29 THE RESTLESS APESOME
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It was so superior to existing tools that soon others were following the inventor’s lead andmaking hand axes of their own. Eventually whole societies existed that seemed to do littleelse. “They made them in the thousands,” says Ian Tattersall. “There are some places inAfrica where you literally can’t move without stepping on them. It’s strange because they arequite 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 a footand a half long and eight inches wide at its widest point, and handed it to me. It was shapedlike a spearhead, but one the size of a stepping-stone. As a fiberglass cast it weighed only afew ounces, but the original, which was found in Tanzania, weighed twenty-five pounds. “Itwas completely useless as a tool,” Tattersall said. “It would have taken two people to lift itadequately, 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 somesymbolic importance, but we can only guess what.”
The axes became known as Acheulean tools, after St. Acheul, a suburb of Amiens innorthern France, where the first examples were found in the nineteenth century, and contrastwith the older, simpler tools known as Oldowan, originally found at Olduvai Gorge inTanzania. In older textbooks, Oldowan tools are usually shown as blunt, rounded, hand-sizedstones. In fact, paleoanthropologists now tend to believe that the tool part of Oldowan rockswere 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 eventuallybecome 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 theirAcheulean tools, too. They carried them vast distances. Sometimes they even took unshapedrocks 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 andcentral Asia, they have almost never been found in the Far East. This is deeply puzzling.
In the 1940s a Harvard paleontologist named Hallum Movius drew something called theMovius line, dividing the side with Acheulean tools from the one without. The line runs in asoutheasterly direction across Europe and the Middle East to the vicinity of modern-dayCalcutta and Bangladesh. Beyond the Movius line, across the whole of southeast Asia andinto China, only the older, simpler Oldowan tools have been found. We know that Homosapiens went far beyond this point, so why would they carry an advanced and treasured stonetechnology to the edge of the Far East and then just abandon it? />
“That troubled me for a long time,” recalls Alan Thorne of the Australian NationalUniversity in Canberra. “The whole of modern anthropology was built round the idea thathumans came out of Africa in two waves—a first wave of Homo erectus, which became JavaMan and Peking Man and the like, and a later, more advanced wave of Homo sapiens, whichdisplaced the first lot. Yet to accept that you must believe thatHomo sapiens got so far withtheir more modern technology and then, for whatever reason, gave it up. It was all verypuzzling, to say the least.”
As it turned out, there would be a great deal else to be puzzled about, and one of the mostpuzzling findings of all would come from Thorne’s own part of the world, in the outback ofAustralia. In 1968, a geologist named Jim Bowler was poking around on a long-dried lakebedcalled Mungo in a parched and lonely corner of western New South Wales when somethingvery unexpected caught his eye. Sticking out of a crescent-shaped sand ridge of a type knownas a lunette were some human bones. At the time, it was believed that humans had been inAustralia for no more than 8,000 years, but Mungo had been dry for 12,000 years. So whatwas anyone doing in such an inhospitable place?
The answer, provided by carbon dating, was that the bones’ owner had lived there whenLake Mungo was a much more agreeable habitat, a dozen miles long, full of water and fish,fringed by pleasant groves of casuarina trees. To everyone’s astonishment, the bones turnedout to be 23,000 years old. Other bones found nearby were dated to as much as 60,000 years.
This was unexpected to the point of seeming practically impossible. At no time sincehominids first arose on Earth has Australia not been an island. Any human beings who arrivedthere must have come by sea, in large enough numbers to start a breeding population, aftercrossing sixty miles or more of open water without having any way of knowing that aconvenient landfall awaited them. Having landed, the Mungo people had then found their waymore than two thousand miles inland from Australia’s north coast—the presumed point ofentry—which suggests, according to a report in the Proceedings of the National Academy ofSciences, “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 tomost anthropology texts, there’s no evidence that people could even speak 60,000 years ago,much less engage in the sorts of cooperative efforts necessary to build ocean-worthy craft andcolonize island continents.
“There’s just a whole lot we don’t know about the movements of people before recordedhistory,” Alan Thorne told me when I met him in Canberra. “Do you know that whennineteenth-century anthropologists first got to Papua New Guinea, they found people in thehighlands of the interior, in some of the most inaccessible terrain on earth, growing sweetpotatoes. Sweet potatoes are native to South America. So how did they get to Papua NewGuinea? We don’t know. Don’t have the faintest idea. But what is certain is that people havebeen moving around with considerable assuredness for longer than traditionally thought, andalmost certainly sharing genes as well as information.”
The problem, as ever, is the fossil record. “Very few parts of the world are even vaguelyamenable to the long-term preservation of human remains,” says Thorne, a sharp-eyed manwith a white goatee and an intent but friendly manner. “If it weren’t for a few productiveareas like Hadar and Olduvai in east Africa we’d know frighteningly little. And when youlook elsewhere, often wedo know frighteningly little. The whole of India has yielded just oneancient human fossil, from about 300,000 years ago. Between Iraq and Vietnam—that’s adistance of some 5,000 kilometers—there have been just two: the one in India and aNeandertal in Uzbekistan.” He grinned. “That’s not a whole hell of a lot to work with. You’releft with the position that you’ve got a few productive areas for human fossils, like the GreatRift Valley in Africa and Mungo here in Australia, and very little in between. It’s notsurprising that paleontologists have trouble connecting the dots.”
The traditional theory to explain human movements—and the one still accepted by themajority of people in the field—is that humans dispersed across Eurasia in two waves. Thefirst wave consisted of Homo erectus, who left Africa remarkably quickly—almost as soon asthey emerged as a species—beginning nearly two million years ago. Over time, as they settledin different regions, these early erects further evolved into distinctive types—into Java Manand Peking Man in Asia, and Homo heidelbergensis and finally Homo neanderthalensis inEurope.
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 radiatingoutward in a second wave. Wherever they went, according to this theory, these new Homosapiens displaced their duller, less adept predecessors. Quite how they did this has alwaysbeen a matter of disputation. No signs of slaughter have ever been found, so most authoritiesbelieve the newer hominids simply outcompeted the older ones, though other factors may alsohave contributed. “Perhaps we gave them smallpox,” suggests Tattersall. “There’s no real wayof telling. The one certainty is that we are here now and they aren’t.”
These first modern humans are surprisingly shadowy. We know less about ourselves,curiously enough, than about almost any other line of hominids. It is odd indeed, as Tattersallnotes, “that the most recent major event in human evolution—the emergence of our ownspecies—is perhaps the most obscure of all.” Nobody can even quite agree where trulymodern humans first appear in the fossil record. Many books place their debut at about120,000 years ago in the form of remains found at the Klasies River Mouth in South Africa,but not everyone accepts that these were fully modern people. Tattersall and Schwartzmaintain that “whether any or all of them actually represent our species still awaits definitiveclarification.”
The first undisputed appearance of Homo sapiens is in the eastern Mediterranean, aroundmodern-day Israel, where they begin to show up about 100,000 years ago—but even therethey are described (by Trinkaus and Shipman) as “odd, difficult-to-classify and poorlyknown.” Neandertals were already well established in the region and had a type of tool kitknown as Mousterian, which the modern humans evidently found worthy enough to borrow.
No Neandertal remains have ever been found in north Africa, but their tool kits turn up allover the place. Somebody must have taken them there: modern humans are the onlycandidate. It is also known that Neandertals and modern humans coexisted in some fashionfor tens of thousands of years in the Middle East. “We don’t know if they time-shared thesame space or actually lived side by side,” Tattersall says, but the moderns continued happilyto use Neandertal tools—hardly convincing evidence of overwhelming superiority. No lesscuriously, Acheulean tools are found in the Middle East well over a million years ago, but scarcely exist in Europe until just 300,000 years ago. Again, why people who had thetechnology didn’t take the tools with them is a mystery.
For a long time, it was believed that the Cro-Magnons, as modern humans in Europebecame known, drove the Neandertals before them as they advanced across the continent,eventually forcing them to its western margins, where essentially they had no choice but tofall in the sea or go extinct. In fact, it is now known that Cro-Magnons were in the far west ofEurope at about the same time they were also coming in from the east. “Europe was a prettyempty place in those days,” Tattersall says. “They may not have encountered each other allthat often, even with all their comings and goings.” One curiosity of the Cro-Magnons’ arrivalis that it came at a time known to paleoclimatology as the Boutellier interval, when Europewas plunging from a period of relative mildness into yet another long spell of punishing cold.
Whatever it was that drew them to Europe, it wasn’t the glorious weather.
In any case, the idea that Neandertals crumpled in the face of competition from newlyarrived Cro-Magnons strains against the evidence at least a little. Neandertals were nothing ifnot tough. For tens of thousands of years they lived through conditions that no modern humanoutside a few polar scientists and explorers has experienced. During the worst of the ice ages,blizzards with hurricane-force winds were common. Temperatures routinely fell to 50 degreesbelow zero Fahrenheit. Polar bears padded across the snowy vales of southern England.
Neandertals naturally retreated from the worst of it, but even so they will have experiencedweather that was at least as bad as a modern Siberian winter. They suffered, to be sure—aNeandertal who lived much past thirty was lucky indeed—but as a species they weremagnificently resilient and practically indestructible. They survived for at least a hundredthousand years, and perhaps twice that, over an area stretching from Gibraltar to Uzbekistan,which is a pretty successful run for any species of being.
Quite who they were and what they were like remain matters of disagreement anduncertainty. Right up until the middle of the twentieth century the accepted anthropologicalview of the Neandertal was that he was dim, stooped, shuffling, and simian—thequintessential caveman. It was only a painful accident that prodded scientists to reconsiderthis view. In 1947, while doing fieldwork in the Sahara, a Franco-Algerian paleontologistnamed Camille Arambourg took refuge from the midday sun under the wing of his lightairplane. As he sat there, a tire burst from the heat, and the plane tipped suddenly, striking hima painful blow on the upper body. Later in Paris he went for an X-ray of his neck, and noticedthat his own vertebrae were aligned exactly like those of the stooped and hulking Neandertal.
Either he was physiologically primitive or Neandertal’s posture had been misdescribed. Infact, it was the latter. Neandertal vertebrae were not simian at all. It changed utterly how weviewed Neandertals—but only some of the time, it appears.
It is still commonly held that Neandertals lacked the intelligence or fiber to compete onequal terms with the continent’s slender and more cerebrally nimble newcomers, Homosapiens. Here is a typical comment from a recent book: “Modern humans neutralized thisadvantage [the Neandertal’s considerably heartier physique] with better clothing, better firesand better shelter; meanwhile the Neandertals were stuck with an oversize body that requiredmore food to sustain.” In other words, the very factors that had allowed them to survivesuccessfully for a hundred thousand years suddenly became an insuperable handicap.
Above all the issue that is almost never addressed is that Neandertals had brains that weresignificantly larger than those of modern people—1.8 liters for Neandertals versus 1.4 formodern people, according to one calculation. This is more than the difference between modern Homo sapiens and late Homo erectus , a species we are happy to regard as barelyhuman. The argument put forward is that although our brains were smaller, they weresomehow more efficient. I believe I speak the truth when I observe that nowhere else inhuman evolution is such an argument made.
So why then, you may well ask, if the Neandertals were so stout and adaptable andcerebrally well endowed, are they no longer with us? One possible (but much disputed)answer is that perhaps they are. Alan Thorne is one of the leading proponents of an alternativetheory, known as the multiregional hypothesis, which holds that human evolution has beencontinuous—that just as australopithecines evolved into Homo habilis and Homoheidelbergensis became over time Homo neanderthalensis, so modernHomo sapiens simplyemerged from more ancient Homo forms.Homo erectus is, on this view, not a separate speciesbut just a transitional phase. Thus modern Chinese are descended from ancient Homo erectusforebears in China, modern Europeans from ancient European Homo erectus, and so on.
“Except that for me there are no Homo erectus,” says Thorne. “I think it’s a term which hasoutlived its usefulness. For me, Homo erectus is simply an earlier part of us. I believe onlyone species of humans has ever left Africa, and that species isHomo sapiens.”
Opponents of the multiregional theory reject it, in the first instance, on the grounds that itrequires an improbable amount of parallel evolution by hominids throughout the Old World—in Africa, China, Europe, the most distant islands of Indonesia, wherever they appeared. Somealso believe that multiregionalism encourages a racist view that anthropology took a very longtime to rid itself of. In the early 1960s, a famous anthropologist named Carleton Coon of theUniversity of Pennsylvania suggested that some modern races have different sources oforigin, implying that some of us come from more superior stock than others. This hearkenedback uncomfortably to earlier beliefs that some modern races such as the African “Bushmen”
(properly the Kalahari San) and Australian Aborigines were more primitive than others.
Whatever Coon may personally have felt, the implication for many people was that someraces are inherently more advanced, and that some humans could essentially constitutedifferent species. The view, so instinctively offensive now, was widely popularized in manyrespectable places until fairly recent times. I have before me a popular book published byTime-Life Publications in 1961 called The Epic of Man based on a series of articles in Lifemagazine. In it you can find such comments as “Rhodesian man . . . lived as recently as25,000 years ago and may have been an ancestor of the African Negroes. His brain size wasclose to that of Homo sapiens.” In other words black Africans were recently descended fromcreatures that were only “close” to Homo sapiens.
Thorne emphatically (and I believe sincerely) dismisses the idea that his theory is in anymeasure racist and accounts for the uniformity of human evolution by suggesting that therewas a lot of movement back and forth between cultures and regions. “There’s no reason tosuppose that people only went in one direction,” he says. “People were moving all over theplace, and where they met they almost certainly shared genetic material throughinterbreeding. New arrivals didn’t replace the indigenous populations, they joined them. Theybecame them.” He likens the situation to when explorers like Cook or Magellan encounteredremote peoples for the first time. “They weren’t meetings of different species, but of the samespecies with some physical differences.”
What you actually see in the fossil record, Thorne insists, is a smooth, continuoustransition. “There’s a famous skull from Petralona in Greece, dating from about 300,000 yearsago, that has been a matter of contention among traditionalists because it seems in some ways Homo erectus but in other ways Homo sapiens. Well, what we say is that this is just what youwould expect to find in species that were evolving rather than being displaced.”
One thing that would help to resolve matters would be evidence of interbreeding, but that isnot at all easy to prove, or disprove, from fossils. In 1999, archeologists in Portugal found theskeleton of a child about four years old that died 24,500 years ago. The skeleton was modernoverall, but with certain archaic, possibly Neandertal, characteristics: unusually sturdy legbones, teeth bearing a distinctive “shoveling” pattern, and (though not everyone agrees on it)an indentation at the back of the skull called a suprainiac fossa, a feature exclusive toNeandertals. Erik Trinkaus of Washington University in St. Louis, the leading authority onNeandertals, announced the child to be a hybrid: proof that modern humans and Neandertalsinterbred. Others, however, were troubled that the Neandertal and modern features weren’tmore blended. As one critic put it: “If you look at a mule, you don’t have the front endlooking like a donkey and the back end looking like a horse.”
Ian Tattersall declared it to be nothing more than “a chunky modern child.” He accepts thatthere may well have been some “hanky-panky” between Neandertals and moderns, butdoesn’t believe it could have resulted in reproductively successful offspring.
1“I don’t knowof any two organisms from any realm of biology that are that different and still in the samespecies,” he says.
With the fossil record so unhelpful, scientists have turned increasingly to genetic studies,in particular the part known as mitochondrial DNA. Mitochondrial DNA was only discoveredin 1964, but by the 1980s some ingenious souls at the University of California at Berkeley hadrealized that it has two features that lend it a particular convenience as a kind of molecularclock: it is passed on only through the female line, so it doesn’t become scrambled withpaternal DNA with each new generation, and it mutates about twenty times faster than normalnuclear DNA, making it easier to detect and follow genetic patterns over time. By tracking therates of mutation they could work out the genetic history and relationships of whole groups ofpeople.
In 1987, the Berkeley team, led by the late Allan Wilson, did an analysis of mitochondrialDNA from 147 individuals and declared that the rise of anatomically modern humansoccurred in Africa within the last 140,000 years and that “all present-day humans aredescended from that population.” It was a serious blow to the multiregionalists. But thenpeople began to look a little more closely at the data. One of the most extraordinary points—almost too extraordinary to credit really—was that the “Africans” used in the study wereactually African-Americans, whose genes had obviously been subjected to considerablemediation in the past few hundred years. Doubts also soon emerged about the assumed ratesof mutations.
By 1992, the study was largely discredited. But the techniques of genetic analysiscontinued to be refined, and in 1997 scientists from the University of Munich managed toextract and analyze some DNA from the arm bone of the original Neandertal man, and thistime the evidence stood up. The Munich study found that the Neandertal DNA was unlike anyDNA found on Earth now, strongly indicating that there was no genetic connection betweenNeandertals and modern humans. Now this really was a blow to multiregionalism.
1One possibility is that Neandertals and Cro-Magnons had different numbers of chromosomes, a complicationthat commonly arises when species that are close but not quite identical conjoin. In the equine world, forexample, horses have 64 chromosomes and donkeys 62. Mate the two and you get an offspring with areproductively useless number of chromosomes, 63. You have, in short, a sterile mule.
Then in late 2000 Nature and other publications reported on a Swedish study of themitochondrial DNA of fifty-three people, which suggested that all modern humans emergedfrom Africa within the past 100,000 years and came from a breeding stock of no more than10,000 individuals. Soon afterward, Eric Lander, director of the WhiteheadInstitute/Massachusetts Institute of Technology Center for Genome Research, announced thatmodern Europeans, and perhaps people farther afield, are descended from “no more than afew hundred Africans who left their homeland as recently as 25,000 years ago.”
As we have noted elsewhere in the book, modern human beings show remarkably littlegenetic variability—“there’s more diversity in one social group of fifty-five chimps than inthe entire human population,” as one authority has put it—and this would explain why.
Because we are recently descended from a small founding population, there hasn’t been timeenough or people enough to provide a source of great variability. It seemed a pretty severeblow to multiregionalism. “After this,” a Penn State academic told the Washington Post,“people won’t be too concerned about the multiregional theory, which has very littleevidence.”
But all of this overlooked the more or less infinite capacity for surprise offered by theancient Mungo people of western New South Wales. In early 2001, Thorne and his colleaguesat the Australian National University reported that they had recovered DNA from the oldest ofthe Mungo specimens—now dated at 62,000 years—and that this DNA proved to be“genetically distinct.”
The Mungo Man, according to these findings, was anatomically modern—just like you andme—but carried an extinct genetic lineage. His mitochondrial DNA is no longer found inliving humans, as it should be if, like all other modern people, he was descended from peoplewho left Africa in the recent past.
“It turned everything upside down again,” says Thorne with undisguised delight.
Then other even more curious anomalies began to turn up. Rosalind Harding, a populationgeneticist at the Institute of Biological Anthropology in Oxford, while studying betaglobingenes in modern people, found two variants that are common among Asians and theindigenous people of Australia, but hardly exist in Africa. The variant genes, she is certain,arose more than 200,000 years ago not in Africa, but in east Asia—long before modern Homosapiens reached the region. The only way to account for them is to say that ancestors ofpeople now living in Asia included archaic hominids—Java Man and the like. Interestingly,this same variant gene—the Java Man gene, so to speak—turns up in modern populations inOxfordshire.
Confused, I went to see Harding at the institute, which inhabits an old brick villa onBanbury Road in Oxford, in more or less the neighborhood where Bill Clinton spent hisstudent days. Harding is a small and chirpy Australian, from Brisbane originally, with the rareknack for being amused and earnest at the same time.
“Don’t know,” she said at once, grinning, when I asked her how people in Oxfordshireharbored sequences of betaglobin that shouldn’t be there. “On the whole,” she went on moresomberly, “the genetic record supports the out-of-Africa hypothesis. But then you find theseanomalous clusters, which most geneticists prefer not to talk about. There’s huge amounts ofinformation that would be available to us if only we could understand it, but we don’t yet.
We’ve barely begun.” She refused to be drawn out on what the existence of Asian-origin genes in Oxfordshire tells us other than that the situation is clearly complicated. “All we cansay at this stage is that it is very untidy and we don’t really know why.”
At the time of our meeting, in early 2002, another Oxford scientist named Bryan Sykes hadjust produced a popular book called The Seven Daughters of Eve in which, using studies ofmitochondrial DNA, he had claimed to be able to trace nearly all living Europeans back to afounding population of just seven women—the daughters of Eve of the title—who livedbetween 10,000 and 45,000 years ago in the time known to science as the Paleolithic. To eachof these women Sykes had given a name—Ursula, Xenia, Jasmine, and so on—and even adetailed personal history. (“Ursula was her mother’s second child. The first had been taken bya leopard when he was only two. . . .”)When I asked Harding about the book, she smiled broadly but carefully, as if not quitecertain where to go with her answer. “Well, I suppose you must give him some credit forhelping to popularize a difficult subject,” she said and paused thoughtfully. “And thereremains the remote possibility that he’s right.” She laughed, then went on more intently:
“Data from any single gene cannot really tell you anything so definitive. If you follow themitochondrial DNA backwards, it will take you to a certain place—to an Ursula or Tara orwhatever. But if you take any other bit of DNA, any gene at all, and traceit back, it will takeyou someplace else altogether.”
It was a little, I gathered, like following a road randomly out of London and finding thateventually it ends at John O’Groats, and concluding from this that anyone in London musttherefore have come from the north of Scotland. They might have come from there, of course,but equally they could have arrived from any of hundreds of other places. In this sense,according to Harding, every gene is a different highway, and we have only barely begun tomap the routes. “No single gene is ever going to tell you the whole story,” she said.
So genetic studies aren’t to be trusted?
“Oh you can trust the studies well enough, generally speaking. What you can’t trust are thesweeping conclusions that people often attach to them.”
She thinks out-of-Africa is “probably 95 percent correct,” but adds: “I think both sides havedone a bit of a disservice to science by insisting that it must be one thing or the other. Thingsare likely to turn out to be not so straightforward as either camp would have you believe. Theevidence is clearly starting to suggest that there were multiple migrations and dispersals indifferent parts of the world going in all kinds of directions and generally mixing up the genepool. That’s never going to be easy to sort out.”
Just at this time, there were also a number of reports questioning the reliability of claimsconcerning the recovery of very ancient DNA. An academic writing in Nature had noted howa paleontologist, asked by a colleague whether he thought an old skull was varnished or not,had licked its top and announced that it was. “In the process,” noted the Nature article, “largeamounts of modern human DNA would have been transferred to the skull,” rendering ituseless for future study. I asked Harding about this. “Oh, it would almost certainly have beencontaminated already,” she said. “Just handling a bone will contaminate it. Breathing on itwill contaminate it. Most of the water in our labs will contaminate it. We are all swimming inforeign DNA. In order to get a reliably clean specimen you have to excavate it in sterileconditions and do the tests on it at the site. It is the trickiest thing in the world not tocontaminate a specimen.”
So should such claims be treated dubiously? I asked.
Harding nodded solemnly. “Very,” she said.
If you wish to understand at once why we know as little as we do about human origins, Ihave the place for you. It is to be found a little beyond the edge of the blue Ngong Hills inKenya, to the south and west of Nairobi. Drive out of the city on the main highway toUganda, and there comes a moment of startling glory when the ground falls away and you arepresented with a hang glider’s view of boundless, pale green African plain.
This is the Great Rift Valley, which arcs across three thousand miles of east Africa,marking the tectonic rupture that is setting Africa adrift from Asia. Here, perhaps forty milesout of Nairobi, along the baking valley floor, is an ancient site called Olorgesailie, which oncestood beside a large and pleasant lake. In 1919, long after the lake had vanished, a geologistnamed J. W. Gregory was scouting the area for mineral prospects when he came across astretch of open ground littered with anomalous dark stones that had clearly been shaped byhuman hand. He had found one of the great sites of Acheulean tool manufacture that IanTattersall had told me about.
Unexpectedly in the autumn of 2002 I found myself a visitor to this extraordinary site. Iwas in Kenya for another purpose altogether, visiting some projects run by the charity CAREInternational, but my hosts, knowing of my interest in humans for the present volume, hadinserted a visit to Olorgesailie into the schedule.
After its discovery by Gregory, Olorgesailie lay undisturbed for over two decades beforethe famed husband-and-wife team of Louis and Mary Leakey began an excavation that isn’tcompleted yet. What the Leakeys found was a site stretching to ten acres or so, where toolswere made in incalculable numbers for roughly a million years, from about 1.2 million yearsago to 200,000 years ago. Today the tool beds are sheltered from the worst of the elementsbeneath large tin lean-tos and fenced off with chicken wire to discourage opportunisticscavenging by visitors, but otherwise the tools are left just where their creators dropped themand where the Leakeys found them.
Jillani Ngalli, a keen young man from the Kenyan National Museum who had beendispatched to act as guide, told me that the quartz and obsidian rocks from which the axeswere made were never found on the valley floor. “They had to carry the stones from there,” hesaid, nodding at a pair of mountains in the hazy middle distance, in opposite directions fromthe site: Olorgesailie and Ol Esakut. Each was about ten kilometers, or six miles, away—along way to carry an armload of stone.
Why the early Olorgesailie people went to such trouble we can only guess, of course. Notonly did they lug hefty stones considerable distances to the lakeside, but, perhaps even moreremarkably, they then organized the site. The Leakeys’ excavations revealed that there wereareas where axes were fashioned and others where blunt axes were brought to be resharpened.
Olorgesailie was, in short, a kind of factory; one that stayed in business for a million years.
Various replications have shown that the axes were tricky and labor-intensive objects tomake—even with practice, an axe would take hours to fashion—and yet, curiously, they werenot particularly good for cutting or chopping or scraping or any of the other tasks to whichthey were presumably put. So we are left with the position that for a million years—far, farlonger than our own species has even been in existence, much less engaged in continuous cooperative efforts—early people came in considerable numbers to this particular site to makeextravagantly large numbers of tools that appear to have been rather curiously pointless.
And who were these people? We have no idea actually. We assume they were Homoerectus because there are no other known candidates, which means that at their peak—theirpeak —the Olorgesailie workers would have had the brains of a modern infant. But there is nophysical evidence on which to base a conclusion. Despite over sixty years of searching, nohuman bone has ever been found in or around the vicinity of Olorgesailie. However muchtime they spent there shaping rocks, it appears they went elsewhere to die.
“It’s all a mystery,” Jillani Ngalli told me, beaming happily.
The Olorgesailie people disappeared from the scene about 200,000 years ago when the lakedried up and the Rift Valley started to become the hot and challenging place it is today. Butby this time their days as a species were already numbered