A short history of nearly everything - Bill Bryson [233]
But all of this overlooked the more or less infinite capacity for surprise offered by the ancient Mungo people of western New South Wales. In early 2001, Thorne and his colleagues at the Australian National University reported that they had recovered DNA from the oldest of the Mungo specimens—now dated at 62,000 years—and that this DNA proved to be “genetically distinct.”
The Mungo Man, according to these findings, was anatomically modern—just like you and me—but carried an extinct genetic lineage. His mitochondrial DNA is no longer found in living humans, as it should be if, like all other modern people, he was descended from people who left Africa in the recent past.
“It turned everything upside down again,” says Thorne with undisguised delight.
Then other even more curious anomalies began to turn up. Rosalind Harding, a population geneticist at the Institute of Biological Anthropology in Oxford, while studying betaglobin genes in modern people, found two variants that are common among Asians and the indigenous people of Australia, but hardly exist in Africa. The variant genes, she is certain, arose more than 200,000 years ago not in Africa, but in east Asia—long before modern Homo sapiens reached the region. The only way to account for them is to say that ancestors of people now living in Asia included archaic hominids—Java Man and the like. Interestingly, this same variant gene—the Java Man gene, so to speak—turns up in modern populations in Oxfordshire.
Confused, I went to see Harding at the institute, which inhabits an old brick villa on Banbury Road in Oxford, in more or less the neighborhood where Bill Clinton spent his student days. Harding is a small and chirpy Australian, from Brisbane originally, with the rare knack for being amused and earnest at the same time.
“Don't know,” she said at once, grinning, when I asked her how people in Oxfordshire harbored sequences of betaglobin that shouldn't be there. “On the whole,” she went on more somberly, “the genetic record supports the out-of-Africa hypothesis. But then you find these anomalous clusters, which most geneticists prefer not to talk about. There's huge amounts of information that would be available to us if only we could understand it, but we don't yet. We've barely begun.” She refused to be drawn out on what the existence of Asian-origin genes in Oxfordshire tells us other than that the situation is clearly complicated. “All we can say at this stage is that it is very untidy and we don't really know why.”
At the time of our meeting, in early 2002, another Oxford scientist named Bryan Sykes had just produced a popular book called The Seven Daughters of Eve in which, using studies of mitochondrial DNA, he had claimed to be able to trace nearly all living Europeans back to a founding population of just seven women—the daughters of Eve of the title—who lived between 10,000 and 45,000 years ago in the time known to science as the Paleolithic. To each of these women Sykes had given a name—Ursula, Xenia, Jasmine, and so on—and even a detailed personal history. (“Ursula was her mother's second child. The first had been taken by a leopard when he was only two. . . .”)
When I asked Harding about the book, she smiled broadly but carefully, as if not quite certain where to go with her answer. “Well, I suppose you must give him some credit for helping to popularize a difficult subject,” she said and paused thoughtfully. “And there remains the remote possibility that he's right.” She laughed, then went on more intently: “Data from any single gene cannot really tell you anything so definitive. If you follow the mitochondrial DNA