Bryan Sykes - The Seven Daughters of Eve: The Science That Reveals Our Genetic Ancestry

Where do I come from?

How often have you asked yourself that question? We may know our parents, even our grandparents; not far beyond that, for most of us the trail begins to disappear into the mist. But each of us carries a message from our ancestors in every cell of our body. It is in our DNA, the genetic material that is handed down from generation to generation. Within the DNA is written not only our histories as individuals but the whole history of the human race. With the aid of recent advances in genetic technology, this history is now being revealed. We are at last able to begin to decipher the messages from the past. Our DNA does not fade like an ancient parchment; it does not rust in the ground like the sword of a warrior long dead. It is not eroded by wind or rain, nor reduced to ruin by fire and earthquake. It is the traveller from an antique land who lives within us all.

This book is about the history of the world as revealed by genetics. It shows how the history of our species, Homo sapiens , is recorded in the genes that trace our ancestry back into the deep past, way beyond the reach of written records or stone inscriptions. These genes tell a story which begins over a hundred thousand years ago and whose latest chapters are hidden within the cells of every one of us.

It is also my own story. As a practising scientist, I am very lucky to have been around at the right time and able to take an active part in this wonderful journey into the past that modern genetics now permits. I have found DNA in skeletons thousands of years old and seen exactly the same genes in my own friends. And I have discovered that, to my astonishment, we are all connected through our mothers to only a handful of women living tens of thousands of years ago.

In the pages that follow, I will take you through the excitement and the frustrations of the front-line research that lies behind these discoveries. Here you will see what really happens in a genetics laboratory. Like any walk of life, science has its ups and downs, its heroes and its villains.

On Thursday 19 September 1991 Erika and Helmut Simon, two experienced climbers from Nuremberg in Germany, were nearing the end of their walking holiday in the Italian Alps. The previous night they had made an unscheduled stop in a mountain hut, planning to walk down to their car the next morning. But it was such a brilliantly sunny day that they decided instead to spend the morning climbing the 3,516 metre Finailspitze. On their way back down to the hut to pick up their rucksacks they strayed from the marked path into a gully partly filled with melting ice. Sticking out of the ice was the naked body of a man.

Though macabre, such finds are not so unusual in the high Alps, and the Simons assumed that this was the body of a mountaineer who had fallen into a crevasse perhaps ten or twenty years previously. The following day the site was revisited by two other climbers, who were puzzled by the old-fashioned design of the ice-pick that was lying nearby. Judging by the equipment, this alpine accident went back a good many years. The police were contacted and, after checking the records of missing climbers, their first thought was that the body was probably that of Carlo Capsoni, a music professor from Verona who had disappeared in the area in 1941. Only days later did it begin to dawn on everybody that this was not a modern death at all. The tool found beside the body was nothing like a modern ice-pick. It was much more like a prehistoric axe. Also nearby was a container made from the bark of a birch tree. Slowly the realization sank in that this body was not tens or even hundreds but thousands of years old. This was now an archaeological find of international importance.

The withered and desiccated remains of the Iceman, as he soon came to be known, were taken to the Institute of Forensic Medicine in Innsbruck, Austria, where he was stored, frozen, while an international team of scientists was assembled to carry out a minute examination of this unique find. Since my research team in Oxford had been the first in the world to recover traces of DNA from ancient human bones, I was called in to see whether we could find any DNA in the Iceman. It was the irresistible opportunity to become involved in such thrilling discoveries that had persuaded me to veer away from my career as a regular medical geneticist into this completely new field of science, which some of my colleagues regarded as a bizarre and eccentric diversion of no conceivable use or consequence.