Homo Britannicus

by Chris Stringer

  thousand miles across Doggerland to the east the bodies of three people in their late teens were buried in mysterious circumstances at what is now the village of Dolní Vĕstonice in the Czech Republic. The oldest of the three, and the first laid in the grave, was in the centre, and suffered from severe growth abnormalities that deformed the backbone, hip bones and the legs, so much so that determining sex (which can usually be done reliably from the pelvis) is difficult. On the right was a large and robust male, lying face down, with the head turned away. His left arm covered the hand of the disabled individual in the middle, as if holding it. On the left was a smaller robust male lying on his left side and facing the individual in the middle, with both his arms reaching down to the pelvic region of the central individual.

  The three skulls and the surrounding soil were impregnated with red ochre and there were rich head coverings of wolf and fox teeth and ivory beads. The central individual also had considerable quantities of ochre under the pelvis and between the legs. Further clues to the significance of the triple burial may come from a wooden stake apparently pushed into the body of the male on the left, and the fact that the male on the right might have had a smashed skull. Many different theories have been advanced to explain this strange burial pattern including murder, sacrifice, failed childbirth, and heterosexual or homosexual liaisons, and the burial has even featured in the novels of Jean Auel. A little later and even further east, two children and a man were buried at Sunghir in Russia, accompanied by thousands of mammoth ivory beads (probably sewn on clothing), hundreds of arctic fox teeth pendants, and a huge array of ivory ornaments, tools and weapons. These burials contained items that had taken days, weeks or even months of preparation, and were carrying important social messages that we cannot read now. They indicate that Cro-Magnon society was already complex and stratified in terms of roles and social status.

  We get the same message of complexity from the cave art and sculpture that the Cro-Magnons left behind them. Remote parts of caves that were never lived in are sometimes almost saturated with red or black images of the animals that the artists saw in the outside world or in their imaginations – horse, mammoth, woolly rhino, bison, aurochs, deer, reindeer, and more rarely carnivores such as lion, bear, hyaena, and humans themselves. Rarer still there are birds, strange symbols, and weird figures that are part animal, part human. This tradition of cave art lasted over 20,000 years, and it was probably produced for many different reasons, but some of it certainly seems to be linked with spirituality and perhaps ceremonies carried out by torchlight or oil lamplight deep in the caves. There is a parallel tradition of human representation in the form of statuettes, usually female, and often generously proportioned (the so-called Venus statuettes). These figurines may be engraved, or carved from stone, bone, antler or ivory. In some cases (as at Dolní Vĕstonice), they were moulded from a mixture of clay and ash, fired to a temperature high enough (had the Cro-Magnons wanted) to produce the first pottery. The statuettes are not usually found deep in caves but instead are in living sites, which some people have suggested means they had a quite different significance to the cave art, perhaps special to women. As well as the representational art there are also examples of notched or patterned engraved bones, which have been interpreted as tallies, or calendars based on menstrual or lunar cycles (there is a nice example of these from Gough’s Cave in Cheddar Gorge, about 14,000 years old). All of these behaviours seem to have appeared in Europe after the Cro-Magnons arrived, and we have no evidence that the Neanderthals produced anything as complex. But the Neanderthals did bury their dead, with some possible examples of associated objects such as food (perhaps offerings?) or stone slabs; they knew about pigments, even if they did not paint caves; and they clearly had skills with material such as wood that have almost all perished. We need to bear this in mind when evaluating the relative abilities and complexities of the two populations. However, they clearly differed in their reach across the landscape. Whereas virtually all Neanderthal stone tools were made from raw materials sourced within an hour’s walk from their sites, Cro-Magnons were either much more mobile or had exchange networks for resources covering hundreds of miles – for example, amber from the Baltic and shells from the Atlantic or the Mediterranean traversed much of Europe in Cro-Magnon times. This suggests that Neanderthal groups were small, with restricted home ranges, and limited networks of exchange and contact. In contrast, it seems that Cro-Magnon groups were larger and were able to exploit the choicest resources of a region before moving on, establishing and maintaining relationships with neighbouring Cro-Magnon groups as they did so, including networks of trade and kinship.

  As we have seen, the Cro-Magnons first appeared in Europe about 40,000 years ago – but where did they come from? The oldest well-dated early modern fossils in Europe are from the cave site of Oase in the Carpathian Mountains of Romania, a location so remote that it requires diving through a flooded and murky 25-metre tunnel to get to it. The skull of an adolescent and the jawbone of an adult found there are the biggest-toothed of all Cro-Magnons, and there are other features reminiscent of African fossils, as well as a detail in the jaw that is found in Neanderthals. Unfortunately there are no artefacts with the Oase remains, which seem to have been washed to where they were found, but early Upper Palaeolithic artefacts from elsewhere in Europe seem to have dual origins. Some seem to develop out of local precursors and this includes leaf points, such as those found in Britain, and an industry called the Châtelperronian (named after the French cave Châtelperron) that seems to have evolved from the French Mousterian of Acheulian Tradition. The only diagnostic fossils definitely associated with the Châtelperronian are those of Neanderthals. But two other early industries, the Bohunician of eastern Europe, and the Aurignacian, found over most of Europe, seem to be intrusive and have links with artefacts found in western Asia and Africa. While no diagnostic fossils have yet been found with the Bohunician, those with the Aurignacian are modern humans similar to the ones associated with the succeeding widespread European industry – the Gravettian, as found at Paviland.

  The trail of modern human fossils ultimately leads us back to Africa. There are early moderns associated with pre-Upper Palaeolithic tools in Israel, at the cave sites of Skhul and Qafzeh, including the oldest complex burials known. About 100,000 years ago, a child at Qafzeh was buried under deer antlers, and a man at Skhul was buried clasping the jaws of a large wild boar. Beyond these, we only find modern humans and their ancestors in Africa. From sites in Ethiopia (Omo Kibish and Herto), and Kenya (Guomde) there are rather primitive, but essentially modern, human fossils dating from over 150,000 years ago. Just as Europe records the deep roots of the Neanderthals through more ancient fossils such as Swanscombe, Atapuerca’s Sima de los Huesos and Pontnewydd, Africa appears to record the evolution of modern humans through fossils like those from Florisbad (South Africa), Ngaloba (Tanzania) and Jebel Irhoud (Morocco). The two human lines began to

  diverge and go their separate ways over 400,000 years ago, one north of the Mediterranean, the other to the south. Then in the last 100,000 years H. sapiens started to emerge from its African homeland, probably first turning eastwards and expanding along the coasts of Arabia and southern Asia towards China and Australia. Those who settled in western Asia or Arabia may have been the source of the moderns who started to infiltrate Neanderthal strongholds in Europe, or they may have derived directly from a second wave from North Africa. Whether these ancestors of the Cro-Magnons were led towards Europe by a relatively warm phase about 50,000 years ago, and consequent movements of game, or whether pressures such as population growth fuelled their migration, the European Neanderthals were suddenly faced with human competition for the first time in their history.

  We have seen that they, too, were fully human, with brains as large as ours, and they survived successfully through the challenging and changing climates of Europe for hundreds of thousands of years; as we have seen, they descended from people like those at Swansco
mbe and Atapuerca 400,000 years ago. So how close to us were they? They were not our ancestors, but were they just a special ice age race of modern humans, an extension of the degree of difference we can find in H. sapiens across the world today? Thirty years ago, the American anthropologist Bill Howells and I compared skull measurements of Neanderthals with those of early modern humans such as the Cro-Magnons, and with the variation we found between modern people today. In the case of my research, I compared the statistical distance between four regional groups of today – Eskimo, Zulu, Tasmanian and Norse – with those for Neanderthals and Cro-Magnons. While the Cro-Magnons did fit the pattern of being a variant of modern humans, the Neanderthals were far more distinct and just as different from the Cro-Magnons as they were from other modern ‘races’. Howells’ results were very comparable. At the time neither of us went so far as to argue that this showed Neanderthals were different enough to resurrect the species name they were given by William King in 1864 – Homo neanderthalensis – but research since then certainly supports such an idea. In the most wide-ranging of recent studies, the Greek anthropologist Katerina Harvati not only compared the skull shapes of Neanderthals, Cro-Magnons and modern people using sophisticated digital scanning, but added comparisons with a range of skulls from our primate relatives, apes and monkeys. She found that, judging from skull shape, the difference between Neanderthals and modern humans was definitely at the level found today between distinct but closely related species of apes and monkeys.

  We do have another source of data about the past, from living people, and even from fossil ones – DNA (Deoxyribonucleic acid). This is the material that stores the complex blueprints (genes) from which our bodies and the chemicals that run them are created. Our DNA is inherited about equally from both our parents, via combinations of the DNA in the paternal sperm and the maternal egg, but there are exceptions to this. Males inherit a Y-chromosome and its DNA only from their fathers, while we all inherit a special kind of DNA from our mothers – mitochondrial DNA (mtDNA) that derives from separate little structures called mitochondria, the power stations of our cells. Analysing DNA patterns in living people enables us to reconstruct how their DNA has evolved and how they are related to each other, since when DNA is cloned from generation to generation, there are sometimes copying mistakes which, if they persist, can be used as markers to track lines of ancestry and descent. The patterns from modern human mtDNA and Y-chromosome DNA agree in placing our shared ancestry firmly in Africa and in the recent past (less than 200,000 years), in good agreement with the fossil evidence. The rest of the DNA that codes for things like proteins, enzymes and body structure also predominantly shows an African origin, but in some cases there are signs of non-African origins, where a DNA pattern seems to be more ancient in, say, eastern Asia than it is in Africa. We do not yet know whether this indicates a measure of modern human blending with more ancient human lines (such as the Neanderthals) outside of Africa, or whether this is an artefact of limited sampling, which will disappear when larger studies are conducted.

  In the case of mtDNA, a major breakthrough was achieved in 1997 when parts of its pattern were successfully recovered from the original 1856 skeleton from the Neander Valley in Germany, and since then several more Neanderthals have been similarly sequenced. As with the skulls, the mtDNA of Neanderthals is distinct and equidistant from those of modern regional populations, and there is no sign of a closer relationship to recent Europeans, as might have been expected if there had been evolutionary continuity in Europe. The ten Neanderthal fossils that have yielded mtDNA sequences so far reveal differences from each other comparable with those found between modern regional populations, so the Neanderthals seem to have had a population history at least as long and complex as our own. We can calibrate the level of difference between Neanderthals and us, either against our own variation today, or against the differences we show compared with our nearest living relatives, the common chimpanzee and the bonobo. In both cases, the DNA divergence date between us and Neanderthals is estimated at about half a million years, very much in line with a split at the time of Homo heidelbergensis and the subsequent appearance of distinctive Neanderthal features in European fossils such as Swanscombe and Atapuerca (Pit of the Bones) dated to about 400,000 years ago. But is that level of divergence enough to denote a species separation? That is not so clear, since some closely related mammal species show that level of DNA difference, while in others (such as the common chimpanzee) such a level of differentiation is contained within a single species. So Neanderthals are in that grey area, either a closely related sister species (as the fossils indicate), or a very divergent lineage of our own species (as the mitochondrial DNA might suggest).

  And what about contact and possible interbreeding between Neanderthals and the contemporaneous Cro-Magnons? The mtDNA evidence provides no hint of this so far, and even the species question cannot resolve it, since closely related mammal species may still be interfertile, although the hybrid offspring may not reproduce well, or at all. And the fundamental question is surely whether, when these groups encountered each other, they would have primarily seen each other as essentially ‘same’ or ‘other’ – potential friend, enemy, prey even? In my view, after an evolutionary separation much longer than any between living peoples, they would not only have looked very different in their bodies and faces, but probably also in their skin colour, eyes, hair, body hair, gestures, body language and communication. To which could be added whatever clothing or body embellishments were in use as practicalities or social signals amongst the groups of the time. So even if the two species were reproductively compatible, the two populations may hardly ever have wanted to mate if they didn’t like the look of each other. And if offspring did result, they may not have been favoured as mates by the next generations of either parent group. So paradoxically, hybrids could have been produced,

  but their genes may never have impacted the gene pools of the main populations.

  We don’t, of course, know what language capabilities either the Neanderthals or the Cro-Magnons had, and can only guess at this from what they left for posterity. The Cro-Magnons were as complex as modern hunter-gatherers and foragers in what we can reconstruct of their ways of life, and as well as their campsites and technology they have left behind evidence of their art, symbolism and music (for example bone flutes). For the Neanderthals, there are hints of social complexity in things like their burial of the dead and (apparently late in their history) production of jewellery. But evidence that they buried their dead with flowers and made bone flutes now seems dubious. Claims have been made that the shape and capabilities of the Neanderthal vocal tract could be accurately reconstructed from fossil skulls and jaws, but even the most pessimistic simulations still give the Neanderthals a big enough range of sounds for complex language, provided brain quality and sufficient social complexity were in place for it to develop. So we must keep an open mind on this, although personally I doubt that Neanderthal social complexity had driven the evolution of their languages to anything nearly as elaborate as ours by the time they died out.

  So what really happened to the Neanderthals? Some workers think that there was a relatively gradual merging with the incoming Cro-Magnons, meaning that Neanderthals would indeed have contributed something to future generations of Europeans, even modern ones. They see evidence for this in odd features of Cro-Magnon fossils, which they see as remnants of a Neanderthal heritage. In Britain there is one intriguing, but fragmentary, human fossil that falls into the critical period between 30,000 and 40,000 years ago, when these groups could have been in contact or competition. This is a fragment of an adult upper jaw holding some heavily worn teeth from Kent’s Cavern in Devon, found in 1926, long after the time of MacEnery and Pengelly. It was originally described as an early modern fossil and associated with Aurignacian tools, but recent AHOB research suggests that it is instead associated with earlier leaf point artefacts at the site, in which case it is a unique find that could potentiall
y tell us who made these enigmatic tools. Were they Neanderthal, modern, or perhaps even a mixed population? We are now subjecting the fossil to a battery of different techniques, including an attempt at DNA extraction, to see whether we can determine its affinities. In another highly controversial case the burial of a child from Lagar Velho in Portugal, dated about the same time as Paviland and showing similar treatment with red ochre, has been argued to show signs of a mixed Neanderthal-Cro-Magnon ancestry since it supposedly shows the compact build of a Neanderthal rather than the more lithe form typical of the early Cro-Magnons. However, in all other respects the skeleton seems resoundingly modern, and I doubt that it is anything other than an unusually stocky Gravettian child.

  There is a range of alternative scenarios offered by those who instead believe that the Neanderthals went extinct because of the arrival of the Cro-Magnons. There might have been warfare between the groups, Neanderthals might have been pushed into marginal and less productive environments, they might have been outbred if Cro-Magnons had better infant survival or food procurement strategies, or the moderns might have brought new infectious diseases to which the Neanderthals had no resistance. The truth is, of course, that we don’t even know how often these populations actually encountered each other, but we can guess that population density was low – some estimates put the total population of even the Cro-Magnons at only a few tens of thousands right across Europe. And of course it is possible that given the range across which the Neanderthals lived, from Portugal to Uzbekistan, there was no single cause of their demise. Perhaps the reasons for their extinction in Israel were different from those in the Caucasus, and Italy, and Gibraltar, and Britain.

  A new possibility has emerged with our increased knowledge of the complex climatic changes of the last 100,000 years. It had previously seemed unlikely that climate was important in Neanderthal extinction, because the peak severity of the last glaciation seemed to come about 10,000 years after the Neanderthals had disappeared, and they had obviously survived the cold before, and perhaps were even adapted to it, physically and behaviourally. Yet we now know from more detailed records in the Greenland ice cap and European lakebeds that the European climate between 45,000 and 12,000 years ago was highly unstable. One of the primary reasons for this instability was the fluctuating state of the Atlantic Ocean, which has (and had) a huge influence on European conditions. For example, the latitude of Britain (that is, its position in relation to the Equator and the North Pole) is about the same as Labrador in Canada. Whereas in Britain today summer temperatures average about 15°C, and winter about 6°C, Labrador may only manage about 9°C and –12°C respectively. The sea off Labrador is infested with pack ice and icebergs for eight months of the year, and snow may remain on the ground for up to eight months.