaft. No such hafted spear points or arrow heads appear until around 50,000 years ago. Apart from sharpened stone missiles, what other weapons were available? Wooden clubs and sharpened wooden spears are useful defensive weapons but of limited use for hunting.

Animal food appears to have been part of the later biped diet, but this does not necessarily provide evidence of hunting large animals. If a shower of stones could drive a leopard away from an infant, it could also drive it away from an animal which it had just killed. It was probably possible to obtain big game by waiting at a water hole until a heavy animal was killed by a predator and then driving the predator off the carcase with missiles. Perhaps the bipeds were prey-stealers rather than predators.

Biped predation may already have caused the extinction of some smaller species which had turned out to be specially vulnerable to it; the great herds of hoofed mammals had probably learned to fear the bipeds, but their numbers are unlikely to have been significantly reduced; the thick-skinned members of the elephant family, the dominant animals of their time, probably had little reason to fear biped attack.

III

70,000 years ago - perhaps 3500 human generations - our picture of the past shows us a world which was still dominated by larger animals. In particular, mammoths and other members of the elephant family existed in huge numbers almost everywhere in the world. Elephant influence on the environment - still true of a few small areas of Africa - was probably once the rule elsewhere. It was a very long time before the elephant-made landscape was replaced by a man-made one. Until that happened, our predecessors lived in an environment over which they had relatively little influence.

Throughout the whole world (with the exception of Australia and the oceanic islands, where in any case there were no bipeds either) the members of the elephant family - mammoths, mastodonts and and mastodons - then lived in huge numbers. They feared few predators and had adapted to almost every kind of climate. It is not likely to have been the hominids who determined the shape of the landscape in which they lived. More probably it was the large mammals - particularly members of the elephant family:

The elephant has shaped much of the natural African landscape, rendering it more fit for habitation by human beings. ..As they forage, elephants create and maintain broad paths through impenetrable bamboo and elephant grass belts, and in forested areas, they keep extensive glades in permanent state of early succession, not only breaking down trees but also tearing up acres of saplings for their roots. They excavate and weed out water holes, and “garden” interconnected glades and clearings into tangled vegetation.

(Chapurukha Kusimba)

Elephants make tracks through forest which man and other animals subsequently use; many of our present-day roads may well have originated in this way. They dig wells which are subsequently used by other animals:

The wells that they dig can reach nearly 2m in depth. Most well-digging is initiated by adult males, which locate the best places to dig by finding damp places on the ground surface. ..Wells dug by elephants collapse after the rains begin, yet they are invariably redug within a few feet of where they had been located before..

(Gary Haynes (1991) Mammoths, Mastodonts & Elephants)

Elephants are highly intelligent animals and until the appearance of the bipeds, the only mammals which could manipulate objects without needing to to use limbs intended mainly for walking, running or climbing. The elephant trunk is immensely strong yet able to pick individual blades of grass. Elephants appear to have sophisticated means of communication over distances (using low-frequency notes which we cannot hear). Until the appearance of humans, the elephant was undoubtedly nature's masterpiece.

Mammoths were closely related to modern elephants and are likely to have behaved very similarly:

Great differences in the social behaviours of the extinct species seem unlikely; the two surviving taxa (African and Indian elephants) diverged from a common ancestry millions of years ago and yet today they display behaviors that are strikingly similar. Their behaviors might therefore be similar to to those of directly ancestral or closely related extinct forms.

(Haynes)

It is easy and probably correct to imagine woolly mammoths providing drinking water for themselves (and of course others) by breaking holes in the ice on frozen Siberian rivers and lakes.

How effective would stone missiles, clubs and wooden spears have been against a herd of mammoths? The bipeds who lived before the coming of humanity (only at most 5000 generations ago) probably always lived in fear of elephants and had little control over the environment in which they lived. Agriculture was inconceivable because crops would have been trampled and eaten. Permanent dwellings (unless in inaccessible locations) would always have been liable to be overrun.

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