NEW YORK (GenomeWeb News) - By analyzing the mitochondrial DNA from the molar of a Neandertal child, a group of French and Belgian researchers have found that the genetic diversity among Neandertals was higher than previously thought.
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The researchers, led by Catherine Hanni and Ludovic Orlando of the Ecole Normale Superieur in Lyon, France, sequenced a 123-base pair section of mitochondrial DNA from the Neandertal child, who was 10-12 years old, and lived in the Meuse valley in Scladina cave, Belgium. They compared this sequence -- the oldest Neandertal mitochondrial DNA sequence ever recovered -- with considerably younger Neandertal sequences that had already been published.
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The study confirmed that Neandertals and modern humans were only distant relatives: Neandertal mitochondrial DNA did not exhibit drastic modification around the time of cohabitation with modern humans, and Neandertal sequences are all closer to each other than to any known human sequence. This suggests that though Neandertals cohabitated with modern humans, little, if any interbreeding took place between the two species.
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The study also revealed that the genetic diversity of Neandertals had been previously underestimated. The mitochondrial DNA from the Scladina sample is a more divergent relative to modern humans than mitochondrial DNA from recent Neandertals.
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The study will be published tomorrow in Current Biology.