When I first became interested in human origins, I had a vague idea that some of us left Africa around 50,000 years ago and settled the world, after which we remained more or less in place until the empire-building of Mesopotamia, Egypt and Rome, then slavery and colonialism, mixed things up. I’d also assumed there was a one-way flow, and that Europeans gradually evolved to have lighter skins because of the cold.
I soon discovered each of these premises was flawed. For one thing, modern humans were making sorties out of Africa for more than 130,000 years before they settled in Europe, and they never stopped moving, both within Africa and beyond. The current geographical spread of humanity bears little resemblance to that of pre-agricultural times. There were huge population movements throughout Europe, and similar processes in Africa, with one group replacing another, wiping them out or simply absorbing them through the sexual dominance of the invading males. Better-armed herders, with rigidly patriarchal structures, replaced more egalitarian hunter-gatherer and farming cultures. I also discovered that while the evolution of lighter skin, hair and eyes had something to do with the cold, it was far more complex than I’d previously assumed, and that the genetic roots for light skin came from Africa.
People, like animals, migrate because they run out of space. They need room to hunt and gather or to herd and farm, so whenever there’s a population spike some need to move. There are other reasons, such as climatic change and conflict with rival groups, but migration has nothing to do with intelligence. Like our evolutionary predecessors, we Homo sapiens have migrated right from the start: out of Africa, around the world and back again.
Evidence of the scope of these early migrations is mounting. Finds of human-made stone tools suggest migrations via the Nile Valley into what is now Israel and the United Arab Emirates about 125,000 years ago. More significantly, a modern human jawbone and teeth found in a cave in Israel were between 177,000 and 194,000 years old; at least 50,000 years older than any previous out-of-Africa discovery. Adding to the recent hoard, in 2016 a fossilised finger bone, dated at 85,000 years old, was found in Saudi Arabia, while forty-seven modern human teeth, found in a cave in southern China, were dated at between 80,000 and 125,000 years old based on the stalagmites in that part of the cave.
What happened to these early out-of-Africa migrants? Perhaps it is not surprising that these small groups didn’t take root for long, given the kind of challenges they faced finding food and shelter and protecting themselves from animal predators that included packs of sabre-toothed tigers. Many were wiped out by the Toba (in Sumatra, Indonesia) volcanic eruption 75,000 years ago, which caused a volcanic winter for between six and ten years and prompted a sharp human population decline; five thousand years later the total human population had been reduced to a few thousand.
We now know that others were out-hustled by Neanderthals, refuting the belief that human-Neanderthal conflicts always went one way. A group of humans reached the Levant around 80,000 years ago and ran into the Neanderthals. It appears from the archaeological evidence that while the Neanderthals survived, the humans either didn’t, or they retreated. This does not necessarily mean that the Neanderthals were driving the humans off or killing them. Maria Martinon-Torres, a University College London anthropologist who was part of the team that made the discovery, said there was no evidence of physical confrontation. ‘It was a matter of who was best able to exploit resources,’ she said. ‘I think we underestimated them. They were not grunting, ignorant cavemen. They were our equals.’1
Around 70 to 75,000 years ago another group left Africa and moved down the southern coastline of Asia, in the direction of South-East Asia and Oceania. This lot left a genetic imprint on modern humans. Some found their way to China, and much later to Japan and Korea. At least 65,000 years ago others reached Australia, at one point crossing 250 kilometres of open water in ocean-going boats or rafts. It was previously assumed they settled about 45,000 years ago (Yuval Noah Harari uses this date2) but their arrival has been pushed back by discoveries in Madjedbebe of surprisingly sophisticated axes, spear tips and seed-grinding tools, as well as huge quantities of ground ochre, dated at 65,000 years old.
It is said that Australian Aboriginals have the oldest continuous culture in the world but this is not quite accurate. For one thing, the San (Bushman) people of Southern Africa have an even older lineage. For another, it is off the mark to talk of a single, continuous Aboriginal culture. There were at least 250 Aboriginal languages, each belonging to a different ‘nation’, when the Europeans arrived. But the most common misconception is that the native Australians were a backward people, perhaps even a different branch of humanity. In the nineteenth century, it was widely believed that the biological gap between Europeans and Tasmanians was so wide that if they bred, they would produce infertile offspring (‘mulism’). The Tasmanians were wiped out, due to European diseases and the genocidal policies of the British, but their genes continue to flow down the generations because of the number of mixed-race British-Tasmanians who survived.
Racist perceptions of native Australians persisted into the second half of the twentieth century. In 1962, the then president of the American Association of Physical Anthropologists, Carleton Coon (a rather unfortunate name for a racist), asked:
If all races had a recent common origin, how does it happen that some peoples, like Tasmanians and many of the Australian aborigines, were still living in the nineteenth century in a manner of Europeans of over 100,000 years ago? [A reminder: Europeans of 100,000 years ago were Neanderthals, not humans] Either the common ancestors of Tasmanians-cum-Australians and that of the Europeans parted company in remote Pleistocene antiquity or else the Australians and Tasmanians have done some rapid cultural backsliding, which archaeological evidence disproves.
Coon was saying that the native Australians had always been backward, and remained so. In his bid to show they were mentally inferior to whites, he measured cranial capacity and the inclination of the jawbone and decided they were ‘still in the act of sloughing off some of the genetic traits which distinguish Homo erectus from Homo sapiens’.3 He conceded that some evolution had taken place ‘but as one would expect in a marginal area of the southern hemisphere, its overall rate cannot have been rapid.’4
Coon was writing in an era when Australian Aboriginals did not yet have the same franchise as whites; that did not happen until 1967. It was only in the early 1970s that the forced adoption of mixed-race Aboriginal children – a eugenic policy launched in 1909 – ended. Even as late as 1974, this perspective had not vanished from ‘respectable’ Western academia. The Oxford biologist John R. Baker wrote that the skulls of ‘Australids’ carried the imprint of primitiveness, adding that they ‘may serve as a reminder of a stage in the evolution of more advanced forms’.5 Hardly surprisingly, Baker’s book Race was endorsed by the neo-fascist British National Party. After Carleton Coon’s death in 1981, it emerged that he had given covert backing to the US segregationist cause.6
Since the 1970s an impressive flow of data has emerged showing that the culture of these early immigrants to Australia was more complex and technologically innovative than previously thought. As well as evidence that they arrived by island-hopping using boats or rafts, which must have involved planning, navigation and technological innovation, their prehistorical cultural range can be surmised from cave art and artefacts discovered over the last decade. A few examples: finely drawn charcoal lines portraying a moving figure, dated at 28,000 years ago; a 35,000-year-old edge-ground axe of a kind that only emerged thousands of years later in other parts of the world; a red ochre painting portraying two emu-type birds with long necks (while dating of ochre is tricky, they’ve since been identified as a giant bird species that became extinct at least 40,000 years ago).
Another wave of migration from Africa, which probably started nearly 60,000 years ago, took humans (known today as Cro-Magnons) across the Sinai Peninsula, throughout Asia and then, about 43,000 years ago, to Europe. There they coexisted with Neanderthals for around 4,000 years and, as we’ve seen, bred with them on a limited scale early in their migration, leaving a lasting genetic imprint. When resources were scarce, it seems they possibly killed Neanderthals in skirmishes, and ate them; there is evidence of Neanderthal bones that have been cut and scraped with Cro-Magnon blade tools, which strongly suggests cannibalism. Some writers have suggested this was an early example of genocide but there is scant evidence for this. The Neanderthals were already in sharp decline when the out-of-Africa humans arrived. It may be that they were killed off by a combination of inbreeding and new diseases for which the Neanderthals had no immunity, or perhaps it had more to do with competition for game and hunting grounds.
The Neanderthals, who lived in Europe, the Middle East and Asia for 400,000 years, weren’t the subhuman oafs of popular mythology. They had larger skulls and brains than modern humans and although bigger brains aren’t necessarily an indication of greater cognitive potential, aspects of their archaeological record, including the occasional use of pigments and body ornaments, show they were at least capable of imitating the human migrants; and recent finds suggest this was probably more than mere imitation. Three cave paintings in Spain (red motifs and hand stencils) have been dated at between 64,000 and 68,000 years old.7 This dating – from more than 20,000 years before the Cro-Magnons’ arrival – makes it clear the painters were Neanderthal. Genetic analysis shows they had the FOXP2 gene, which is associated with language, while recent computer modelling of their hyoid bone (in the neck) indicates they were capable of speech.8 Given that Homo sapiens interbred with them, it seems likely that there was some form of communication between the two groups. They also cared for their sick and elderly, buried their dead and made stone tools similar to those of the Cro-Magnons, using techniques that demanded skills, dexterity and planning.
However, some question this contemporary picture of Neanderthals as our intellectual equals. The Cro-Magnon expert Ian Tattersall points to a lack of evidence of systematic symbolic activity among Neanderthals. ‘[S]ymbolism is highly unlikely to have been a routine or important factor in the Neanderthals’ existences,’ he notes, comparing them to the new arrivals from Africa who ‘led lives that were drenched in symbol’ and had ‘acquired a fully modern sensibility’ before they left Africa.9
One view is that the Neanderthals, who survived in Europe for so long, lacked the versatility and cunning to cope with the out-of-Africa immigrants, and also their dexterity. The Cro-Magnons brought from Africa the ability to sew, which would have allowed them to keep warm while hunting in the winter. They had an additional advantage in competing for scarce resources; their lighter bodies meant they were more mobile and required less food. They may also have had more sophisticated organisation and planning. Whatever the reasons, the human population replaced the already-declining Neanderthal population within about four thousand years of arriving in Europe.
The sad death of the last Neanderthal, around 39,000 years ago, was soon followed by the take-off of Cro-Magnon artistic expression: sculptured figurines, musical instruments and an impressive variety of rock paintings of animals and humans. The detail, scale and variety of these artistic forms has led some to conclude that this was the period in which the truly modern human brain kicked in. But as we saw in the last chapter, this view has also been discredited from the abundant evidence of far earlier artistic expression in Africa.
Agriculture and animal husbandry began more than 11,000 years ago but there are examples of crop growing in Africa, such as planned burning of the land to encourage corn growth and the use of tools to process corn, tens of thousands of years earlier. And hunter-gatherers were not all ‘cave men’. Long before sustained agriculture took off, at least 13,000 years ago, some communities lived in larger village-type groups. In a few areas, they were also involved with more organised forms of religious practice, including building ‘cult of the dead’ monuments.
The most remarkable of these is the Göbekli Tepe in south-eastern Anatolia (Asian Turkey), a fifteen-metre structure built of stone, containing two hundred huge T-shaped pillars, some adorned with carvings of animals. The archaeologists excavating the site believe it functioned as a spiritual centre more than 13,000 years ago. Its most decorated part, which is three hundred metres in diameter, has been dated at 11,600 years old and its final layer was completed 10,000 years ago, which means its origins predate the Great Pyramid’s by 7,000 years. They also estimate that carrying the pillars (which weigh up to twenty tonnes) from nearby quarries would have involved five hundred people, who would have to have been organised and fed. And yet there’s no sign of sustained settlement. In other words, the people who built it were hunter-gatherers, or lived a predominantly hunter-gatherer lifestyle. It would seem that, at least in Anatolia, monumental building projects preceded agriculture and urban living by thousands of years. As the head archaeologist Klaus Schmidt put it: ‘First came the temple, then the city.’10
Among the first to move from hunting and gathering to agriculture were indeed the Anatolians, along with those living in the Fertile Crescent of western Asia and Egypt, and also India. They, in turn, were followed by Mesopotamia, parts of China, Mexico, Syria, the Jordan Valley, New Guinea, Andean South America and the Sahel region of Africa, which includes Nubia. There are a number of theories about why this change happened but most experts agree there is more than one explanation, including climate change (hot, dry seasons encouraging annual plants that die off and leave seeds and bulbs), the specific weather and soil conditions in these regions, the seeds available there and the presence of animals that were relatively easy to domesticate.
But some, or all, of these factors were present in parts of the world for 95 per cent of human history without a sustained shift to agriculture. In other words, none are enough to explain why people like us lived for 300,000 years as hunter-gatherers and then, within a few thousand years, adopted agricultural lifestyles. Explanations must therefore include factors in these communities. Some may have been idiosyncratic but when looking for a general cause, population pressure is an obvious candidate. Hunter-gatherer lifestyles are hard to sustain once the population reaches a level where there are not enough edible plants or animals to feed the growing community. The search for new food sources prompted migration all over the world but eventually the most desirable areas would have faced population growth if counter-pressures (disease, wild animals, climate change, fighting) weren’t enough to keep it down. Overpopulation might have provided the impetus to cultivate plants and herd animals to supplement hunting and gathering, until it became the main source of sustenance. Farming and herding in turn prompted the development of larger, more settled and more stratified communities and the necessity for more trading.
And so, the first urban societies emerged about 7,000 years ago in several areas of the world. This in turn nudged some communities to begin recording transactions. Writing for the record emerged, using clay tokens or beads on a string for counting, followed by numbers and proto-writing (picture writing systems) which eventually progressed to the writing of language in Mesopotamia 5,200 years ago, leading to cuneiform, a representation of the Sumerian language, a few hundred years later. This was followed by other forms of writing in several parts of the region, including hieroglyphics in Egypt (influenced by cuneiform), and independently in India/Pakistan, China and Turkmenistan, and among the Olmecs in Mexico and the Mayans in Guatemala. The Nubians were the first black Africans to use writing, about 2,500 years ago; initially the hieroglyphics of their Egyptian neighbours and later their own alphabet for their Meroitic language.
Peruse sub-Saharan African history and prehistory and you’ll see a story of one population replacing or absorbing another. The ‘first people’ of Southern Africa, the San (Bushmen), had the region all to themselves for tens of thousands of years. Then, a little more than 2,000 years ago, they were joined by their close genetic cousins, the Botswana-based Khoekhoe, who’d made the switch to a pastoral, cattle-herding, hut-living lifestyle. These two together are now known as the Khoesan. Around 1,800 years ago the first Iron Age Bantu-speaking farmers arrived, having gradually moved south from what is now Nigeria and the Cameroon in search of more verdant farmlands (they also moved in the direction of East Africa). In South Africa, there is evidence of cooperation and interbreeding, and also of conflict over land as the farmers’ numbers increased, which inevitably led to the Khoesans’ demise as they were eliminated from large tracts of the country.
When the Europeans arrived in the seventeenth century they wiped out the Khoekhoe people, mainly by passing on European diseases. The remaining San were hunted down and confined to the Kalahari Desert and remote parts of Botswana, Namibia, Zimbabwe and Angola. The Europeans then trekked north, using their guns to subjugate the Iron Age, Bantu-speaking farmers. By then, the admixture of these groups and of Malayan slaves had created the mixed-race ‘Coloured’ population, which today numbers more than five million. A 2010 genetic study of ‘Cape Coloureds’ (the largest ‘Coloured’ population) showed that their ancestry was Khoesan (32–43%), Bantu (20–36%), European (21–28%) and South/South-East Asian (9–11%). Examination of the maternal mitochondrial line showed that the majority of the maternal line was Khoesan, while the analysis of the Y chromosome showed the male line was mostly European or European-African.11
A similar process happened earlier in Eurasia, with agricultural migrants devastating, often replacing, the hunter-gatherer communities. The result, as the Harvard geneticist David Reich put it, was that ‘the people who live in a particular place today almost never exclusively descend from the people who lived in the same place far in the past.’12 Reich shows that modern Europeans did not descend primarily from hunter-gatherers from their countries or regions but from different populations of agriculturalists, starting with one lot who migrated from Anatolia and another lot (who themselves were a mixture of Iranian farmers and Eastern European hunter-gatherers) that later moved from the steppe north of the Black and Caspian seas. The latter group replaced existing populations of hunter-gatherers and farmers, possibly by spreading air-borne pneumonic plague, to which steppe people had greater immunity. Throughout Western Europe, farmers squeezed hunter-gatherers to the fringes but the farmers were themselves largely replaced by these newcomers. From a different angle, just over 5,000 years ago the ancestors of ‘native’ northern Europeans had not yet made their appearance.13
The Iberian Bell Beaker strand of the steppe people (named because of their distinctive form of pottery) arrived in Britain 4,500 years ago and largely replaced the Stonehenge-building farmers who had arrived via Anatolia about 6,000 years ago (and had themselves edged out the existing hunter-gatherer population). Over time there were further waves of immigrants, some more peaceful than others. The Celts began arriving about 4,000 years ago, followed by the Angles and Saxons (from 1,600 years ago), then the Vikings (1,200 years ago) and Normans (from 1066 CE). Yet all these people shared a common genetic past, much of it drawn from the herders who migrated from the Russian steppe 5,000 years ago. In fact, many of those who followed over the next 900-plus years – including European Jews, French Huguenots, Dutch, Italians and those from the Indian subcontinent – shared substantially similar genetic heritages.
Some discoveries from full genome analysis of ancient DNA rub against nationalist sentiments. One example relates to the Nazi belief that the origins of the Germanic people and languages lay exclusively in the Corded Ware culture, which had deep roots in the German domain. Now, however, DNA analysis shows that the genetic origins of this culture lay in the Russian steppe, with its ancestry drawn from an Iranian population and Eastern European hunter-gatherers,14 which would not have pleased Hitler. Likewise, some Hindu nationalists in India believed there had been no significant contribution to Indian culture from beyond South Asia. DNA analysis shows this is a fallacy; about half the ancestry of contemporary Indians is drawn from various migration waves from Anatolia, Iran and the Eurasian steppe over the past 9,000 years.15
DNA analysis and archaeological research can also prick religious bubbles, including those of the Abrahamic religions. Israeli archaeologists have long chipped away at the notion of their scriptures as history. One book, The Bible Unearthed,16 written by the archaeologists Israel Finkelstein and Neil Asher Silberman, had a devastating impact on fundamentalist interpretations, showing there was no evidence that the Jewish people were enslaved in Egypt, of the subsequent exodus or the existence of Moses and Joshua. The Bible tells of God’s command to the Israelites: ‘You shall not leave alive anything that breathes’ and shows how Joshua’s men did just this in what, in today’s language, amounts to large-scale ethnic cleansing. The picture presented is of the total slaughter of Canaanite men, women and children and their replacement by the Israelites. Finkelstein and Silberman point to the lack of evidence of any such conquest and the compelling evidence that the emerging Israelite population had never left the area in the first place. This has been reinforced by recent genetic research comparing full genome analysis of five 3,700-year-old Canaanites with that of contemporary Lebanese people. It reveals that the Canaanites not only survived, but flourished, and that their DNA is today found among their Lebanese descendants.17
As the son of an Ashkenazi Jewish father, I was particularly interested in the genetic origins of European Jewry. I will go into more detail on this question but in short it relates to a key argument made by those claiming Ashkenazim are innately of superior intelligence: that they were genetically isolated. DNA analysis has shown the opposite. A major genetic study of mitochondrial DNA (the maternal line) found that European women, not women from the Levant (Middle East), were the main female founders of the Ashkenazi population.18 ‘These results point to a significant role for the conversion of women in the formation of Ashkenazi communities, often started by male traders,’ the authors note.19 They conclude that 81 per cent of Ashkenazi female ancestry was European, with just 8 per cent from the Levant.20 However, Y chromosome genetic studies suggest that the Middle Eastern contribution to the male line was far more substantial.21
This pattern of the male line showing a stronger connection to the migrating population is repeated over and over. Among Ashkenazim it involved male traders with roots in the Middle East having children with European women, who then converted. In many other cases, conquest was involved, with women among the spoils. One example comes from the horse-riding, Bronze Age Yamnaya herders, who spread from the Russian steppe, displacing both the hunter-gatherers of Central Asia and the farmers of northern Europe, and introducing a far more patriarchal, militaristic and wealth-divided society.22 The skeletons beneath the burial mounds they left behind show battle scars, and they went to their graves with battle axes and daggers. According to the archaeologist Marija Gimbutas, their arrival, starting around 5,000 years ago, marked the decline of the ‘Old Europe’ in which women had played a more central role. Instead, we see a far more male-centred society in which power was concentrated in small coteries of elite men, who spread their genes vigorously.23
Similarly, when Genghis Khan established his thirteenth- and fourteenth-century Mongol empire, which spread from China to the Caspian Sea, he and his small number of military leaders left a significant impact on the genomes of billions of people currently living in the lands he conquered. A Y-chromosome study by the geneticist Christopher Tyler-Smith and his team suggests that around 8 per cent of males living there in the region show genetic markers of one male from Mongol times; possibly Genghis Khan himself.24
This pattern is repeated wherever conquest, colonisation and slavery prevailed. DNA analysis of contemporary African-American populations suggests the genetic contribution of European-American men is four times that of European-American women,25 and it would have been higher in the slave era because of the routine rape of slave women by slave owners and their sons, or the use of slave women as concubines. One example comes from the slave-owning Thomas Jefferson’s ‘mistress’, Sally Hemings. She had three white grandparents but because her mother was a slave, so was she. Hemings, who was thirty years younger than America’s third president, might have been as young as fourteen when she started her relationship with him; she went on to have six of his children.26
It is often thought that the flow of African-related migration went one way, outwards, but genetic analysis shows there was significant traffic in both directions. This is most obvious in North Africa, where lighter skins and European-like facial features are commonplace. Studies of North African genomes confirm this, suggesting substantial backward migration from the Middle and Near East and from Eurasia starting 30,000 years ago, with a major gene flow 12,000 years ago, and several since.27
Less widely known is that East Africans also carry significant proportions of Eurasian DNA. Farmers living in what is now Jordan and Israel spread into present-day Ethiopia and other parts of East Africa. Analysis of the full genome of a 4,500-year-old man found in the Mota Cave in Ethiopia helped scientists to understand the genetic changes in the population in that area. They discovered a large-scale genetic flow from the Middle East to East Africa around 3,000 years ago, leaving a far bigger Eurasian-origin genetic mark than previously recognised. ‘Roughly speaking, the wave of West Eurasian migration back into the Horn of Africa could have been as much as 30 per cent of the population that already lived there – and that, to me, is mind-blowing,’ the senior author of the study, Dr Andrea Manica, from the University of Cambridge’s Department of Zoology, said. ‘The question is: what got them moving all of a sudden?’28
While the East African story is interesting, Manica’s study exaggerated the impact of this reverse migration on African populations beyond East Africa, as a result of what he described as ‘software incompatibility’ errors. Pontus Skoglund, a Harvard population geneticist who re-examined the genome data, commented: ‘Almost all of us agree there was some back-to-Africa gene flow and it was a pretty big migration into East Africa but it did not reach West and Central Africa, at least not in a detectable way.’29 One legacy of the migration from the Middle East into East Africa was a ‘European’ gene, SLC24A5, associated with lighter skin. This is prevalent in Ethiopia and Tanzania but it does not seem to lighten skin colour there to the same extent as in Europe.30
Recent research involving full genome DNA sequencing shows how mixed we all are genetically. For all human existence, populations have replaced each other, absorbed each other and blended with each other. Whenever populations come into contact, they end up having sex, often not consensually. Very few populations are anything other than genetic mixes, and most of that mixing has taken place within the last 10,000 years. This applies as much to Europe as it does to Africa. As we shall see in Chapter 6, bearing this in mind, skin colour takes on its appropriate proportions as a minor genetic detail.