A Short History of Nearly Everything: Special Illustrated Edition

by Bill Bryson

  Luckily for us, one did—a group of tool users who seemed to arise from out of nowhere and overlapped with the shadowy and much disputed Homo habilis. This is Homo erectus, the species discovered by Eugène Dubois in Java in 1891. Depending on which sources you consult, it existed from about 1.8 million years ago to possibly as recently as twenty thousand or so years ago.

  According to the Java Man authors, Homo erectus is the dividing line: everything that came before him was apelike in character; everything that came after him was humanlike. Homo erectus was the first to hunt, the first to use fire, the first to fashion complex tools, the first to leave evidence of campsites, the first to look after the weak and frail. Compared with all that had gone before, the species was extremely human in form as well as behaviour, its members long-limbed and lean, very strong (much stronger than modern humans), and with the drive and intelligence to spread successfully over huge areas. To other hominids, Homo erectus must have seemed terrifyingly large, powerful, fleet and gifted. Their brains were vastly more sophisticated than anything the world had seen before.

  Erectus was “the velociraptor of its day,” according to Alan Walker of Penn State University, one of the world’s leading authorities. If you were to look one in the eyes, it might appear superficially to be human, but “you wouldn’t connect. You’d be prey.” According to Walker, it had the body of an adult human but the brain of a baby.

  Although erectus had been known about for almost a century it was known only from scattered fragments—not enough to come even close to making one full skeleton. So it wasn’t until an extraordinary discovery in Africa in the 1980s that its importance—or, at the very least, possible importance—as a precursor species for modern humans was fully appreciated. The remote valley of Lake Turkana (formerly Lake Rudolf) in Kenya is now one of the world’s most productive sites for early human remains, but for a very long time no-one had thought to look there. It was only because Richard Leakey was on a flight that was diverted over the valley that he realized it might be more promising than had been thought. A team was dispatched to investigate, but at first found nothing. Then late one afternoon Kamoya Kimeu, Leakey’s most renowned fossil hunter, found a small piece of hominid brow on a hill well away from the lake. Such a site was unlikely to yield much, but they dug anyway out of respect for Kimeu’s instincts and to their astonishment found a nearly complete Homo erectus skeleton. It was from a boy aged between about nine and twelve who had died 1.54 million years ago. The skeleton had “an entirely modern body structure,” says Tattersall, in a way that was without precedent. The Turkana boy was “very emphatically one of us.”

  Also found at Lake Turkana by Kimeu was KNM-ER 1808, a female 1.7 million years old, which gave scientists their first clue that Homo erectus was more interesting and complex than previously thought. The woman’s bones were deformed and covered in coarse growths, the result of an agonizing condition called hypervitaminosis A, which can only come from eating the liver of a carnivore. This told us, first of all, that Homo erectus was eating meat. Even more surprising was that the amount of growth showed that she had lived weeks or even months with the disease. Someone had looked after her. It was the first sign of tenderness in hominid evolution.

  It was also discovered that Homo erectus skulls contained (or, in the view of some, possibly contained) a Broca’s area, a region of the frontal lobe of the brain associated with speech. Chimps don’t have such a feature. Alan Walker thinks the spinal canal didn’t have the size and complexity to enable speech, that erectus probably would have communicated only about as well as modern chimps. Others, notably Richard Leakey, are convinced they could speak.

  For a time, it appears, Homo erectus was the only hominid species. They were unprecedentedly adventurous and spread across the globe with what seems to have been breathtaking rapidity. The fossil evidence, if taken literally, suggests that some members of the species reached Java at about the same time as, or even slightly before, they left Africa. This has led some hopeful scientists to suggest that perhaps modern people arose not in Africa at all, but in Asia—which would be remarkable, not to say miraculous, as no possible precursor species has ever been found anywhere outside Africa. The Asian hominids would have had to appear, as it were, spontaneously. And anyway, an Asian beginning would merely reverse the problem of their spread; you would still have to explain how the Java people then got to Africa so quickly.

  There are several more plausible alternative explanations for how Homo erectus managed to turn up in Asia so soon after its first appearance in Africa. First, a lot of plus-or-minusing goes into the dating of early human remains. If the actual age of the African bones is at the higher end of the range of estimates or the Javan ones at the lower end, or both, then there is plenty of time for African erectus to find their way to Asia. It is also entirely possible that older erectus bones await discovery in Africa. In addition, the Javan dates could be wrong altogether.

  Kamoya Kimeu, one of the greatest of fossil hunters, patiently searches for chips of bone in the dry earth of northern Kenya. At such an unpromising spot in the 1980s Kimeu made his most famous find: a nearly complete skeleton of a Homo erectus boy. (Credit 28.16)

  What is certain is that some time well over a million years ago, some new, comparatively modern, upright beings left Africa and boldly spread out across much of the globe. They possibly did so quite rapidly, increasing their range by as much as 40 kilometres a year on average, all while dealing with mountain ranges, rivers, deserts and other impediments and adapting to differences in climate and food sources. A particular mystery is how they passed along the west side of the Red Sea, an area of famously punishing aridity now, but even drier in the past. It is a curious irony that the conditions that prompted them to leave Africa would have made it much more difficult to do so. Yet somehow they managed to find their way around every barrier and to thrive in the lands beyond.

  And that, I’m afraid, is where all agreement ends. What happened next in the history of human development is a matter of long and rancorous debate, as we shall see in the next chapter.

  But it is worth remembering, before we move on, that all of these evolutionary jostlings over five million years, from distant, puzzled australopithecine to fully modern human, produced a creature that is still 98.4 per cent genetically indistinguishable from the modern chimpanzee. There is more difference between a zebra and a horse, or between a dolphin and a porpoise, than there is between you and the furry creatures your distant ancestors left behind when they set out to take over the world.

  1 Though Dutch, Dubois was from Eijsden, a town bordering the French-speaking part of Belgium.

  2 Humans are put in the family Hominidae. Its members, traditionally called hominids, include any creatures (including extinct ones) that are more closely related to us than to any surviving chimpanzees. The apes, meanwhile, are lumped together in a family called Pongidae. Many authorities believe that chimps, gorillas and orangutans should also be included in the family Hominidae, with humans and chimps in a subfamily called Homininae. The upshot is that the creatures traditionally called hominids become, under this arrangement, hominins. (Leakey and others insist on that designation.) Hominoidea is the name of the ape superfamily, which includes us.

  3 Absolute brain size does not tell you everything—or possibly sometimes even much. Elephants and whales both have brains larger than ours, but you wouldn’t have much trouble outwitting them in contract negotiations. It is relative size that matters, a point that is often overlooked. As Gould notes, A. africanus had a brain of only 450cc, smaller than that of a gorilla. But a typical africanus male weighed less than 45 kilos, and a female much less still, whereas gorillas can easily top out at over 150 kilos.

  Skull of an early modern human, dating from 90,000 years ago, found at Qafzeh in Israel. Found at the same site were remains of Neandertals, suggesting that here at least the two species coexisted, possibly for thousands of years. (Credit 29.1)

  THE RESTLES
S APE

  Sometime about a million and a half years ago, some forgotten genius of the hominid world did an unexpected thing. He (or very possibly she) took one stone and carefully used it to shape another. The result was a simple teardrop-shaped hand-axe, but it was the world’s first piece of advanced technology.

  It was so superior to existing tools that soon others were following the inventor’s lead and making hand-axes of their own. Eventually whole societies existed that seemed to do little else. “They made them in their thousands,” says Ian Tattersall. “There are some places in Africa where you literally can’t move without stepping on them. It’s strange because they are quite intensive objects to make. It was as if they made them for the sheer pleasure of it.”

  From a shelf in his sunny workroom Tattersall took down an enormous cast, perhaps half a metre long and 20 centimetres wide at its widest point, and handed it to me. It was shaped like a spearhead, but one the size of a stepping stone. As a fibreglass cast it weighed only a few ounces, but the original, which was found in Tanzania, weighed 11 kilograms. “It was completely useless as a tool,” Tattersall said. “It would have taken two people to lift it adequately and even then it would have been exhausting to try to pound anything with it.”

  “What was it used for, then?”

  Tattersall gave a genial shrug, pleased at the mystery of it. “No idea. It must have had some symbolic importance, but we can only guess what.”

  The axes became known as Acheulean tools, after St. Acheul, a suburb of Amiens in northern France, where the first examples were found in the nineteenth century, and contrast with the older, simpler tools known as Oldowan, originally found at Olduvai Gorge in Tanzania. In older textbooks, Oldowan tools are usually shown as blunt, rounded, hand-sized stones. In fact, palaeoanthropologists now tend to believe that the tool parts of Oldowan rocks were the pieces flaked off these larger stones, which could then be used for cutting.

  Now here’s the mystery. When early modern humans—the ones who would eventually become us—started to move out of Africa something over a hundred thousand years ago, Acheulean tools were the technology of choice. These early Homo sapiens loved their Acheulean tools, too. They carried them vast distances. Sometimes they even took unshaped rocks with them to make into tools later on. They were, in a word, devoted to the technology. But although Acheulean tools have been found throughout Africa, Europe and western and central Asia, they are almost never found in the Far East. This is deeply puzzling.

  In the 1940s a Harvard palaeontologist named Hallum Movius drew something called the Movius line, dividing the side with Acheulean tools from the one without. The line runs in a southeasterly direction across Europe and the Middle East to the vicinity of modern-day Calcutta and Bangladesh. Beyond the Movius line, across the whole of southeast Asia and into China, only the older, simpler Oldowan tools have been found. We know that Homo sapiens went far beyond this point, so why would they carry an advanced and treasured stone technology to the edge of the Far East and then just abandon it?

  Two forms of ancient tool. Top: A pointed Acheulean hand-axe. (Credit 29.2a) Bottom: Two rather more primitive Oldowan tools (though in fact experts increasingly think the tool parts of the latter were the flakes chipped off, not the lumps left behind). (Credit 29.2b)

  “That troubled me for a long time,” recalls Alan Thorne of the Australian National University in Canberra. “The whole of modern anthropology was built round the idea that humans came out of Africa in two waves—a first wave of Homo erectus, which became Java Man and Peking Man and the like, and a later, more advanced wave of Homo sapiens, which displaced the first lot. Yet to accept that you must believe that Homo sapiens got so far with their more modern technology and then, for whatever reason, gave it up. It was all very puzzling, to say the least.”

  As it turned out, there would be a great deal else to be puzzled about, and one of the most puzzling findings of all would come from Thorne’s own part of the world, in the outback of Australia. In 1968, a geologist named Jim Bowler was poking around on a long-dried lake bed called Mungo in a parched and lonely corner of western New South Wales when something very unexpected caught his eye. Sticking out of a crescent-shaped sand ridge of a type known as a lunette were some human bones. At the time, it was believed that humans had been in Australia for no more than eight thousand years, but Mungo had been dry for twelve thousand years. So what was anyone doing in such an inhospitable place?

  The arid wastes of Lake Mungo in New South Wales, Australia. In 1968, geologist Jim Bowler found ancient human bones there—the first sign that humans had reached Australia, by sea, thousands of years earlier than anyone had previously thought possible. (Credit 29.3)

  The answer, provided by carbon dating, was that the bones’ owner had lived there when Lake Mungo was a much more agreeable habitat, 20 kilometres long, full of water and fish, fringed by pleasant groves of casuarina trees. To everyone’s astonishment, the bones turned out to be twenty-three thousand years old. Other bones found nearby proved to be as much as sixty thousand years old. This was unexpected to the point of seeming practically impossible. At no time since hominids first arose on Earth has Australia not been an island. Any human beings who arrived there must have come by sea, in large enough numbers to start a breeding population, after crossing 100 kilometres or more of open water without having any way of knowing that a convenient landfall awaited them. Having landed, the Mungo people had then found their way over 3,000 kilometres inland from Australia’s north coast—the presumed point of entry—which suggests, according to a report in the Proceedings of the National Academy of Sciences, “that people may have first arrived substantially earlier than 60,000 years ago.”

  How they got there and why they came are questions that can’t be answered. According to most anthropology texts, there’s no evidence that people could even speak sixty thousand years ago, much less engage in the sorts of co-operative efforts necessary to build ocean-worthy craft and colonize island continents.

  “There’s just a whole lot we don’t know about the movements of people before recorded history,” Alan Thorne told me when I met him in Canberra. “Do you know that when nineteenth-century anthropologists first got to Papua New Guinea, they found people in the highlands of the interior, in some of the most inaccessible terrain on earth, growing sweet potatoes. Sweet potatoes are native to South America. So how did they get to Papua New Guinea? We don’t know Don’t have the faintest idea. But what is certain is that people have been moving around with considerable assuredness for longer than traditionally thought, and almost certainly sharing genes as well as information.”

  The problem, as ever, is the fossil record. “Very few parts of the world are even vaguely amenable to the long-term preservation of human remains,” says Thorne, a sharp-eyed man with a white goatee and an intent but friendly manner. “If it weren’t for a few productive areas like Hadar and Olduvai in east Africa we’d know frighteningly little. And when you look elsewhere, often we do know frighteningly little. The whole of India has yielded just one ancient human fossil, from about three hundred thousand years ago. Between Iraq and Vietnam—that’s a distance of some five thousand kilometres—there have been just two: the one in India and a Neandertal in Uzbekistan.” He grinned. “That’s not a whole hell of a lot to work with. You’re left with the position that you’ve got a few productive areas for human fossils, like the Great Rift Valley in Africa and Mungo here in Australia, and very little in between. It’s not surprising that palaeontologists have trouble connecting the dots.”

  The remains of the skeleton known as Mungo Man, discovered in 1974 in New South Wales, turned out to be an astonishing 23,000 years old. Nearby bones proved to be as much as 60,000 years old. How and why these early humans arrived on this island continent is a mystery. (Credit 29.4)

  The traditional theory to explain human movements—and the one still accepted by the majority of people in the field—is that humans dispersed across Eurasia in two w
aves. The first wave consisted of Homo erectus who left Africa remarkably quickly—almost as soon as they emerged as a species—beginning nearly two million years ago. Over time, as they settled in different regions, these early erects further evolved into distinctive types—into Java Man and Peking Man in Asia, and into Homo heidelbergensis and finally Homo neanderthalensis in Europe.

  Then, something over a hundred thousand years ago, a smarter, lither species of creature—the ancestors of every one of us alive today—arose on the African plains and began radiating outwards in a second wave. Wherever they went, according to this theory, these new Homo sapiens displaced their duller, less adept predecessors. Quite how they did this has always been a matter of disputation. No signs of slaughter have ever been found, so most authorities believe the newer hominids simply outcompeted the older ones, though other factors may also have contributed. “Perhaps we gave them smallpox,” suggests Tattersall. “There’s no real way of telling. The one certainty is that we are here now and they aren’t.”