Unlocking the Past

by Martin Jones

  If we step back from HLA genes and microsatellites to think of how this waterhole was used by living people, it is worth remembering that a sinkhole is not an uncommon feature in the Florida landscape. A mobile population of hunter-gatherers roaming a sparsely settled continent 8,000 years ago could and would have stopped by several of these. Yet this one had a special significance for a particular community. It was not just where they rested, drank, and procured their food. It was also where they offered up their dead–not only more than 8,000 years ago, for their direct descendants were still being offered up to their watery grave 1,100 years later. It is as if we were to walk into our local graveyard to find the surnames of our family and neighbours, but on headstones that had been gathering lichen since the days of Alfred the Great and Charlemagne.

  Of equal interest is the fact that this continuity fails to show up in the mitochondrial data. Hauswirth and his colleagues amplified a 168-base-pair sequence within the control region. Among fourteen individuals sequenced, they found eleven distinct haplotypes, another very high proportion. The most distinctive evidence of relatedness came from autosomes, inherited by both sexes, while the mitochondrial evidence, inherited through the maternal line alone, displayed a now familiar level of diversity. The visitors to the Windover Bog displayed the genetic hallmark of patrilocality.

  Once combined studies of mitochondrial, Y and autosomal lines become more frequent, we will no doubt encounter a number of different patterns. We have seen in an earlier chapter how the contrast between mitochondrial and nuclear evidence from both Europe and the Pacific Islands might imply that, in these particular cases, the female lines were less mobile than the male lines. What is significant is that ancient DNA has the potential to discriminate, a potential that will continue to sharpen, both in relation to the particular kin groups and to those who join them from the outside world.

  strangers in their midst

  The modern world is full of outsiders. Today’s cities are geared up to accommodate the stranger, whose money can be exchanged for food, shelter and some kind of instant social life. In the great majority of prehistoric societies, true strangers would have been different indeed. Their entry into a remote village would have been subject to the sanction of the senior members, and under the curious gaze of everyone. These were communities interwoven by kinship and familiarity. Without money, the transactions they made would have been embedded in an intricate fabric of social relations. Ancient DNA may be able to bring elements of that fabric to light, and to illuminate the occasional stranger within it.

  There is an ancient mound of discarded shells, at a place called Takuta-Nishibun on the Japanese island of Kyushu, that was home to many generations of prehistoric fishermen and foragers. Just over 2,000 years ago, this ancient place of food preparation and shelter was transformed into a place to bury the dead. These were the dead of a community that followed what was then a novel way of life. This new generation farmed rice, and their dwelling area had shifted from the ancient mound to a small adjacent village. From their burials in the ancient shell mound, we can tell something about this small community of rice farmers, and their links with a wider world.

  That world stretched out in two directions. In one direction was the Asian mainland. It was from that direction that rice farming had arrived in the not too distant past. Travellers continued to make the crossing, as we can tell from the imported mirrors and objects of metal and glass that accompany the burials on the shell mound. Stretching out in the opposite direction was the Japanese island string, where a different tradition could be found, the much older tradition of fishing and foraging that stretched back 10,000 years. Many have argued that these two traditions were quite distinct, reflecting two different ‘peoples’ with different ways of life, different ancestries, and even different skull shapes and skeletal forms. On this site they seem to be intermingled, an impression backed up by studies of their DNA.

  In a genetics laboratory at Shizuoka, not far from Tokyo, geneticist Horishi Oota extracted DNA from twenty-five skeletons from the Takuta-Nishibun site, together with two other skeletons he had acquired from a nearby site of similar date. Previous researchers had managed to construct from DNA evidence an evolutionary bush, drawn from the entire Japanese island string and neighbouring parts of east Asia. It provided a framework within which Japanese farming populations might be distinguished and separated from pre-agricultural foraging populations. The twenty-five Takuta-Nishibun individuals failed to comply with such a neat categorization. The scatter of their haplotypes across the entire evolutionary bush reflected, not a neat replacement of foragers by farmers, but instead a tangle of intertwined histories, reflected by the close association between farming village and shell mound. That is not to say the village dwellers saw no divisions; they clearly did.

  There were two distinct burial traditions on the mound. Most bodies were placed directly into the mound, but about one third of them were laid to rest within large earthenware jars, one of the commoner practices among early rice farmers in these parts. Oota examined nine individuals buried within jars, and seventeen who had been interred directly within the shell mound. From them, he amplified DNA from the third hypervariable segment of the mitochondrial control region. The bodies interred directly within the mound turned out to be genetically diverse. The seventeen individuals grouped into ten mitochondrial haplotypes. Their internal variation was such that Oota could argue for a distant common ancestry. They were not the descendants of a single lineage of recent arrivals. When he turned his attention to the jar burials, the pattern he found was quite distinct. All nine sequences were within two base-pairs of each other, and six of the nine sequences were identical. Here was a much narrower genetic grouping of individuals, related through the female line and displaying their distinct family identity through the way in which they buried their dead, and no doubt through other rites of passage that evade the archaeological record. This division was not hard and fast. Three of the haplotypes were shared by both burial traditions, and this includes the commonest haplotype among the jar burials, accounting for two-thirds of their number. Against a background of two distinct traditions, there was mixing and intermarriage. That mixing occasionally incorporated individuals from further afield.

  The excavators came across the body of a young girl placed, not on the mound, but rather closer to the rice farmers’ village. When Oota came to examine her mitochondrial sequence, he discovered she was set apart in another way. Her sequence was distinct from that of all the other villagers, and placed her on a rather distant arm of the Japanese family tree. Who was this young girl, and where were her relatives? The Takuta-Nishibun site offered no answer, but there is another archaeological site that does. Just six kilometres to the north of the shell mound, the bodies of a woman and a girl had been laid to rest in earthenware jars, half-way up a hill called Hanaura. Each body was amply adorned with shell bracelets. Perhaps this, and their lofty position on the hill, reflected an equally lofty status in life. The excavators surmised that they might be mother and daughter from a family of shamans. Their DNA indicated that things were a little more complicated.

  The woman and girl were not mother and daughter; their mitochondrial sequences were very different. Furthermore, the woman had precisely the same sequence as six of the nine individuals buried in jars six km to the south. She was essentially part of the same lineage and shared in its burial tradition. The lineage of the girl who was similarly buried and similarly adorned was unusual, but not unknown. Her sequence precisely matched that of the stranger in the south, the young girl buried separately from the other villagers.

  That ancient community on Kyushu Island was already an amalgam of two communities living together. One traced its ancestry back to an ancient time when the sea and its bounty were the basis of life, and the vast mounds of discarded shells upon which they dwelt and buried their dead a symbol of that ancient tradition. The other community traced its ancestry back to a more recent history of migrat
ing rice farmers, coming from a land they still visited for trade. But the latter community intermarried with the first, lived in the same settlement and shared its burial mound. Their physical and genetic differences became blurred and confused. At some stage, two girls arrived from distant parts, perhaps to be betrothed. Both died young, but not before one was fully assimilated, honoured with the prestigious burial accorded to her new family. The other died before any such assimilation. At some distance from the main cemetery, she was buried alone.

  This ancient village in Kyushu demonstrates the two features of prehistoric demography that in so many of the examples explored here are found to co-exist strangely. On the one hand, certain traditions, rooted in the paternal or maternal lineage, can persist for countless generations, creating genetic and cultural patterns that stay more or less intact for hundreds or even thousands of years. Nevertheless there are, within this framework of considerable persistence, countless opportunities for moving beyond the immediate circle of friends and relations, leading to some significant elements of mixing on a far larger geographical scale. Sometimes the exchange of artefacts over long distances allows us to chart the possible routes along which this mixing might have taken place. At other times, as at the Takuta-Nishibun site, biomolecular evidence can actually introduce us to those newcomers who have travelled from afar. However, DNA is not the only bio-molecule that can track these individual travellers.

  isotopic traces of the traveller

  The Chinchorro mummies of the South American coastline provide a rich source of ancient biomolecules beyond DNA alone. The extreme desiccation of the coastal strip has conserved many of the bodies’ proteins, such as the collagen of their bones and the keratin of their hair. The isotopic signals in these confirm just how dependent on the sea the Chinchorro societies were. From their coastal villages they looked back to the rocky slopes rising up to the distant Andes, and saw one of the world’s most parched and barren land surfaces. Facing in the other direction they saw before them a fertile and productive ecosystem, the shallow coastal waters beneath the pleasant warmth of a Pacific sun. No wonder their middens were stacked up with the bones and shells of fish, molluscs, sea-lions and coastal birds, with barely a trace of terrestrial foods. Consequently, the isotopic signal in their proteins is substantially marine, a feature that shows up markedly in the isotopic ratios of carbon, nitrogen and sulphur. Steve Macko established this much from hairs taken from the mummified bodies from the early prehistoric coastal site of Morro, one of the sites discovered when Max Uhle first brought the Chinchorro mummies to light. The isotope ratios for carbon, nitrogen and sulphur all clustered tightly in the range expected from a marine diet.

  By way of contrast, Macko went inland, following one of the fertile green valleys that dissect the barren hills on either side, to the remains of an ancient inland settlement. The margins of these valleys still allow the mummification of corpses and so he was able to collect hair from these also. Here, the isotopes generated a contrasting picture, indicating a diet dominated by terrestrial rather than marine foodstuffs. Although not far apart, the two settlements were separated into distinct food chains, one exploiting the coastal waters and the other the valleys. Their hair retained an isotopic imprint of this lifestyle, and that is how Macko managed to track down movements between them.

  The hair of just one of the inland individuals carried an unmistakably marine signal for each of the isotopes. He died inland, but coursing through his bloodstream was the mark of his coastal diet. He had clearly arrived recently from the coast. As we have seen, the hair responds quickly to a changing diet. Yet he was not sent back home to be buried, but carefully laid to rest at his destination–a direct record of contact and movement between two discrete communities.

  making contact

  All this is still a far cry from placing a name and identity upon a set of bones, as in the case of Joseph Mengele, the ‘Angel of Death’ of Auschwitz. Nevertheless, it is not so far from the recognition of the Romanov family, the study upon which a number of attempts at prehistoric kinship analysis were modelled. It is already clear that the archaeological record will not generate a faithful and unwavering mirror to reflect some later scholar’s cross-cultural patterns, though trends may be there. Such trends as exist, reflecting the changing norms of ancient communities, will be overlaid with evidence for subversion of and deviation from those rules. In addition there will be interlopers to the burial group, travellers from afar. The study of ancient kin is in its infancy, and will no doubt throw up many surprises, especially when mitochondrial and Y haplotypes are examined together. It will also begin to describe the complex interweaving of social networks on larger and larger scales, which may well prove to be the principal story of human prehistory. For a long time those growing networks were hinted at by the sourcing of precious artefacts that had travelled vast distances from their place of origin. Now, with ancient DNA, we can come into contact with families, communities, and the actual individuals who travelled between them.

  afterword

  The potential of biomolecular archaeology to sharpen the focus to particular families, and even to named individuals within them had chimed a loud chord with our perennial fascination with royalty and the nobility. Twenty years ago seminal work on the remains at Ekaterinberg of the Romanov family set a precedent subsequently which has subsequently been followed by a growing list of celebrity names. High up on that list are: Tutankhamun, King Louis XVI of France, and an eighteenth century thoroughbred horse called Eclipse. A recent and popular addition is the English monarch unsympathetically portrayed by William Shakespeare, King Richard III.

  I would have had a much better story to tell if contemporary accounts of the king had been right; that rather than Shakespeare’s ‘hunch-back’ he had been upright, tall, and of fine physique. I would have been able to discuss the bard’s desire to please the Tudor dynasty by demonizing the king they had left dead on the battlefield. I could have suggested that the bard had employed a disabled body as a metaphor evil, in a manner which had now been exposed by science. As it turns out, Shakespeare was, on this occasion, employing no more poetic license than a dutiful hospital orderly. The buried skeleton, unearthed from beneath a Leicestershire car park, now identified by DNA matching as belonging to Medieval England’s last king, did indeed suffer from severe scoliosis of the thoracic spine.

  The study of the king’s body presents another fine example of integrated bio-archaeological research. His sex and age could be inferred from the skeleton itself. His DNA gave some indication of lineage, but also of the colour of his hair and eyes. The stable isotopes in his bones allowed a life journey to be mapped in geographical and dietary terms, from the relatively modest meals of his Northamptonshire childhood, through to the classier wining and dining in has adult life in the Welsh Marches and beyond (a diet much enjoyed by the roundworms found where his gut would have been). CT scans of the skeleton precisely revealed the injuries causing his battlefield death at thirty-two years of age. While we hunger for further knowledge of these celebrity individuals and their private lives, there is another avenue of research into families and individuals illuminating in a different way. When The Molecule Hunt was first written, early research by Stoneking and Stone into the Oneota Culture of Illinois, and by Hiroshi Oota into the Takuta-Nishibun community of Kyushu had already started to explore that avenue. They were showing the possibilities of fine-grained study to examine the family structure of more ordinary people, without names we remember. They might even allow us to reflect on the history of kinship patterns and the origins of the ‘family’ itself.

  Excavations in 2005 in alongside the River Saale had revealed the skeletons of a number of these ordinary people without remembered names. Some were clustered into small groups and placed beneath earthen mounds. They didn’t have a great deal buried with them, but the grave goods did include pots decorated by impressing cordage before they dried. Their ceramic form connected them culturally with other comm
unities, encountered across a wide sweep of northern Europe from the Moskva River in Western Russia to the lakes of Switzerland. Farming communities used such pots throughout the third millennium BC. The skeletons from the Eulau site alongside the Saale were on the western end of that range and the final part of the millennium. Good preservation conditions enabled a detailed biomolecular study of the skeletons.

  One of the small groups studied was composed of four individuals. They had suffered a violent death, but nonetheless had been buried together with care and respect. Skeletal analysis indicated a man of forty to sixty years of age, a woman of thirty-five to fifty years of age, and two infants, both below the age of ten. Using strontium isotope analysis, a method that matches teeth profiles to the geological environs of childhood, the man and two infants clustered to the same isotopic signature, one that fitted well with the location of the Eulau site from which they were excavated. To account for the distinct signature of the woman, we would need to infer a location for her childhood at least 60 kilometres away from Eulau. She was nonetheless related to the infants, as was the man. Her mitochondrial DNA matched the infants’, as did his Y-chromosomal DNA.