Chapter Content
**Chapter 43: The Restless Apes**
Around a million and a half years in the past, within the hominid lineage, an unsung innovator committed an act of unforeseen genius. This individual—more likely a woman, perhaps—selected a rough stone and meticulously, patiently, began to reshape it against another. The fruit of this labor was a teardrop-shaped hand axe. Crude, yes, but nonetheless a pioneering example of advanced toolmaking.
Superior to anything then in existence, its design was rapidly adopted. Soon, the entire hominid world seemed consumed by its production. "They crafted literally thousands of these things," observed Ian Tattersall. "In some parts of Africa, you can scarcely set foot without stumbling over one. It's a curious thing, because they took considerable effort to manufacture. They made them as if driven by pure, unadulterated enjoyment."
Within the radiant confines of his studio, Tattersall plucked a formidable replica from his shelves and presented it to me. Nearly half a meter in length, it spanned roughly twenty centimeters at its widest point. Shaped like a spearhead, but the size of a paving stone, it was a fiberglass model weighing perhaps 150 grams. The original, unearthed in Tanzania, would have weighed a staggering eleven kilograms. "Utterly impractical as a tool," Tattersall declared. "It would require two individuals simply to lift it, and even then, delivering a blow would be a Herculean feat."
“So, what was its purpose?” I queried.
Tattersall merely offered a faint shrug, a glint of amusement in his eyes at the riddle it posed. "Who knows? Perhaps it served some symbolic function. We can only speculate."
These hand axes, later known as Acheulean tools – named after Saint-Acheul, a suburb of Amiens in northern France, where the initial specimens were identified in the 19th century – were distinct from the older, more primitive Oldowan implements. The latter were first identified in Tanzania’s Olduvai Gorge, hence their designation. In older texts, Oldowan tools are often portrayed as dull, rounded pebbles, easily grasped. Present-day paleoanthropologists contend that Oldowan tools were flakes struck from larger stones, used for cutting and slicing.
Here's the enigma: when early modern humans, who would eventually give rise to us, began migrating out of Africa, roughly 100,000 years ago, Acheulean tools were at the peak of their sophistication. And these early *Homo sapiens* demonstrated a pronounced fondness for these tools. They carried them vast distances, sometimes even transporting unshaped stones for later conversion into implements. Simply put, they were infatuated with this form of craftsmanship. Yet, despite their widespread discovery in Africa, Europe, and parts of Asia, Acheulean tools are conspicuously scarce in the Far East. It’s a persistent puzzle.
In the 1940s, a Harvard paleontologist named Hallam Movius conceived a demarcation, “the Movius Line,” separating Acheulean-using regions from those that didn't. This line arced southeast across Europe, the Middle East, ending somewhere in modern-day Kolkata and Bangladesh. Beyond this boundary, encompassing Southeast Asia and China, only older, cruder Oldowan implements have been found. Given that *Homo sapiens* ventured far beyond this line, why would they abandon such a treasured piece of technology so close to the Far East?
"It was a question that plagued me for years," recalled Alan Thorne from the Australian National University in Canberra. "The established narrative of human evolution rests on the notion of two separate migrations from Africa. First, *Homo erectus*, who became Java Man, Peking Man, and so on. Then, a later, more advanced wave of *Homo sapiens* superseded them. But to accept that, you have to believe that *Homo sapiens* carried relatively modern tools vast distances, only to mysteriously discard them for some unknown reason. At the very least, it’s perplexing."
Subsequent discoveries confirmed that many more mysteries were afoot. One of the most bewildering came from the Australian Outback, Alan Thorne's home territory. In 1968, a geologist named Jim Bowler was prospecting in a desolate region of New South Wales, surveying the dried bed of Lake Mungo, when something unexpected caught his eye. Emerging from a crescent-shaped dune were the unmistakable fragments of human bone. Back then, it was believed that humans had only inhabited Australia for about 8,000 years, yet Lake Mungo had been dry for some 12,000 years. What brought anyone to such a forsaken place?
Radiocarbon dating revealed the bones belonged to an individual who lived when Lake Mungo was still a habitable environment – a 20-kilometer expanse of water, teeming with fish, surrounded by groves of casuarina trees. To everyone’s astonishment, the bones were 23,000 years old! Other finds in the area were even older, dating back as far as 60,000 years. It was stunning, almost unfathomable. Australia had been an isolated landmass since the dawn of hominids. Any arrival would have necessitated seafaring, and in sufficient numbers to ensure survival, crossing over 100 kilometers of water with no clear knowledge of what lay beyond. And after landing, likely on the northern coast, these Mungo people ventured over 3,000 kilometers inland. This, as noted in a report by the Australian National Science Association, suggested that “the initial arrival of humans was considerably earlier than 60,000 years ago.”
How did they get there? Why would they go there? These questions persist. Most anthropological literature maintains that humans lacked the cognitive capacity for speech, let alone the organized cooperation necessary to build seaworthy vessels and venture across oceans to colonize new lands 60,000 years ago.
"We know so little about the movements of prehistoric peoples," Alan Thorne told me when I met him in Canberra. "Did you know that when anthropologists first entered the highlands of Papua New Guinea in the 19th century, they discovered people cultivating sweet potatoes—in some of the most inaccessible locations on Earth? Sweet potatoes originated in South America. How did they get to Papua New Guinea? We haven’t the slightest idea. None whatsoever. But it certainly demonstrates that people were migrating with purpose, far earlier than previously thought, and almost certainly sharing not only genes, but information as well."
As always, the problem lies in the fossil record. "There are so few places on Earth suitable for the long-term preservation of human remains," Thorne explained, a keen intellect radiating from behind his neatly trimmed grey beard and a calm, observant demeanor. "If it weren't for the abundance of fossils unearthed at Hadar and Olduvai in East Africa, we'd know next to nothing. Elsewhere, we know precious little. The entirety of India has yielded only a single ancient hominid fossil dating back about 300,000 years. Between Iraq and Vietnam—a distance of 5,000 kilometers—there are just two fossils: one in India, and a Neanderthal found in Uzbekistan." He chuckled. "There's just not enough bloody stuff to study. So, we’re left with a few regions with relatively rich fossil records, like the East African Rift Valley and here at Lake Mungo in Australia. But there’s next to nothing connecting the dots between these areas, so it’s hardly surprising that paleoanthropologists struggle to weave a cohesive narrative.”
The prevailing theory—still embraced by most in the field—to explain human migrations into Eurasia postulates two distinct waves. The first wave consisted of *Homo erectus*, who migrated out of Africa with incredible speed (almost as soon as they arose). This exodus commenced around 2 million years ago. They settled in diverse regions, and these early *Homo erectus* populations evolved into unique hominid varieties: Java Man and Peking Man in Asia; *Homo heidelbergensis* and ultimately the Neanderthals in Europe.
Then, about 100,000 years ago, a more adaptable species, the ancestors of everyone alive today, emerged on the African plains and embarked on a second wave of migration. According to this theory, these new *Homo sapiens* supplanted their less sophisticated predecessors wherever they encountered them. But the mechanics of this replacement have been fiercely debated. No massacres have been documented, so most experts believe that the newcomers simply outcompeted the old, though other factors may have been at play. "Perhaps we introduced smallpox," Tattersall suggested. "It's impossible to be certain. What’s undeniable is that we’re here, and they’re not.”
The precise origins of these early modern humans remain murky. Paradoxically, we know less about ourselves than almost any other hominid branch. Tattersall remarked, "The most recent major event in human evolution—the emergence of our own species—is perhaps the most shrouded in mystery." Even the location of the earliest modern human fossils is contested. Many books cite fossils from Klasies River Mouth in South Africa, dated to around 120,000 years ago. However, not everyone agrees that they represent fully modern humans. In the eyes of Tattersall and Schwartz, "Whether some or all of them represent our own species remains to be more firmly established."
It's generally accepted that *Homo sapiens* first appeared in the eastern Mediterranean, in what is now Israel, around 100,000 years ago. Yet, even there, they are described (by Trinkaus and Shipman) as "fragmentary, difficult to classify, and poorly understood." Neanderthals had already settled in the region, employing a tool technology known as Mousterian, which the later modern humans apparently found worth emulating. No Neanderthal fossils have been unearthed in North Africa, but Mousterian tools are prevalent. Someone had to have brought them there: the only likely candidate being the modern humans. Furthermore, it is known that Neanderthals and modern humans coexisted in the Middle East for tens of thousands of years. "Whether they cohabited the same locations, or simply occupied neighboring territories, we do not know,” Tattersall mused. "However, the modern humans were quite content to continue using Neanderthal tools—so, it's difficult to determine who had the upper hand." Equally perplexing is the fact that Acheulean tools have been found dating back one million years in the Middle East, but only 300,000 years in Europe. Once more, why would toolmakers capable of such sophistication not carry those tools with them?
For a long time, it was thought that the Cro-Magnons, the early modern humans of Europe, pushed the Neanderthals ahead of them, forcing them into the westernmost extremities of the continent, where they were compelled to either leap into the sea or perish. In truth, we now understand that Cro-Magnons existed in the far west even as others advanced inland from the east. “Europe was virtually unpopulated at that point,” Tattersall said. “Even as they crisscrossed the landscape, they would have struggled to run into each other.” Adding to the puzzle of the Cro-Magnon arrival is the fact that Europe was entering what paleoclimatologists refer to as the Port Talbot Interstadial, a sudden shift from relatively mild conditions into another prolonged cold spell. Whatever compelled the Cro-Magnons to Europe, it wasn't a glacial retreat.
Regardless, the notion that the Neanderthals were utterly defeated by their Cro-Magnon competitors conflicts, at least somewhat, with the archeological evidence. The Neanderthals were exceptionally resilient, enduring conditions that few modern polar scientists or explorers have ever encountered for tens of thousands of years. At the height of the Ice Age, blizzards and hurricane-force winds were commonplace. Temperatures frequently plunged to minus 45 degrees Celsius, and polar bears roamed the valleys of southern England. The Neanderthals naturally retreated during the coldest periods, but even then, they had to endure a climate as dreadful as that of modern-day Siberia. They undoubtedly suffered—a Neanderthal who lived past 30 was exceptionally fortunate—but as a species, they were adaptable and tenacious. They survived for at least 100,000 years, possibly 200,000, from Gibraltar to Uzbekistan. By any measure, a remarkable success.
Their true nature, their appearance, remains elusive. Until the mid-20th century, the prevalent view was that Neanderthals were clumsy, stooped creatures, barely distinguishable from apes—cavemen par excellence. A painful accident prompted a reassessment. In 1947, a French-Algerian paleontologist named Camille Arambourg was working in the Sahara. Seeking shelter from the midday sun, he rested under the wing of his light aircraft. While seated there, a tire burst from the heat, causing the plane to tilt abruptly, striking him forcefully on the back. Subsequent X-rays in Paris revealed a spinal alignment identical to the hunched, lumbering Neanderthals. Either he was physiologically akin to a primitive hominid, or our understanding of Neanderthal posture was flawed. The latter proved to be the case. Neanderthal spines differed dramatically from those of apes. This altered our view of Neanderthals, but the realization seemed to fade.
Even today, many assume that Neanderthals lacked the intellect of the more agile, larger-brained *Homo sapiens*. Here's a typical assertion from a recent book: “Modern humans overcame this advantage [the Neanderthal’s superior physical strength] with warmer clothing, better fire-starting techniques, and improved shelters, while the Neanderthals were hampered by their bulky physiques, which demanded greater caloric intake.” In other words, the very traits that enabled their survival for over 100,000 years suddenly became crippling liabilities.
Crucially, one question is seldom addressed: Neanderthal brains were demonstrably *larger* than those of modern humans, an estimated 1.8 liters compared to our 1.4 liters. This disparity surpasses the difference between modern *Homo sapiens* and late-*Homo erectus*, whom we readily dismiss as less than human. The argument presented is that, somehow, our smaller brains are more efficient. I should note that such an extraordinary claim is rarely seen elsewhere in the context of human evolution.
So, one might ask, if Neanderthals were so strong, adaptable, and well-endowed cerebrally, why are they not still with us? One answer (albeit a highly contentious one) suggests they may still be here. Alan Thorne is a leading proponent of the "multiregional origin" hypothesis, which argues that human evolution was a continuous process—from *Australopithecus* to *Homo habilis* to *Homo heidelbergensis* to Neanderthals, eventually culminating in modern *Homo sapiens*. According to this view, *Homo erectus* was not a distinct species, but merely a transitional phase. Thus, modern Chinese are descended from ancient Chinese *Homo erectus*, modern Europeans from ancient European *Homo erectus*, and so on. "I don't think there's any such thing as *Homo erectus*," Thorne stated. "I think the concept is obsolete. I believe that *Homo erectus* was merely an early stage of *Homo sapiens*. In my view, there was only one human species that left Africa: *Homo sapiens*."
Detractors of the multiregional theory immediately dismiss this notion, arguing that it requires the hominids of the ancient world—Africa, China, Europe, even the remotest islands of Indonesia—to have evolved in a parallel fashion, which is improbable. Some also suspect that the theory subtly reinforces racist ideas, something the field of anthropology has long strived to discard.
In the early 1960s, Carleton Coon, a distinguished anthropologist at the University of Pennsylvania, argued that some modern races had separate origins. He implied that some of us descended from superior lineages, a disturbing echo of older notions that saw certain minorities—the San of Africa or Australian Aborigines—as more primitive.
Regardless of Carleton Coon's intentions, his claim implied that some races were innately superior, with some potentially composing distinct species. Such viewpoints, abhorrent today, were once openly promoted in many respectable forums. I have in my possession a 1961 Time-Life publication, "The Epic of Man," based on a series of *Life* magazine articles. One can read such passages as "Rhodesian Man…lived nearly 25,000 years ago and was probably ancestral to the Negroes of Africa. His brain capacity was only 'approaching that of Homo sapiens.'" In other words, the ancestors of black Africans only "approached" being *Homo sapiens*.
Carleton Coon firmly denied (and I'm sure rightfully so) that his theories carried any racist undercurrents. He believed that the recurring exchanges between different cultures and regions demonstrated the commonality of human evolution. "There's no reason to assume that humans only evolved in one direction," he asserted. "Humans migrated around the world and almost certainly shared genes through interbreeding where they met. Newcomers didn’t supplant indigenous populations, but blended with them, eventually becoming one." He likened it to the encounters of explorers like Cook and Magellan with inhabitants of remote regions: “They didn’t encounter different races, but merely the same human species with certain physical distinctions.”
Thorne maintains that one observes a continuous, even transition in human fossils. The famous skeleton from Petralona, Greece, dating back roughly 300,000 years, has long fueled debates among traditionalists, as it seems to display traits of both *Homo erectus* and *Homo sapiens*. “What does that tell you? That this is exactly what you would expect to see in a species: they are evolving, not being replaced.”
Evidence of interbreeding would assist in answering these questions, but it's incredibly difficult to prove or disprove through fossil evidence. In 1999, Portuguese archeologists unearthed the remains of a 4-year-old child who died 24,500 years ago. Overall, the skeleton appeared to be that of a modern human, but with ancient, perhaps Neanderthal, features: robust leg bones, prominent teeth, and, controversially, a ridged indentation on the back of the skull known as the occipital bun, which is a distinctive Neanderthal trait. Erik Trinkaus of Washington University in St. Louis, a leading authority on Neanderthals, declared the child a hybrid, proof of interbreeding between modern humans and Neanderthals. Others were unconvinced by the blend of Neanderthal and modern features. As one critic pointed out: “If you look at a mule, it doesn’t look like a donkey from the front, and a horse from the back.”
Ian Tattersall dismisses the boy as simply "a robust modern human child." He acknowledges that a certain amount of so-called "hybridization" may have occurred between Neanderthals and modern humans, but doubts they produced fertile offspring. (It's possible that Neanderthals and Cro-Magnons had different numbers of chromosomes, a common complexity when closely related but not identical animals mate. In domesticated animals, for example, horses have 64 chromosomes, while donkeys have 62. The resulting offspring has 63 non-reproductive chromosomes. Simply put, a sterile mule.)
“In the realm of biology, I'm not aware of any two creatures so different that still belong to the same species,” he said.
Since the fossil record is of limited help, scientists have increasingly turned to genetics, particularly mitochondrial DNA. Discovered in 1964, mitochondrial DNA possesses two unique characteristics that make it a convenient molecular clock. First, it's inherited exclusively through the maternal line, thus avoiding recombination with paternal DNA. Second, its mutation rate is twenty times faster than that of nuclear DNA, making its genetic patterns easier to trace. By tracking mutation events, one can determine the genetic history of humans, and the interrelationships between genomes.
In 1987, a team of scientists at the University of California at Berkeley, led by Allan Wilson, analyzed the mitochondrial DNA of 147 individuals. They concluded that anatomically modern humans emerged in Africa within the last 140,000 years. "All of us today are descendants of that population." For the multiregional origin theorists, this was a severe blow. However, further scrutiny was applied to the data. To almost everyone’s surprise, the supposed “Africans” in the study turned out to be African-Americans, whose genetic makeup had obviously been significantly altered over the previous centuries. Furthermore, doubts quickly arose over the assumed mutation rate.
By 1992, the study was largely discredited, but techniques in genetic analysis continued to evolve. In 1997, scientists at the University of Munich extracted and analyzed DNA from the arm bone of a primordial Neanderthal. This time, more compelling evidence emerged. The Munich researchers found that Neanderthal DNA was distinct from any DNA discovered on Earth today, indicating that Neanderthals shared no genetic link with modern humans. This was truly a devastating blow to the multiregional hypothesis.
Then, in late 2000, *Nature* and other publications reported on a study of the mitochondrial DNA from 53 individuals, led by Swedish scientists. The study claimed that all modern humans emerged in Africa within the last 100,000 years, descending from a population of no more than 10,000 individuals. Soon afterward, Eric Lander, director of the Whitehead Institute at MIT, announced that modern Europeans, and perhaps some people much further afield, were descendants of “a few hundred Africans who left their homeland no later than 25,000 years ago."
As we discussed elsewhere in the book, modern human genetic diversity is minimal – with a notable authority stating that “a community of 55 chimpanzees show more genetic variation than all of humanity”, that is to say – because we recently descended from a small group of ancestors, with insufficient time and not enough individuals to create a diversity of genes. This would seem like a hammer blow to the "Multi-regional" theory. "In the future," a Pennsylvania State University researcher told the *Washington Post*, “people will pay much less attention to the multi-regional theory, because there's so little support for it."
However, in the midst of all this, it was almost forgotten that the ancient Mungo Man of western New South Wales had a certain knack for providing unexpected news. In early 2001, Thorne and his colleagues at the Australian National University announced that they had extracted DNA from one of the oldest Mungo specimens—dating back 62,000 years. Analysis indicated the DNA "possessed a unique genetic sequence."
Based on these findings, Mungo Man was anatomically modern – like you and me – yet carried an extinct genetic line. His mitochondrial DNA is nowhere to be found in living humans, as it should be if he were a descendant of Africans who left Africa in the recent past.
"Once again, everything is turned upside down," Thorne said with evident glee.
Then, other strange anomalies surfaced. Rosaline Harding, a human geneticist at Oxford University's Institute of Biological Anthropology, discovered two variants in the globin genes of modern humans. These variants were common among Asians and Australian Aborigines, but almost absent in Africans. She believed this distinct gene originated about 200,000 years ago, but not in Africa; rather, in East Asia, long before modern *Homo sapiens* arrived there. The only plausible explanation was that the ancestors of today's Asians included ancient hominids such as Java Man. Interestingly, the same variant gene—the Java Man gene, so to speak—appeared in modern humans in Oxfordshire.
Perplexed, I visited Harding at her institute, housed in an old brick villa on Banbury Road in Oxford. Harding was petite, amiable, and from Brisbane, Australia. She possessed a rare combination of diligence and good humor.
I asked her why this globin gene, that shouldn't be there, appeared in the people of Oxfordshire. "I don't know," she responded with a knowing smile. "The genetic record generally supports the 'Out of Africa' hypothesis." More gravely, she added, "But then you find these anomalies, which most geneticists prefer not to discuss. Even if we can explain them, we still need to gather a vast amount of information, and we haven't. We've only just started." She offered nothing but that the situation was complex and declined to comment about Asian hominids genes appearing in Oxfordshire. "At this point, we can only say that it's highly unusual, but we don't know why."
Our meeting took place in early 2002, shortly after another Oxford scientist, Bryan Sykes, published the popular book, "The Seven Daughters of Eve." Drawing on mitochondrial DNA research, he claimed to trace the ancestry of nearly all living Europeans to just seven women—the daughters of Eve—who lived between 45,000 and 10,000 years ago, or the Paleolithic Age. Sykes gave these seven women names: Ursula, Xenia, Jasmine, and provided detailed biographies ("Ursula was the second child of her mother. Her first was taken by a leopard when she was two…")
When I mentioned the book to Harding, she chuckled politely, as though unsure how to respond. "Well…I think you have to give him some credit for making a rarefied subject accessible," she said, pausing thoughtfully. "There's a one-in-ten-thousand chance that he's correct." She laughed heartily, and then ruminated, "No single gene tells you anything conclusive. If you follow one line of mitochondrial DNA, it might take you somewhere—Ursula, Jasmine, or someone else. But if you select any other line of mitochondrial DNA, and follow it in the same way, it will probably take you somewhere completely different.”
I suggested it was a bit like choosing a random road out of London and finding yourself in John O'Groats, the northernmost point of Scotland, then concluding that all Londoners originate in the Scottish Highlands. They *could* be from there, but they could also be from countless other locations. In that sense, according to Harding, each gene is a separate highway, and we've only just begun to chart their routes. “No one gene reflects the overall picture,” she said.
So, are genetic studies untrustworthy?
"Oh, generally speaking, you can trust this type of study to a considerable extent. What you can't trust are the conclusions that people insist on drawing.”
She believes the “Out of Africa” theory may be “95 percent correct”, but she adds, "I think it's unscientific for both sides to insist on an all-or-nothing scenario. In the end, it’s likely to prove that things are not as simple as either side believes. Evidence has begun to suggest that there were several migrations of ancient humans in different directions in different parts of the world, and that all of those threads were woven into the entire human gene pool. Sorting it all out is by no means easy."
Around this time, reports surfaced challenging the integrity of extracted ancient DNA. A scholar wrote in *Nature* about a colleague of a paleontologist who inquired whether an ancient skull had been painted, then licked the top of the skull and declared it had been. “In the process,” the *Nature* article stated, “a considerable amount of modern human DNA would have transferred to the skull.” This would render the skull unusable. I spoke to Harding about this. “Oh, it’s almost certainly contaminated,” she said. "Just touching the bone contaminates it. Breathing on it contaminates it. The water in my lab contaminates it. We are surrounded by alien DNA. To obtain a reliable, clean sample, you have to excavate under sterile conditions and conduct the tests on-site. Nothing is more difficult than avoiding contamination.”
Should all these conclusions be viewed with suspicion? I asked. Harding nodded solemnly. "Of course," she said.
If you wanted to immediately know why we understood so little about the origins of man, I could lead you to a place that lay close to the edge of the Ngong Hills of Kenya, southwest of Nairobi. As you drive east from Nairobi, on the fast trunk road headed toward Uganda, ascending a high ridge you would behold the panoramic glory of the almost limitless green expanse of the African plains.
This was the start of the Great Rift Valley which, for 4,800 kilometres ran through eastern Africa. It was by this cracked seam in the earth’s crust that Africa was drifting away from Asia. Here, sixty-five kilometres from Nairobi and near the dry floor of the valley, lay the ancient site of Olorgesailie, which long ago lay beside the shores of a great lake. In 1919, long after the lake had dried, a geologist called J W Gregory came to the region in search of minerals. Traversing an open area, he noticed several strange, dark stones scattered on the ground with the clear signs of workmanship. He had discovered one of the most important Acheulean toolmaking sites that Ian Tattersall had told me about.
In the autumn of 2002, I by chance found myself visiting this magical location. I was in Kenya on a different mission entirely, visiting some aid projects from the US Agency for International Development, but my hosts, aware that I was researching the origins of man for this book, included a visit to Olorgesailie in the program.
For over twenty years after the geologist Gregory had discovered the place, nobody visited Olorgesailie. Then, a team of archeologists, under the celebrated partnership of Louis and Mary Leakey, came to the site and started to excavate, a work that remains incomplete to this day. What the Leakeys had found was a forty-thousand-square-meter zone where, for almost one million years, from about 1.2 million years ago to 200,000 years ago, countless stone tools had been fashioned. Today, the manufacturing sites are roofed with corrugated iron to ward off the weather, and surrounded by chain-link fencing to prevent unscrupulous visitors from theft. Apart from this, the stones remained precisely where their makers had left them, and where the Leakeys had discovered them.
Gilani Angori, a neat young man from the National Museums of Kenya, was assigned to be my guide. He told me that the quartz and obsidian from which the early men had manufactured the hand-axes were nowhere to be found in the valley floor. “They had to bring the stones from over there,” he said, nodding towards two distant, cloud-wreathed mountains: Olorgesailie Mountain and Ol Esakut Mountain. Both were perhaps ten kilometres away – not a short distance to carry an armload of rocks.
Of course, we could not know why the ancient Olorgesailie men went to all this trouble. Not only did they carry heavy rocks a considerable distance to the lake shore, but even more amazingly, they clearly organized their labour at the site. The Leakey’s excavations had demonstrated that there was a designated area for manufacturing the axes and other areas where they were sharpened. In a certain sense, Olorgesailie was a factory, a factory that had been in continuous operation for almost one million years.
Various replicas demonstrate that a hand-axe was quite a sophisticated tool to manufacture, but required great effort – even an expert would require several hours to make one tool – and yet, rather strangely, it was not particularly well-suited to its likely intended use, such as cutting, chopping, scraping and so on. It thus seemed incredible that for one million years – a period vastly longer than our modern human existence, without the advantage of continual, communal working – a considerable number of ancient hominids would travel to this specific location, and manufacture so many tools.
And who were these men? We simply could not know. We assumed that they were Homo erectus, because we knew of no other suitable men. This would mean that, at their peak, these Olorgesailie workers might have possessed brains roughly comparable to a modern human infant, but there was no hard evidence to support this. Despite over sixty years of digging, no human fossils had been discovered at or near Olorgesailie. Whatever time they spent there making stones, when they died, they did so somewhere else.
"All of this is a mystery," Gilani Angori said to me with a cheerful smile.
The men of Olorgesailie had disappeared around 200,000 years ago, as the lake dried up and the Rift Valley region began to become the arid and inhospitable place that it is today. By then, their time as a species had not long to run. The world was about to find its first true ruler: Homo sapiens. Things would never be the same.