The Seven Daughters of Eve (27 page)

There is a fierce controversy about when America was first colonized. Did the first people arrive across the earlier land bridge or the later one? There are two early archaeological sites in South America which have been used in the past to support the earlier date. One is at an open shelter at Pedro Furada in Brazil known for its rock painting. Flakes of paint have been found in the earth below the rocks at levels which have been dated to seventeen thousand years ago. But there is controversy about whether the flakes fell off the wall at that time or much more recently, working their way down into the lower levels through the action of worms or other creatures that disturbed the soil. The second site is at Monteverde in northern Chile, where fragments of wood, possibly part of a shelter, have been found at levels originally dated at thirty thousand years ago, although this has now been revised to a later date by the archaeologist who excavated the site. No human remains have been found at either Pedro Furada or Monteverde, and a big question hangs over the authenticity of both sites.

Perhaps the greatest evidence against the earlier date for the colonization of the Americas is that one would expect the population, in a land full of game and without prior human occupation, to explode, leaving abundant evidence all over the place. It is not as if nobody has looked. American archaeologists have worked hard to find it; but without success. However, there is plenty of evidence of a continuous settlement after twelve thousand years ago, with hundreds of sites scattered all across both North and South America.

The genetic evidence from modern native Americans also favours the later crossing. The accumulation of mutations in native Americans within each of the four clans has given all of them ages that fall well within the last thirteen thousand years. Reconstructions from modern Siberian and Mongolian patterns show very clearly that the clans were already established and separate from each other well before they reached America. The same applies to the rare fifth clan, that of Xenia, to which about 1 per cent of native Americans belong. As we have already seen, that clan had its origins on the borders of Europe and Asia.

The genetics fits well with the later land crossing from Siberia into western Alaska, just as the Ice Age was waning and the sea levels had begun to rise once again. But getting into Alaska was not the end of the story. Northern America was covered by two huge ice sheets. One enveloped the Rockies and the high mountains of southern Alaska; the other covered the whole of Canada. At the height of the last Ice Age, when sea levels were low enough to expose the land bridge from Siberia, these two great ice sheets fused to seal off access to the interior. The first Americans were faced with a dilemma. If it was cold enough to cross into Alaska by land, it was also too cold to get past the ice sheets on the other side. Alternatively, if it was warm enough to get through the ice sheets, by then the land bridge would be flooded. There had to be a period when the first Americans were stranded in western Alaska. Eventually the two ice sheets withdrew sufficiently to create a narrow corridor between them. This was no verdant valley, but a harsh passage though which the pioneers advanced little by little. At last the corridor opened out into the rich expanses of the Great Plains which were teeming with game. It must have been a wonderful and welcome sight to those first pioneers who had struggled through the ice corridor. From there on, the way was open for the rapid colonization of the whole of North and South America and, judging by the dates of the abundant archaeological sites, this was accomplished at record speed within only a thousand years.

The genetics agrees well with this scenario – except in one detail, namely that one of the four clans, the clan of Ina, is virtually absent from the modern inhabitants of Siberia and Alaska. It is found in South and Central America, and is still abundant in native Americans as far north as Vancouver Island on the north-west Pacific coast, but no further. Intriguingly, this same clan is also the one that is closely associated with the colonization of the Polynesian islands from south-east Asia. As we saw in an earlier chapter, the detailed sequences of Polynesian and native American members of this widespread clan are sufficiently different to rule out a maritime colonization of the Americas from Asia directly across the Pacific via Polynesia. However, the curious absence of this clan from the present-day inhabitants of Siberia and Alaska suggests to me that we may be seeing the genetic echo of a second seaborne colonization that took the coastal route north up the coast of Asia and down the Pacific coast of North America. The rapid sea-level rises which flooded so much of south-east Asia would have given a great incentive to find new land. Could it be that the same maritime migration that ultimately led to the colonization of the remote Pacific islands also led a different branch of this remarkable clan to seek new land to the north – a journey which led them through polar waters and eventually to the temperate lands of Central America? What a voyage that would have been.

People from the Asian mainland also crossed to Japan at about the same time that they first reached America. One of the major questions in Japanese prehistory is the degree to which the modern population can trace its genetic roots to these earlier Jomon settlers, who are believed to have reached Japan about twelve thousand years ago, or to the much later Yayoi and subsequent migrations from Korea in the last two and a half thousand years. This issue has familiar parallels to the question of the composition of the gene pool of modern Europe and whether most Europeans trace their ancestry to the original hunter–gatherers or to the more recently arrived farmers from the Near East. We were able to settle this dispute using mitochondrial DNA. Could the same be done in Japan?

Comparatively little work has been done in Japan but there are hopeful signs that genetics will be able to decide this question. In addition to the Japanese on the central islands of Honshu, Shikoku and Kyushu, anthropologists recognize two other contemporary ethnic groups: the Ainu of Hokkaido in the north, and the Ryukyuans who live mainly on the southernmost island of Okinawa. One theory is that the Ainu and Ryukyuans are the descendants of the original Jomon settlers who occupied the whole of Japan and were then displaced from the central islands to Hokkaido in the north and Okinawa in the south by the arrival of the Yayoi from Korea. What little work has been carried out in Japan agrees in part with this idea, to the extent that it shows modern Japanese from the central islands sharing many more mitochondrial types with modern Koreans than do the Ainu and Ryukyuans. However, it also shows that the Ainu and Ryukyuans do not have very many shared types in common either. Age estimates, similar to the ones we did for the main clusters in Europe, show that both the Ainu and Ryukyuans have accumulated distinct mutations over the past twelve thousand years – which does suggest they are both the descendants of the original Jomon, but also that they have not been in close contact with each other since that time.

Although the majority of modern Japanese now live in Honshu, Shikoku and Kyushu, they do share many mitochondrial DNA sequences with modern-day Koreans and so trace their maternal ancestry back to the Yayoi and subsequent migrations. Many other Japanese are also the maternal descendants of the Jomon and have their closest maternal relatives among the Ainu and the Ryukyuans. Whereas there is no doubt that the genetics confirms that the impact of the Yayoi settlers from mainland Asia was very substantial, far more so than that of the Near Eastern farmers in Europe, still it was not completely overwhelming. Much more needs to be done in Japan; but there is no doubt that mitochondrial DNA shows that modern Japanese are a mixture of Jomon and Yayoi and once again confirms that there is no such thing as a genetically pure classification into different races.

Both America and Japan were first reached by descendants of the hunting bands that had adapted to survive in the harsh conditions of the Asian tundra. This was a very different world from the one their ancestors knew in the Near East. It seemed to take about fifty thousand years spent in the Near East for
Homo sapiens
to acclimatize, both physically and organizationally, to these extreme conditions. But there was another way out of the Near East that did not involve adaptation to life on the tundra and an unrelenting diet of bison and reindeer. That exit was along the coasts of Arabia, the Persian Gulf and Pakistan, south of the great mountain ranges of central Asia, into India and south-east Asia. This route was much warmer, and much more like conditions in Africa, than the freezing northern route. It could have been used straightaway, without the long interlude adapting to the cold of the higher latitudes. Did people travel this southern route by sea thousands of years before their distant relatives eventually moved into Europe and northern Asia? Unfortunately there is no inland archaeology to support the idea of an ancient movement of people along this southern route, and thanks to sea-level rises coastal sites are now under water. But recently hand axes and flakes of the volcanic glass obsidian were found on a raised fossil beach at the edge of the Red Sea. Although no human skeletons were recovered from the site, which means we cannot be sure that the occupants were anatomically related to
Homo sapiens
, this is direct proof of human occupation of coastal sites at a very early date.

Whoever first discovered Australia certainly knew how to travel by boat. Even when sea levels were at their lowest, it was still necessary to make a journey of at least fifty kilometres over open sea to reach Australia. But how long ago did they arrive? Like the early American sites, the dating of very early archaeological finds in Australia has been controversial. However, judging by a recently dated burial site in south-east Australia,
Homo sapiens
was already there at least sixty thousand years ago. Even if these dates are only approximately accurate, they mean that modern humans reached Australia thousands of years before the colonization of Europe and northern Asia had even started.

If the archaeology is inconclusive, what can the genetics tell us? For understandable reasons, native Australians are very wary about participating in genetic tests, particularly those orchestrated by their former oppressors. The outcome is that only very few mitochondrial sequences are known from native Australians. Those that have been published show only the remotest connection with the four clans from northern Asia that settled America. This rules out the possibility that the same hunters that crossed Asia north of the Himalayas and went on to colonize America also turned south and were the first to reach Australia. That much we can be sure of, and it does suggest that there might have been an earlier movement of people from the Near East across southern Asia. Sadly, we currently know so little about the mitochondrial genetics of native Australians that we are not in a position to be more specific about their genetic connections to people from other parts of southern Asia. From the few sequences that have been made public we can see that Australia probably holds several as yet unidentified clans. These are the signs of a very early arrival, leaving plenty of time for mutations to accumulate. They are also the signs of a relatively small population held constant over thousands of years. This fits well with what we know about the arid and hostile conditions that have persisted over this vast continent, which would have kept population growth to a minimum.

I am quite sure that genetics will be able to tell us a lot about how and when the first Australians arrived. I am equally sure that this history belongs to native Australians and not native Europeans like myself. It is their history, not mine. I, for one, would love them to share it with us.

In the last chapter I could see myself slipping into the kind of language about human prehistory that I constantly try to avoid. It is the language of generalization, vitiated by the intentionality implicit in even such innocent-sounding phrases as ‘the first Americans' or ‘the first Australians'. There is an underlying suggestion that these were some sort of cohesive unit with an agreed policy – almost as if they had read the textbooks: ‘OK, chaps, it's fifteen thousand years ago. Time to cross the Bering Land Bridge. And hurry up, it won't last for ever.' Even the Neanderthals: ‘Sorry, lads. Time for us to go extinct and let the Cro-Magnons take over.' This is all complete and utter nonsense. There were no plans. How could there be? No-one can know what lies beyond the horizon. The whole of early human prehistory is based on the decisions of individuals or, at the very most, small bands of not more than a few dozen people.

There is solidity behind the statement: ‘The Romans invaded Britain in
AD
43.' That means something. A well-organized military empire can make decisions and put in place large-scale actions to implement them. But this requires a far greater degree of organization and purpose than can ever have prevailed in our remote past. It is as if our present world of governments, corporations and committees has blinded us to the possibilities and importance of individual small-scale actions. I have tried to emphasize this in the imagined lives of the seven daughters. Though their whole existence depended entirely on uncontrollable elements of their environment – the movement of the herds, the advance and retreat of the ice caps – their day-today responses were a matter of individual choice within those constraints. In this view of human evolution, chance events and contingency are the variables. A boat sinks. A Polynesian island is not discovered for another hundred years.

I like this kind of genetics because it puts the emphasis back where it belongs: on individuals and their actions. This is much more appealing than the old-fashioned type of genetics, which was constrained by its methodology to force people into increasingly meaningless and misleading categories. Until I started this work I always thought of my ancestors, if I thought of them at all, as some sort of vague and amorphous collection of dead people with no solid connection to me or the modern world, and certainly no real relevance to either. It was interesting enough to read about what ‘the Cro-Magnons' got up to all those years ago – but nothing much to do with me. But once I had realized, through the genetics, that one of my ancestors was actually there, taking part, it was no longer merely interesting – it is overwhelming. DNA is the messenger which illuminates that connection, handed down from generation to generation, carried, literally, in the bodies of my ancestors. Each message traces a journey through time and space, a journey made by the long lines that spring from the ancestral mothers. We will never know all the details of these journeys over thousands of years and thousands of miles, but we can at least imagine them.

I am on a stage. Before me, in the dim light, all the people who have ever lived are lined up, rank upon rank, stretching far into the distance. They make no sound that I can hear, but they are talking to each other. I have in my hand the end of the thread which connects me to my ancestral mother way at the back. I pull on the thread and one woman's face in every generation, feeling the tug, looks up at me. Their faces stand out from the crowd and they are illuminated by a strange light. These are my ancestors. I recognize my grandmother in the front row, but in the generations behind her the faces are unfamiliar to me. I look down the line. The women do not all look the same. Some are tall, some are short, some are beautiful, some are plain, some look wealthy, others poor. I want to ask them each in turn about their lives, their hopes and their disappointments, their joys and their sacrifices. I speak, but they cannot hear. Yet I feel a strong connection. These are all my mothers who passed this precious messenger from one to another through a thousand births, a thousand screams, a thousand embraces of a thousand new-born babies. The thread becomes an umbilical cord.

A thousand rows back stands Tara herself, the ancestral mother of my clan. She pulls on the cord. In the great throng a million ancestors sense the tug in lines that radiate out from her source. I feel the pull in my own stomach. On the bright stage of the living, I look to right and left and sense that others feel it too. These are the other people in the clan of Tara. We look at each other and sense our deep umbilical connection. I am looking at my brothers and sisters. Now I am aware who they are, I feel we have something very deep in common. I feel closer to these people than to the others. Like my ancestors, they are all very different to look at; but, unlike my ancestors, I can talk to them about it.

When two people find out that they are in the same clan they often experience this feeling of connection. Very few can put it into words, but it is most definitely there. Though DNA is the instrument which traces the links, I do not believe it has anything directly to do with the sensation. It seems inconceivable that the few genes which are embedded in the mitochondrial genome can directly influence feelings of this kind. They are certainly important genes and, as we saw in an earlier chapter, they allow cells to use oxygen. Without any evidence it would be hard to make a case that it was purely the similarities of cellular metabolism that caused this emotional feeling of shared experience. The DNA is certainly a physical object which has literally been passed from generation to generation, but its power is as a token or a symbol of the shared ancestry it reveals rather than the body chemistry it directly controls.

Many people experience a feeling of closeness and intimacy with others in the same clan. But would they feel this if the DNA tests had not revealed the connection? Two strangers enter a crowded room. Their eyes meet and they feel instinctively drawn to each other but don't know why. Are they acting under the influence of the subconscious awareness of an ancient connection? No research has yet explored this intriguing possibility, but as more and more people find out to which clan they belong, their reactions to their own ancestors and to each other will emerge.

What is it that we share with other members of our clan? We share the very same piece of DNA that has come down from our ancient maternal ancestors. We use it constantly. Cells in every tissue are reading the message it carries and carrying out its instructions millions of times a second. Every atom of oxygen we take into our bodies when we breathe has to be processed according to the formula that has been handed to us by our ancestors. That is a very fundamental connection in itself. But the route by which this gene reached us from those ancestors has its own special importance, for it follows the same path as the bond between a mother and her child. It is a living witness to the cycle of pain, nurture and enduring love which begins again every time a new child is born. It silently follows the mysterious essence of the feminine through a thousand generations. This is the deep magic which connects everyone in the same clan.

It is not a connection which is at all obvious in a world where family history and genealogy are dominated by inheritance through the male line. We are all familiar with the illuminated scrolls which celebrate the pedigrees of the rich and powerful. Without exception these trace the flow of titles, lands and wealth from father to son through the generations. Even the family trees of more modest households are built up around a scaffold of paternal inheritance. The immediate cause of this male monopoly on the past is simply that the written records on which all genealogy depends rely heavily on the use of surnames. With a surname as the only way into the records, it is no surprise that what comes out the other end is a family tree drawn around men. But the ultimate cause is the same patriarchal attitude of Western civilization that we encountered in the first theories of inheritance. Wealth and status were the only things considered to be worth inheriting, and they passed down the male line.

The common practice of women adopting the husband's surname on marriage rather than retaining their maiden names makes it very difficult to trace a maternal lineage, for women's names change at every generation. But neither would retention of the maiden name resolve the problem, because a maiden name is, after all, only another surname – a father's name rather than a husband's. Against this background it is no surprise that it comes as a revelation to many people that there actually is such a thing as a maternal family tree, a mirror image of the traditional paternal version. I have certainly never seen one drawn out.

Genetics does help to reconstruct detailed maternal trees even within the existing records, but the best solution for future generations of genealogists would be to create a new class of name altogether. Everyone would get this name from his or her mother. Women would pass it on to their children. It would be, in effect, an exact mirror image of the present system with its surnames which people get from their fathers and, if they are men, pass on to their children. We would then all have three names: a first name, a surname and a new one, a
matriname
perhaps. A man passes on his surname to his children; a woman gives her matriname to hers. Since they follow a maternal line of inheritance, these names will closely correspond with mitochondrial DNA. They will also reflect biological relationships more accurately than surnames, because there is only very rarely any doubt about the identity of a child's mother. In time people would be able to recognize their maternal relatives with the same matriname in just the same way as they can now link up to their paternal family through a shared surname. But until that time comes, if it ever does, reconstructing maternal family trees through written records alone will be much harder than drawing the male equivalent.

In the short time during which I have been able to help people reconnect to their ancestors or their relatives using DNA, I have received many requests from individuals who have tried to establish a link through the records but for one reason or another have not been able to do so. Paper records can be destroyed by fire, eaten by termites, erased by mould or simply just lost. DNA is able to fill in the gaps created by missing records. This helps to compensate for the inherent frailty of pen and paper; but there are many people for whom the lack of any written records about their ancestors is not an accident but is deliberate obliteration. In these cases, DNA is not just a useful supplement to the traditional techniques of the genealogist. It becomes their only physical link to the past.

For Jendayi Serwah, establishing a link to her past was a mission of great personal significance. She is a lady from Bristol whose parents had each arrived in Britain from Jamaica as teenagers. Their ancestors had been taken from Africa as slaves to work the plantations. But there were no records of this. The only details the slave ships kept were the most basic description of their human cargo: how many men and how many women were loaded on board, and how many survived the long sea voyage, was all that was written down. After they were landed and sold on to the plantation owners, their individuality was deliberately erased. They were given European names. No records were kept of births or marriages or deaths. Their pasts as individuals were intentionally obliterated. It was not that it would have been difficult for Jendayi to trace her ancestors in Jamaica back more than a few generations; it would have been completely impossible. Of course, she guessed that her deep ancestry lay in Africa; but there was no real proof of it, other than the general historical presumption that many captives from west Africa were sold to plantation owners in the Caribbean. So it was not surprising that, when we tested her DNA, Jendayi had a mitochondrial signature that was clearly African. However, when I told her of this result and also that we had found a very close DNA match with a Kenyan Kikuyu, the effect on her was overwhelming. She was literally lost for words. Here at last was the
individual
proof she had wanted for so long. It was as if the DNA was itself a written document from her ancestors, which in a sense it was; a document that had been handed down, one generation at a time, from the woman who had endured and survived that terrible voyage from Africa. A document that could not be obliterated by the plantation owners as it passed unseen and unread through the generations. And now in Jendayi here it was, a perfect copy of the African original preserved within her own body.

I have seen many other astonishing journeys witnessed by this remarkable piece of DNA. In western Europe more than 95 per cent of native Europeans fit easily within one or other of the seven clans. That still leaves a large number of people whose deep maternal lineages tell of a different history. Unlike Jendayi, they are usually completely unaware of the exotic journeys recorded in their DNA. For instance, a primary school teacher from Edinburgh carries the unmistakable signature of the Polynesian mitochondrial DNA which I can recognize from a mile off. She knows her own family history well for the past two hundred years, and there is nothing that gives any clue as to how this exotic piece of DNA came to her from the other side of the world. But there is no doubt that it did. What tales it could tell of the South Seas! Is she perhaps the descendant of a Tahitian princess who fell in love with a handsome ship's captain, or of a slave captured by the Arabs on the coast of Madagascar? There are many other equally mysterious journeys recorded in our DNA: the Korean sequence that turns up regularly in fishermen from Norway and northern Scotland; the unmistakably African DNA in a dairy farmer from Somerset, a legacy perhaps of Roman slaves from nearby Bath; the sequence of a book salesman from Manchester that is so unusual that his closest match is found among the native Australians of Queensland.

One outstanding genetic journey involves a complete circumnavigation of the world. Two fishermen on a small island off the west coast of Scotland have unusual mitochondrial sequences, and I thought at first they might be closely related to one another, although they had no knowledge of it. As we discovered more sequences from different parts of Europe and the rest of the world, we began to find much closer matches to the two men – one in Portugal and one in Finland. These were still unusual sequences to find in Europe, not part of the seven original clans. The Portuguese sequence matched several from South America, and the Finnish DNA was close to sequences found in Siberia, where we also found the ancestral sequence of the South Americans. So the two fishermen were indeed related – but only through a common ancestor from Siberia. One line of maternal ancestors had travelled from Siberia along the coast of the Arctic Ocean to Scandinavia, then on to the west of Scotland, perhaps aboard a Viking ship. The other had crossed into America over the Bering Straits, then down to Brazil. At some time, presumably after Brazil became a Portuguese colony, a woman carrying this piece of DNA crossed the Atlantic to Portugal, from where, somehow, it had found its way up the Atlantic coast to the west coast of Scotland. The two journeys had ended on the same small island after travelling in opposite directions from the other side of the world.