A History of the World
Page 3
Eve’s tribal group was already a remarkable achievement in survival against the odds, part of a human population of several hundreds of thousands in Africa, which had emerged in competition with other varieties of clever ape. Human history, properly understood, starts when we move from being just another form of prey in the cycle of eat-and-be-eaten, a creature blown about by the natural world, to a creature beginning to shape the world. We move from happens-to, to makes-happen.
But Homo sapiens was only one branch of a tree of hominids who were learning how to alter their environment, if only in a minor way. There are almost no historical arguments as complex and heated as those about modern man’s origins. The reason is straightforward: scientific advances in the study of human DNA and in the dating of bone fragments and other material keep challenging, and sometimes overturning, earlier theories. It may be the furthest-back part of human history but it is changing faster than the history of, say, the Second World War. Amateurs must step delicately across an exciting minefield.
One thing that is now widely agreed, however, is that this is a story in which climate plays a pivotal role, more so than we used to realize. The cooling and warming of the planet because of solar activity, meteorite strikes, eruptions or tiny changes in its angle of spin affect the advance and retreat of deserts, the opening or closure of bridges for migration, and thus the story of our storytelling ape. In general, the more complicated the changes in the climate, even when they produce the extinction of other animals, the faster the advance of hominids seems to have been.
Adversity favours the versatile. The first attempts by tree-living African hominids to live on two feet came after cold, dry weather attacked their forests two million years ago. The open grasslands that resulted made it imperative to be able to run and hunt and see into the distance, and scientists believe this eventually resulted in Homo erectus, an important early version of humanity, with a brain around two-thirds the size of ours.
There were further changes in brains, as the warm Pliocene epoch gave way to the ice ages of the Pleistocene and to new challenges. Inside Africa, it now seems, a great complexity of hominids evolved. But Homo erectus, which ranged far out of Africa, evolved first into the bigger-brained Homo heidelbergensis – people who were hunting and making axes in England half a million years ago, and had a brain not so much smaller than ours, around 1,200 grams compared with our 1,500. Modern ‘us-sized brains’, had evolved in Africa around 150–100,000 years ago. This gives modern humans the largest brain for body size of any known animal, about seven times bigger than you might expect for our heft.3
This picture of human development is a brutal simplification. There are intimidating-sounding lists of pre-modern human species, varying greatly in height, shape of skull, leg bones and weight. Though scientists name and slot them into seemingly neat divisions, as evolutionary trees are assembled, the truth must have been messier. Chris Stringer of London’s Natural History Museum usefully reminds us that species ‘are, after all, humanly created approximations of reality in the natural world’.4 Skulls of similar age, which are alike but not identical, hide subtler variations between early humans lost to us, so we should not get too scared by the thicket of scientific names.
What most needs to be grasped is that modern humans were not just a single super-bright, planet-conquering ape, who leapt as if by magic from an earlier world belonging to dim ape-men. Those earlier species, including the famous Neanderthals, and in Asia the ‘Denisovans’ (both coming after Homo heidelbergensis), also survived dramatic changes in climate and pushed into new territories as pioneers, equipped with cutting- and killing-tools. They probably decorated themselves, may have had some form of language, and may even, at the edges, have interbred with the newcomers, Homo sapiens. More interesting to us, though, is what they lacked.
So let us now return to Mother and her tribal migration. Did it really happen that way? Everyone agrees that Africa retains a genetic diversity of humans not found anywhere else, and that all humans began there at some point. But there has been a major argument about whether all non-African modern humans originated in a single (or nearly single) movement out of the continent, spreading round the world from around seventy thousand years ago. The alternative idea is that these other species, which had left Africa and colonized Europe and Asia much earlier, in fact survived. Could they have evolved into, and in places also bred with, Homo sapiens?
Between the two extremes there are shades of grey, but these offer two radically different views of today’s humanity. One says that, in essence, all non-Africans are close relatives, ‘Mother’s’ children. The other argues that different human populations emerged more slowly and separately in different parts of the world. This, it is claimed, may explain why many of us look and even behave so differently. The latter view has been more popular among academics outside the Western tradition, and our ideas about contemporary humanity barely need spelling out. This is not a dry argument. Are we family, or rivals?
Scientific opinion is now heavily tilted to the ‘out of Africa’ or ‘recent African origin’ model, mainly because of advances in tracing one particular form of DNA marker, mitochondrial DNA, leading back to Africa, where modern humanity, Homo sapiens, did not begin to appear until about two hundred thousand years ago. But the old picture of apes simply getting cleverer and cleverer until ‘our lot’ walked out of Africa and began populating an empty Europe and the Middle East seems to be wrong. Just like other animals, earlier hominids had been on the march long before. Recent archaeological discoveries in South Africa suggest that fire, and cooking, were being used nearly two million years ago by Homo erectus, though this is a highly controversial issue. It would help explain the growth in brain size, since cooking greatly increases the quantity of calories that can be ingested; and brains are very energy-hungry.
At any rate, before our migration the world was already inhabited by other kinds of people. What happened to them? It is likely that they were victims of changing climate conditions, destroyed by cold and hunger when temperatures fell again, or possibly by modern humans who were better organized and able to adapt. Nor, it seems, did modern humans leave Africa through Egypt, breaking first into the Mediterranean and European worlds, as Europeans once thought. We first went south, heading down along the coast of India and South-East Asia, foraging for shellfish as we went, and eventually somehow made it to Australia across the sea. Again, scientists argue about this, but it seems possible that aboriginal Australians arrived in their land many thousands of years before aboriginal French or Spanish got to theirs. And tracing back through the DNA trail suggests that the Cro-Magnon Europeans were descended from people who, before turning north, lived in today’s India. History is the story of migration, as much as settlement, long before Columbus or the Irish arrived in America.
What caused the Homo sapiens push out of Africa? Again, there are rival theories.
Around 73,500 years ago a massive volcano erupted in what is today called Sumatra. This was by far the biggest such disaster of the past two million years,5 and some scientists suggest that modern humans nearly did not make it through at all when the eruption misted the skies and radically cooled the planet. Some argue that the human population fell back to only a few thousand individuals in southern Africa, causing a bottleneck in evolution for thousands of years. This may have produced a radical pruning-back and regrowth of a more ruthless and organized humanity, better able to migrate round the world when conditions improved – Mother’s well organized tribe. Others think this has been exaggerated and that, bad though the conditions were, many species survived them.
Once that human migration from Africa had happened, however, it is clear that further episodes of chilling and heating shaped their later movements and ultimate success. It took a long time for the routes to open up across today’s Middle East and into Europe. But once humans arrived there, a later volcanic eruption in Italy, some thirty-nine thousand years ago, and sporadic ‘Heinrich events’ �
�� when icebergs broke off into the Atlantic producing severe periods of cooling – kept the climate unpredictable. The northern ice cover retreated and then came back again several times. The migration patterns of deer, bison and other animals shifted. Comfortable refuges became grim; and then grim wastelands bloomed. Repeatedly, humans had to alter their habits and behaviour to survive. Again: adversity favours the versatile.
It seems that after the African migration, small numbers of Homo sapiens were better adapted to manage these shifts in climate than earlier versions of human had been. If so, this happened not because of classic Darwinian evolution (there wasn’t time) but because of the accelerated development caused by culture – language, learning, copying, remembering. We became more skilled with our fingers. In bigger groups, we were able to allow specialization – the best trackers to track, rope-weavers to weave, arrowhead-makers to chip. Working together we were better, more lethal, hunters. Human groups struggling to cope with a cold, drier world had to learn new things, including the ability to make more complex language, empathize with prey (about which more soon) – and both fight with, and learn from, rival groups.
Chris Stringer says that this allowed the acceleration that replaced the ‘two million years of boredom’: ‘Through imitation and peer-group feedback, populations could adapt well beyond the abilities of an isolated genius, whose ideas might never get beyond his or her cave, or might be lost through a sudden death.’6 It may very well be that other Homo groups were also able to speak, plan ahead, and so on, but not so well, and were therefore destroyed by the rate of change in the world around them; or were wiped out (and possibly eaten) by us. Another historian of early people, Brian Fagan, has argued that this new cooperation involved the invention not simply of speech but of abstract thought, ‘a new realm of symbolic meanings, which thrived in a world of partnerships between humans and their surroundings’ and which included, for the first time, art and perhaps religion.
Carrying all this with us, we spread first into Asia and then Europe. We reached the far east of Asia around 40,000 years ago and arrived in the Americas, across the ‘Beringia’ land bridge (long gone), around 20,000 years ago. By 12,000 years ago we had reached the southern areas of South America, and the final areas of human habitation were the islands of the mid-Pacific. Hawaii and New Zealand were reached only a thousand years ago, by people whose culture was still essentially that of the Stone Age yet who had developed impressive star navigation and boat-building. This spread of Homo sapiens is very fast compared with the 1.4 million years or so for the development of our previous ancestor, Homo erectus, into us.7 In biological time, it is like an explosion. Everywhere we arrived, there is evidence of the extinction of other large mammals.
We should rid ourselves of any comfortable or complacent sense that contemporary humans, sitting in coffee bars or driving cars, are superior in intellect to the hunter-gatherers who emerged from those hard African aeons. Hunter-gatherers had to be able to do many more different things than today’s urban people, and it has been estimated that men have lost around a tenth of their brain size compared with the people of the last ice age, and women 14 per cent. The Australian scientist Tim Flannery points out that the same is true of domesticated animals compared with their wild forebears, and for the same reasons: ‘Overall, life for all members of our domesticated mixed feeding flock is made so much more accommodating that its members can invest less of their energy in brains . . . If you doubt how far our civilization has turned us into helpless, self-domesticated livestock, just look at the world around you.’8 This may seem harsh, but it is a useful corrective to our modern condescension. Early humans, driving out of Africa, were extraordinary, rather terrifying creatures.
Caves of Genius
We know more about the first European settlers, the Cro-Magnons, than we do about the first Asians and Australians, but this is more to do with the history of archaeology, and European self-satisfaction, than with anything else. Predictions are dangerous when it comes to early history, but it seems safe to say that the big new discoveries are likely to come in China and other parts of East Asia. Meanwhile, the Europeans enjoy the odd bits of poetry awarded to early cultures by the accident of where their bones were found. They are ‘Aurignacians’, ‘Magdalenians’ or ‘Gravettians’, which is confusing, though better than the preferred modern academic term ‘European Early Modern Humans’, or EEMHs.
So, who were they?
Most people living then would have known only small local groups. It has been estimated that throughout this long period there was rarely a gathering of humans on the planet numbering more than three hundred or so. There must have been breeding across different groups, or the genetic cost would have been horrendous, so there must also have been contact between tribes at the edge of their range. We are sure they had language, but what kind? Settled people in Celtic or Chinese cultures had different dialects in different valleys, altering every few score miles. The same is true in Papua New Guinea, Australia, pre-European North America and the Amazon Basin.
The languages that emerged in different parts of the world are very different from each other, though hints of some original or ‘Ur-languages’ can be traced through common-sounding words. But over larger distances, there are big differences in the way sounds are formed – where in the mouth and throat, how the lips and tongue are used – and the way grammar works. It seems likely that the Cro-Magnon people, like aboriginal Australians, had a kaleidoscope of local dialects and languages with enough familiar words and sounds to allow communication across the edges of rival tribal groups.
We also know that later agricultural societies worshipped deities associated with their survival – gods for water, rain, sun, corn. So it seems likely that hunter-gatherer societies gave a special place to the aspects of nature they relied on most heavily – the animals they killed and used. Today’s hunter-gatherers tend to show reverence for, and close observatory interest in, the birds and animals they live off. African hunters are known to mimic animals they intend to pursue, to try to get inside their thinking. Surely the cave paintings of aurochs and bison have a similar origin? Modern hunter-gatherers also have creation myths, stories about where they came from. It seems unlikely that the darker-skinned earlier versions of ourselves did not have those too.
And indeed, the three hundred or so painted cave sites in Spain and France discovered so far imply a belief system based on animals and the natural world. Looking, drawing, copying – using the hand, eye and memory – seem to constitute a very early human characteristic, and it is always possible that the cave paintings are ‘art for art’s sake’ rather than having a spiritual purpose. Yet the use of cave art by people in Africa and Australia, and the intensely repeated images, suggest some kind of religious system. We have very early bone flutes; and the paintings would have been made in the semi-darkness.
There must have been stories, too. It is not a fantastic leap to imagine music-driven underground rituals intended to ensure that the deer and horses keep migrating, or to honour the giant creatures brought down by spear-throwing hunters. The association of darkness, bulls and mystery is deeply embedded in the European imagination. Similar art may have been made elsewhere, and lost. It may yet emerge in many other places: 6,000-year-old paintings were found recently in a cave in Inner Mongolia, northern China. But what we have in southwestern Europe is a wonderful trumpet-blast for the arrival of fully modern humans, art already quite as accomplished and moving as the later drawings of a Rubens or a Van Gogh.
Our relationship with a closer contemporary relative, the beetle-browed humans we call Neanderthal, is a darker story. These people can be defined as a separate species or a subgroup of our own, and were physically distinct: heavier-boned, with differently shaped skulls and perhaps without full speech. They appear fully developed only around 130,000 years ago and survived in Europe until between 30,000 and 24,000 years ago – though they disappeared earlier in Asia. So as an ‘unsuccessful’ species,
an all-round failure much mocked by cartoonists, they survived, roughly speaking, for 100,000 years – much longer than has Homo sapiens outside Africa so far, and indeed fifty times longer than the period that separates you, reading this, and Christ.
What happened to them? There was no cataclysmic event. Modern humans lived alongside their near-relatives for around thirty thousand years. Scattered archaeological evidence suggests Neanderthals may have copied the new super-hunters, altering their own tools. Biologists fiercely disagree about whether the two groups interbred, and the latest thinking is that probably they did – a little; there is (a little) DNA evidence from some scattered communities. The ‘new people’ clearly enjoyed advantages. The Neanderthals may have used a form of humming or singing communication rather than full-scale language; it has been suggested that because they lived in small groups they did not need to convey complex information, but only emotion.9 So far as we know, though they buried their dead and may even have used makeup, they made no art and did not invent bows, harpoons, needles or jewellery.
They survived well in climatic conditions that we can barely comprehend; the ‘old stone age’ was a time of ice sheets arriving and retreating, testing the flexibility of humans to the utmost. Neanderthals had to rely on the skins of the animals they killed to protect them from the cold, but modern humans had a secret weapon, more important even than their better cutting edges, their spear-throwers or the bows that would allow them to kill from a distance: they had sewing. Many beautifully formed needles have been found, as well as the awls to cut the holes needed for the thread to pass through. As with today’s Inuit people, Cro-Magnon man could dress in clothes that fitted closely and were worn in layers, giving much greater protection and flexibility than bear-hides. Brian Fagan says: ‘The needle allowed women to tailor garments from the fur and skin of different animals, such as wolves, reindeer, and arctic foxes, taking full advantage of each hide or pelt’s unique abilities to reduce the dangers of frostbite and hypothermia in environments of rapidly changing extremes.’