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121 of 135 people found the following review helpful:
4.0 out of 5 stars
Sykes' secret, April 21, 2002
Oxford geneticist Bryan Sykes, author of The Seven Daughters Of Eve: The Science That Reveals Our Genetic Ancestry just might have what it takes to become another Carl Sagan or Louis Leakey - that rare scientist with both the scientific skills and genius for self-promotion needed to make himself a household name. Sykes has many talents, as well as some useful vices. As this book shows, he's a fine popular science writer. He also has a sizable ego and a flair for self-dramatization that annoys other scientists but appeals to the public. He often tends to portray himself in The Seven Daughters as a Galileo single-handedly doing battle with the benighted masses of anthropologists and geneticists like Stanford's distinguished L.L. Cavalli-Sforza, who, according to Sykes' not exactly neutral account, just didn't want to admit the importance of his mitochondrial DNA research. Most importantly, though, Sykes has grasped a simple fact about population genetics that resounds emotionally with the average person, yet has largely eluded most learned commentators. Namely, genes are the stuff of genealogy. Each individual's genes are descended from some people, but not from some other people. Thus, Sykes discovered, people often feel a sense of family pride and loyalty to others, living and dead, with whom they share some DNA. Further, if you read between his lines, you can readily understand why - despite all the propaganda that "race does not exist" - humanity will never get over its obsession with race: Race is Family. A racial group is an extremely extended family that is inbred to some degree. In fact, people are so interested in tracing their family connections that Sykes has gone into business for himself. He started a for-profit firm OxfordAncestors.com. "Discover your ancestral mother," he advertises. For [money] he'll trace your DNA (actually, a particular set of your specialized mitochondrial DNA) back to one of the seven Stone Age women who are the ancestors in the all-female line of 95% of all white Europeans. Sykes calls these "the Seven Daughters of Eve." (He's piggybacking on the much-publicized concept of the primordial "Mitochondrial Eve" from whom all women are supposedly descended.) One of his sales slogans: "Which daughter was your ancestor?" (If you happen to be from a non-European race, well, Sykes has got 27 other matrilineal clans sketchily worked out for you. Still, the Eurocentric, cashocentric Sykes tends to treat those non-Caucasian ancient mothers as if they were The Twenty-Seven Stepdaughters of Eve.) Some scientists are appalled by Sykes' shameless entrepreneurialism. Myself, I think that the self-effacing saints like the late William D. Hamilton (the greatest theoretical biologist of the 20th Century and the genius behind more famous biologists like Edward O. Wilson and Richard Dawkins) and the attention-seekers like Sykes both serve useful purposes in advancing science. The key to Sykes' business is that within a particular set of stable "junk DNA" in the mitochondrial code, mutations happen every 10,000 years on average. Last spring, in "Darwinophobia I," I explained why junk genes are so useful to geneticists studying individual or racial genealogies, yet so useless to the bodies they inhabit since they don't do anything. But these genes' uselessness means they aren't subject to Darwinian selection. So they are passed on unchanged, except by random mutations. Of course, precisely because population geneticists like Sykes and Cavalli-Sforza study only useless genes that don't do anything, they don't have anything credible to say about useful genes, like the ones that influence IQ. To learn about nonjunk genes, you need to read behavior geneticists like twin expert Nancy Segal or intelligence gene finder Robert Plomin. Without going into the technical details, a study of mitochondrial DNA allows you to track the line of purely female descent in your genealogy. This is the opposite of the "paternal line of descent" by which your surname came down to you. (The male line can be tracked through tests of the Y chromosome.) The maternal line is your mother's mother's mother's etc. - all female, all the way back. You can visualize your maternal line this way. Mentally lay out your family tree, with you at the bottom. Place your father above you to the left and your mother above you to the right. Fill in all your grandparents, great-grandparents, and so forth, always keeping the males to the left in each pair. Then, the matrilineal line of descent is the extreme right edge of your family tree (just as your last name comes from the extreme left edge). Sykes has put together a chart of these functionally trivial but genealogically interesting mutations that allow him to state, for example, that the woman who claimed to be Anastasia Romanov (who was portrayed by Ingrid Bergman in her Oscar-winning performance in Anastasia) could not have been the daughter of the Czarina murdered by Lenin. (Of course, considering how many surviving members of the Romanov extended family she fooled into thinking she was Anastasia, the possibility remains that she might still have been some kind of biological relative of the Romanovs. Perhaps she was fathered illegitimately by a member of the Czar's side of the family. Neither Sykes' matrilineal test, nor a Y chromosome patrilineal test can rule that out.) Sykes has identified seven mitochondrial mutations of particular genealogical importance. Logically, for each mutation there existed an individual woman. Who were these seven women? They weren't the only women alive at the time. They probably weren't even the first ones to be born with their distinctive mutant junk gene. Each of the seven daughters is simply the first after the appearance of their mutation to have a daughter who had a daughter who had a daughter and on and on in an unbroken line of female descent down to the present day. They are special only in the rather arbitrary genealogical sense of each being on the extreme right edge of the family tree of tens of millions of modern Europeans.
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