Out of Eden: The Peopling of the World

by Oppenheimer, Stephen

  Figure 1.7 Timeline of climatic events and human expansions. The interglacial 125,000 years ago allowed the first northern exit. A climatic downturn at 85,000 years affected Red Sea salinity and may have prompted the southern exit. Toba’s explosion caused genetic bottlenecks both in and outside Africa. An ice age at 65,000 years then allowed access to Australia, while two clusters of interstadials from 50,000 years allowed colonization of Europe.

  If our ancestors left Africa 85,000 years ago, their descendants would have anticipated the Toba explosion in Sumatra by 11,000 years (see Figure 1.7), and beachcombers around the Indian Ocean would have been in direct line for the greatest volcanic ash fall in the whole of human existence. The Toba eruption is thus a valuable date mark, since the ash covered such a wide area, is accurately dated, and can be identified wherever an undisturbed layer of it is found.

  Malaysian archaeologist Zuraina Majid has explored the remains of a modern human culture in a wooded valley in Perak State, near Penang. A continuous Palaeolithic tradition known as the Kota Tampan culture goes back tens of thousands of years there. At one site, tools from this tradition lie embedded in volcanic ash from Toba.43 If the association with modern humans is confirmed, this means that modern humans got to Southeast Asia before the Toba eruption – more than 74,000 years ago. This, in turn, makes the 85,000-year-old exodus more likely. Equally, genetic and other evidence for a human occupation of Australia by 65,000 years ago fits this scenario. The Toba event specifically blanketed the Indian subcontinent in a deep layer of ash. It is difficult to see how India’s first colonists could have survived this greatest of all disasters. So, we could predict a broad human extinction zone between East and West Asia. Such a deep east-west division, or ‘furrow’, is still seen clearly in the genetic record.

  How does such an early date for the exodus fit with the genetic data? This is perhaps the most controversial and exciting part of the story. The short answer is that the genetic dates and tree fit the early exodus well (see Chapters 3 and 4). This also resolves the question I left hanging earlier about the origins of the Europeans: why it was that Europe was colonized only after 50,000 years ago, yet arose from the same maternal ancestor as the Australians and Asians.

  The first Asian Adam and Eve clans

  As we saw above, a small number of founding Eve clans from Africa landed in the Yemen and became isolated from Africa. After many generations these lines eventually drifted down to just one mitochondrial Out-of-Africa Eve, otherwise known by the rather dull technical label L3. L3 soon gave rise to just two daughter female clans: Nasreen (N), and a sister clan, Manju (M) (see Figure 1.4).

  Manju’s most ancient and diverse family is found in India, and Nasreen, for her part, was the only mother for Europeans – there being virtually no daughters of Manju in West Eurasia. Both Nasreen and Manju’s descendants are now, however, found in every other part of the world except West Eurasia (see Appendix 1 and Figure 0.3). This fact on its own confirms that every non-African in Australia, America, Siberia, Iceland, Europe, China, and India can trace their genetic inheritance back to just one line coming out of Africa: it confirms that there was only one exodus. After the exodus, it seems, L3’s own unique African identity went the way of genetic drift and was lost except for a few local remnants, leaving just Nasreen and Manju and their daughters. We can thus trace every modern non-African descendant waiting at a shop counter in, say, Outer Mongolia, Alice Springs, or Chicago, back to that first out-of-Africa group.

  There are a couple of exceptions that prove the rule. One of these is U6 (already mentioned), who moved back from the Levant into North Africa. The other is M1, who moved back across the Red Sea into Ethiopia about the time of the last ice age. How do we know that? Some exciting recent work by Estonian geneticists Toomas Kivisild and Richard Villems has showed that M1 does not go back as far in Africa as does the Manju clan in Asia.44 In other words, M1 was a more recent recolonization of East Africa back from Asia.

  Eve’s daughter line Manju is found only in Asians, not in Europeans. When we look at the oldest Manju branches in Asia we find a date of 74,000 years for the Manju clan in Central Asia, 75,000 years in New Guinea, and 68,000 years in Australia. India, as I have said, has the greatest variety of Manju sub-branches and may even have been the birthplace of Manju from L3; one Indian subclan alone (M2) has a local age of 73,000 years.45

  When we look at the genetic trail of our fathers, written in the Y chromosome, we see a similar picture. Of all the African male lines present before the exodus, only one gave rise to all non-African male lines or clans. This ‘Out-of-Africa Adam’ line gave rise to three male primary branches outside Africa, in contrast to the two female ones (Nasreen and Manju). Known to geneticists as C, D/E (or YAP), and F, I have chosen for simplicity to call these three clans Cain, Abel, and Seth after Adam’s three sons (see Appendix 2). As with Out-of-Africa Eve’s line, there are also modern day sub-Saharan African representatives. In Adam’s case this is Abel’s line, which has both an Asian and an African/West-Eurasian branch. The latter has a high representation, particularly in Bantu peoples, who recently and dramatically expanded from the north to the south of Africa. To keep things simple at this stage, however, I will leave more detailed discussion of Adam’s three sons to Chapters 3–7.

  The origins of Europeans

  The genetic tree tells us something clear and quite extraordinary about Europeans and Levantines: they came, not directly from Africa, but from somewhere near India in the south. Their matriarch, Nasreen, was probably the more westerly of Eve’s two Asian daughters to be born along the coastal trail. She is different from Manju in that her daughters are found among non-Africans throughout the world, in Eurasia, Australia, and the Americas. This difference from the Manju clan, which is absent from Europe and the Levant, means that the separation of Nasreen into Easterners and Westerners could have happened near where the beachcombers reached India. By genetic dating, Nasreen’s Asian and Australian descendants are at least as old as Manju.46 The most likely point on the route for the birth of Nasreen is the Arabian Gulf. At that dry time it was not a gulf at all, but an oasis of shallow freshwater lakes fed by underground aquifers and the Tigris and Euphrates rivers. There in the south, Nasreen had a daughter, Rohani, 60,000 or more years ago. This beautiful desert refuge must have survived throughout the following tens of thousands of years, for, although these western clans clearly originate in the south, we find no genetic or archaeological evidence of Nasreen’s and Rohani’s daughters having arrived in Europe or the Levant until 45,000–50,000 years ago.

  As always, there is a climatic reason for the late colonization of Europe by Nasreen’s daughters from the Gulf region, and we can find it in cores drilled from the seabed off the Indian coast, in the submarine delta of the Indus. As explained above, access between Syria and the Indian Ocean was always blocked by desert during glaciations. Almost exactly 50,000 years ago, however, there was a brief but intense warming and greening of South Asia, with monsoon conditions better than today. This climatic improvement can be detected as a carbon-rich layer in the undersea delta of the Indus.47 Since the warm spell lasted perhaps only a few thousand years, geologists call it an ‘interstadial’ rather than ‘interglacial’, but the effect on the dormant Fertile Crescent of Iraq was the same.

  For a short while that narrow green corridor opened (Figure 1.8), allowing migration from the Arabian Gulf to Syria, and the great-granddaughters of Asian Eve went north-west up the Fertile Crescent to the Levant (see Chapter 3). The original South Asian source for these European migrants is revealed by the genetic trail: as can be seen from the genetic tree (see Figure 1.4), for each Nasreen branch that went north-west to Europe, another Nasreen branch went east to India.

  Figure 1.8 The Fertile Crescent corridor to Europe. Around 50,000 years ago, weather warmed and moistened sufficiently to open a green corridor (dotted lines) across the desert between South Asia and Turkey. For the first time since the interglacial 75,000 year
s before, modern humans were able to move into the Levant and then to Europe.

  Such a picture of Europeans’ genetic roots in South Asia overturns the northern out-of-Africa theory. It also fundamentally changes the Eurocentric view of Europeans as the first fully modern human culture outside Africa. So, to be safe, we must ask whether there is any archaeological evidence to contradict the idea of the first Europeans coming from South Asia. There does not appear to be any – rather, it seems to be the other way round.

  The earliest archaeological evidence in West Eurasia for technology of the Upper Palaeolithic is no more than 47,000 years old. The Belgian archaeologist Marcel Otte challenges the conventional view of Europeans’ ancestors having come out of North Africa, developing their Upper Palaeolithic technology en route, and points instead to the Zagros Mountain range in the present-day ethnic region of Kurdistan, just north of the Gulf, which he argues was the core region for Upper Palaeolithic technology.48

  Sri Lanka, then a peninsula to the south of India, is extraordinary in that it turns the east–west cultural tables. Reliable evidence gives a date of 28,000 years ago for manufacture of microliths on Sri Lanka. These tiny, specialist stone blades did not appear in Europe and the Levant until 10,000 years ago. Indeed, in a tantalizing find, one level below those microliths, another more basic microlith layer has been dated to between 64,000 and 74,000 years ago. If the date of this find is confirmed, then it could be the smoking gun of the trail out of Africa around 70,000 years ago.49

  Summary

  Archaeological and anthropological controversies over our ultimate origins as the latest human species could be resolved by the unbroken genetic trail of our Eve line back to the first modern Africans. The genetic evidence has allowed us to focus this perspective down to the precise movements of our immediate ancestors. As a result, we can see only one group of people coming out of Africa over 70,000 years ago. This fundamental departure from the conventional view of multiple movements out of Africa fixes all subsequent migration routes for the rest of human history, starting from that single southern trail. The first out-of-Africa pioneers moved along the Arabian coast to the Arabian Gulf, where they founded the first colony of Westerners, who would colonize Europe much later. The journey from India onwards to the East has another history.

  2

  WHEN DID WE BECOME MODERN?

  THE PAROCHIAL OBSESSION OF EUROPEANS with their past and with their apparent supremacy in Palaeolithic material culture led, in the last century, to a number of presumptions. Roughly speaking, these were that we (for I am European) were the first to think symbolically and in the abstract, and the first to speak, paint, carve, dress, weave, and exchange goods.

  In Chapter 1, I suggested that the false assumption that these skills were unavailable to our African forebears paralleled the conviction that Levantines and Europeans arose from a northern move out of Africa separate from those that gave rise to Australians and Asians. This view is undermined if we accept the evidence that European and other Western genetic lines arose as early offshoots of a single South Asian family group that spawned the whole non-African world. In this chapter I argue that the desire to make a centrepiece of the ‘coming of age’ of modern humans in Europe and the Levant obscured other, valid views of the prehistory of both the East and the West.

  The genetic evidence that modern humans emerged from Africa, leaving behind them ‘homeland’ representatives whose descendants still live in Africa and are self-evidently ‘fully modern’ in every way, has disturbing implications for continuing Western perceptions of modern Africans. Although the danger of these views is obvious, the mindset of some European archaeologists has remained unchanged.

  Out-of-Africa versus the multiregionalists

  Archaeologists have continued to argue that a number of innate and fundamental human behaviours sharply distinguished the first modern Europeans from their close European cousins, the Neanderthals, and also, following a similar line of argument, from their immediate ancestors in Africa. One reason for emphasizing this contrast may have been to counter the multiregional hypothesis of human origins and prove that we were not descended from Neanderthals. Implicit in these arguments, however, is the assumption not only that early modern Europeans (the Cro-Magnons) were the first to develop and transmit these new skills to succeeding generations, but that the Neanderthals were somehow biologically not up to it. Extending that type of argument would suggest that the Cro-Magnons’ anatomically modern ancestors in Africa were not sharp enough to create Upper Palaeolithic technology either. In other words, the Europeans were the first to speak, paint, and carve, and then, we have to assume, they somehow later taught the Africans and Australian aboriginals (not to mention Asians) how to do it. Now, I may have misunderstood what I have read, but this is the message I get even from some recent publications. Before examining the external evidence against this Eurocentric view, I will look at what could have given rise to such a distorted picture.

  The problem began in 1856 with the first discovery of a Neanderthal skull. Right from the start, Neanderthals were given a bad press, being ridiculed as beetle-browed idiots. This image was defined in 1921 in a short story, ‘The Grisly Folk’, offered by popular science writer H.G. Wells, who presented them, in contrast to the modern and articulate Cro-Magnons, as grunting, hunched monsters. Attempts to rehabilitate Neanderthals as our potential equals and cousins never quite succeeded, because even their apologists consistently damned them with faint praise, and film documentaries continued to stress their physical appearance and overlook their large brains.

  The truth is that we still all regard the Neanderthals as lesser folk, and experts continue to emphasize perceived cultural differences. When we place their material culture alongside that of their contemporaries, the first modern Europeans, our prejudice seems to be confirmed. The moderns painted cave walls, and even themselves – no indication that Neanderthals did that. The moderns worked non-stone objects such as bone, shell, and antler, and carved figurines – something it was previously thought no Neanderthal could be caught doing. Such artefacts moved hundreds of kilometres across Europe, indicating some kind of trade or exchange – initially, no evidence for that among Neanderthals. How could there be? Neanderthals were not even using these materials. Such long-distance cooperation appeared to complement other evidence which has been used to argue that moderns had larger and more complex social networks than Neanderthals. They, in contrast, have been portrayed as living inflexibly in small groups, lacking the intellectual wherewithal to adapt to changing circumstances – although Clive Gamble points out that exotic high-grade raw stone for knapping had, in fact, been moved up to 300 km (200 miles) around Europe before the Upper Palaeolithic.1 The moderns made hearths and buried their dead – not a typical feature of Neanderthal culture. Finally, when we look at that most abundant and durable message from the past, stone tools, we find a clear and convenient difference between Neanderthals and moderns. The latter were making blades – slivers struck from a stone core that were more than twice as long as they were broad.

  Cro-Magnons, the first European moderns, appeared on all these counts to be the ‘all-singing, all-dancing’ people when compared with the dull, brutish, inflexible Neanderthals – so why? The standard answer has always been that we must have been biologically superior, at least as far as our brains were concerned. The Neanderthals’ acknowledged superiority in physical strength, and their thick bones, contrasting with our own thin skeletons, completed the picture of brawn versus brain. The degree of contrast in these cultural differences between the two groups of humans has been used to further enhance the case for a biological coming of age of modern Europeans as sentient beings, but there is little logic in this argument.

  What else about our cousins could we speculate on? Among the perceived differences that elevated man from beast are abstract and symbolic thought – and yes, speech. Could we establish that Neanderthals were ‘without speech’ – in other words, ‘dumb’? T
he fact that they had a very similar ‘bone of speech’ (the hyoid) in their voice box which is very similar to the hyoid in moderns has not stopped such speculation. There is even a common opinion that all the new skills demonstrated by modern Europeans, including the development of speech, resulted from a special gene or genes that kicked in 40,000–50,000 years ago (see the Prologue).

  The first and indeed most of the spectacular discoveries of early modern human creativity (Upper Palaeolithic art and technology from roughly 18,000–35,000 years ago) were made in Europe. That is, after all, where archaeology started and where, for the past 150 years, most archaeologists have come from. We are all familiar with the extraordinary grace, realism, and perception revealed in the cave paintings of Lascaux and Chauvet in southern France (see Plate 9). It seems an almost unconscious extension of wondering about the artistic explosion of the European later stone age (also known as the European Upper Palaeolithic) to see this as marking modern humans’ coming of age. Some put this thought into plain words and argue that, before this time, ‘Anatomically Modern Humans’, whose remains date back in Africa to at least 160,000 years ago, may have looked modern but had not quite ‘got there’ yet.2

  If modern Europeans were emerging from the chrysalis with such a spectacular unfolding of genius, the extreme argument continues, then surely there must have been some biological (i.e. genetically determined) element which before then had been wanting in our make-up. However, this line of argument seems, dangerously, to conclude that the ancestors of modern Africans and modern Australians would have been biologically less advanced than those of Europeans.