"The Seven Daughters of Eve" by Bryan Sykes

"The Seven Daughters of Eve" is full of such juicy tidbits. Sykes has both an ingrained sense of how to make headlines and an unforced ability to explain the technical side of his work in layperson's terms, both of which probably drive his scientific rivals nuts. From their point of view, however, the explosive aspects of Sykes' work developed from his idea that you could use mitochondrial DNA to analyze not merely relationships between individuals but between groups. This was based on his theory (originally controversial, but now pretty well accepted) that mitochondrial DNA mutates at a constant rate. If you and I have the same mitochondrial DNA, our shared maternal ancestor was relatively recent. If our mitochondrial DNA varies by one mutation, she lived about 10,000 years ago; if by two mutations, then she lived 20,000 years ago and so on. (So there were 14 mutations between Tupuaku and Roberts, the largest number Sykes has seen.)

So by tracking differences in mitochondrial DNA between living people, and comparing them to DNA extracted from archaeological specimens, Sykes arrived at both his seven-clans-of-Europe theory and at the mitochondrial Eve. Along the way, he adds, he solved one of the great mysteries of paleoanthropology, establishing genetically that Polynesians migrated eastward from Southeast Asia rather than westward from South America (and that, since they traveled against the prevailing winds, they must be ranked among the greatest mariners the world has ever known).

It's hard to overemphasize the effect Sykes' work has had on the study of early humanity. A large and influential group of physical anthropologists has long argued that the point of human origin in Africa lay millions of years in the past, and that modern Homo sapiens evolved gradually in many different parts of the world. According to this school, modern Europeans might be descended from Neanderthal man, modern Africans from the early species known as Homo erectus and modern Asians from similar ancestor species found in China and Java.

Certainly not all these anthropologists have changed their views, but Sykes -- who insists he came to this subject as an agnostic -- comes down decisively on the side of their opponents, often called the "replacement" school or the "out of Africa" school. These scientists have argued in favor of "a much more recent expansion of Homo sapiens" from its African origin, an expansion in which the Neanderthals and other precursor species were driven away, outcompeted or simply killed off.

Neanderthal DNA, according to Sykes, is nothing like ours; they were undoubtedly our distant cousins -- perhaps twice as distant as the relationship between Teri Tupuaku and Gwyneth Roberts -- but they were a separate human species, now extinct, and not our ancestors at all. It is by no means certain that Neanderthals and modern Homo sapiens (known conventionally in Europe as Cro-Magnon man) could even interbreed, a question Sykes still hopes to solve.

Sykes admits to being a little surprised and disappointed by this conclusion (he doesn't discuss the Cain-and-Abel guilt we should perhaps feel on behalf of our genocidal ancestors), but the idea that humanity is a closer-knit family than we suspected is exciting enough on its own terms. Sykes' book focuses mainly on European ancestry, both for personal reasons and perhaps for marketing ones as well, but in no way does he argue that there is anything special or unusual about the DNA of European or so-called Caucasian people. Indeed, from the genetic point of view, he says, "objectively defined races simply do not exist."

The study of genetics and human evolution has sometimes been perverted to the service of bogus quests for "racial purity." What the science really tells us, in the words of Arthur Mourant, a pioneer in blood-group research, is that "the races of the present day are but temporary integrations in the constant process of ... mixing that marks the history of every living species." Sykes reports identifying unmistakably Polynesian DNA in an Edinburgh schoolteacher, Korean DNA signatures in Norwegian fishermen and African DNA in a white dairy farmer in rural England. Two fishermen on a remote Scottish island turned out to share Siberian ancestry -- but one by way of Finland, the other via Brazil.

I so thoroughly enjoyed "The Seven Daughters of Eve," with its combination of arrogance and humility and its detours into hamster genealogy (yes, really), the place of artistic creation in human evolution and bitchy scientific infighting, that it's painful to discuss one particular device Sykes resorts to: his "Clan of the Cave Bear" efforts to breathe life into his seven European foremothers. He has named all 33 of the clan mothers he has identified worldwide (there are undoubtedly more in Australia and Oceania), to remind himself that they were real people, he says. That is defensible, even charming. But the imaginative life histories we get of Xenia, Katrine, Jasmine, Helena, Velda, Ursula and Tara -- are these prehistoric women or this year's graduating class at Vassar? -- are highly unfortunate.

Sykes never seems fully comfortable with this material, which is simultaneously pedantic and purple ("Two gigantic tusks formed the door"), and one wonders if he felt pressured into it by Oprah-hungry publicists or tabloid journalists who demanded to know which of these hypothetical ancestors provided Jennifer Lopez's derrière. Speed-read through this stuff and it seems harmless enough: Neanderthals are banished, wolves are tamed, boats are created accidentally and seeds dropped on the ground are discovered to produce grain. Sykes' central lesson is so fascinating and indeed so urgent -- we are family, in the most tangible and literal sense -- that he can be forgiven a little hokum.

• View blog reactions