Friday, November 17, 2006

Neandertal DNA part II

The issue of Science has arrived with the stories involving the study of the Neandertal DNA. The new test, called "metagenomics," has so far identified 65 250 base pairs of what is believed to be Neandertal DNA. The article is behind a subscription wall, so I cannot quote liberally. Here are the high points:

- Neandertals and modern humans share a common ancestor back c. 706 000 years ago
- The Neandertal/modern human split was c. 370 000 years ago, although it varies for different populations tested.
- This predates the appearance of modern humans in Africa which occurred c. 195 000 years ago.
- There is a lack of evidence supporting admixture of Neandertals and modern humans.

Not everyone thinks the results are fool-proof, however. Genomicist Stephan Schuster of Pennsylvania State University State College is quoted in a companion article by Elizabeth Pennisi as saying:

“The divergence [between living people and Neandertals] is so small compared to the DNA damage and the sequencing error” that it’s hard to be confident of any results. If we’ve learned anything, it is that we generally haven’t perceived the full extent of the problems and complexities of ancient DNA research. We’re still very much in the learning curve."

We haven't heard the last of this one. Stay tuned.

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