No two persons ever read the same book. --Edmund Wilson

Monday, May 29, 2006

#53: The Seven Daughters of Eve -- Bryan Sykes

Accessible pop science from the man responsible for the discovery, via analysis of mitochondrial DNA, that anyone of European ancestry can trace their maternal lineage to one of just seven women, who lived at various times from 45,000 to 25,000 years ago.

I am absolutely fascinated by this notion, I have to say: if I could justify the expense, I'd send £180 to Oxford Ancestors and find out which of the seven was my ancestress. (Though it's possible that it wouldn't be any of them: all depends on some very recent, but as yet still tangled, family history.) Having read the book, though, I have a better understanding of how the process works, and why -- and what sparked the original research.

Sykes is an authority on the analysis of archaeological DNA, having been involved in testing samples taken from the 'Iceman', a 5000-year-old corpse found on a glacier on the Italo-Austrian border. During the analysis of the Iceman's DNA, he discovered that the same DNA sequences were present as were found in modern Europeans. One of the modern matches was a friend of Sykes', and she subsequently reported feeling 'kinship' for the long-dead Iceman, who'd turned out to be a distant, but direct, relative of hers.

Other assignments gave Sykes more sense of the connections that link many people in the modern world directly to historical figures. (Obviously we all have ancestors who lived hundreds, thousands, tens of thousands of years ago; in Roman times; in the time before farming; in the last Ice Age; et cetera.) Studying DNA extracted from skeletons thought to be those of the murdered Tsar and his family, Sykes discovered that he was related to Peter Romanov, the last Tsar: more precisely, that he and the Tsar shared a female ancestor who'd lived (given the rate of mutation of mitochondrial DNA) at some time in the last ten thousand years.

Using evidence from analysis of mitochondrial DNA, Sykes proved that the Polynesian islands were colonised from south-east Asia, rather than from America as Thor Heyerdahl claimed: "I could not help feeling a tinge of disappointment that I had been unable to vindicate the man who had inspired a generation with his voyage in Kon-Tiki."

He also found that there is no trace of Neanderthal mitochondrial DNA anywhere in modern Europe; thus, no interbreeding, or no viable interbreeding. (He hypothesises that the offspring of Neanderthal and Homo Sapiens might have been infertile, like mules, due to chromosomal mismatch.)

And he showed that the Duke of Bath's butler's family have been in the area for longer than the Duke: the butler shares DNA with a 12,000-year-old skull from Cheddar Gorge, but the Duke does not.

There is a fair amount of space given to scientific infighting, but Sykes manages to sidestep any nastiness, and falls over himself to explain away the competition's 'errors' and 'instrument malfunctions'. As far as one can tell, the opposition has conceded that the whole 'mitochondrial DNA' theory is sound.

Perhaps the weakest part of the book, scientifically, is also the most entertaining: the seven chapters that deal with the seven 'daughters of Eve'. As fiction they're perfectly adequate, and some effort has been made to explain aberrations such as the wide geographical spread of two branches of one woman's DNA -- here, the result of one of her daughters being reared by another tribe -- but in the end it can only be fiction, however well researched. Your 'clan mother' might as well be a character from Jean Auel's 'Earth's Children' series.

Still: absolutely fascinating. So what if it has no relevance to anything? Though Sykes tries hard to give it relevance: 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 reveaaled the connection? Two strangers enter a crowded room. Their eyes meet and they feel instinctively drawn to each other but they don't know why. Are they acting under the influence of the subconscious awareness of an ancient connection?

Almost certainly not: but it doesn't stop me wanting to know!

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