Neandertal DNA Spells Separate Origins

The second mitochondrial DNA (mtDNA) analysis from a Neandertal--and the first to be done on clearly dated remains--will be disappointing news for those who like the idea of having Neandertals as ancestors.

The new analysis, by William Goodwin of the University of Glasgow and colleagues in Russia and Sweden, is from fragments of the skeleton of an infant Neandertal recently found in a limestone cave in the northern Caucasus, radiocarbon dated to about 29,000 years. The DNA is thus from one of the easternmost as well as most recent populations of Neandertals.

The scientists report in the 29 March issue of Nature that the 256-base pair sequence is 3.48% different from the 379-base pair sequence from the original type specimen, from western Germany's Neander Valley, whose mtDNA was analyzed in 1997 (Science, 11 July 1997, p. 176). That is similar to differences within modern human populations. Neither Neandertal sequence is closer to Europeans than to any other modern human population, giving another knock to the "multiregional" hypothesis, which postulates that modern humans evolved separately in more than one location, and allows for some mixing with Neandertals.

Fred Smith, a multiregional sympathizer at Northern Illinois University in DeKalb, says the new analysis doesn't alter his thinking. "It may well be that 30,000 years ago [not just Neandertals' but] everybody's mtDNA was that much different" from that of modern humans, he says.

Goodwin says the preservation of enough DNA to allow for sequencing in the Caucasus sample raises the likelihood that more will be found to yield secrets of Neandertal population genetics.

Posted in Paleontology, Archaeology