jerry submitted, created time 5 months 2 weeks (sciencenow.sciencemag.org)

When it comes to the extremely difficult task of sequencing caveman DNA, the third time may be the charm for David Caramelli. After two controversial attempts, the biological anthropologist at the University of Florence, Italy, and colleagues claim to have successfully sequenced mitochondrial DNA (mtDNA) from the fossils of a Cro-Magnon, a 28,000-year-old European ancestor of living humans. The mtDNA matches that of some modern Europeans but differs from that of Neandertals, shedding light on the fate of these ancient hominids.

The purpose of this difficult exercise was to attempt to discover whether cro-magnon humans drove neandertals to extinction, the Out-of-Africa hypothesis, or whether they interbred with neandertals, absorbing them into the population, the multiregional hypothesis. Comparisons of neandertal DNA with modern human DNA show few similarities, suggesting that the Out-of-Africa hypothesis is correct, but critics have pointed out that the neandertal genes might have faded from the genome over the intervening millennia. Comparing neandertal DNA to that of cro-magnon specimens from only a few thousand years later could solve this problem and give a more reliable answer.

The results are shown in the journal PLoS One: The two cro-magnon specimens do not show signs of neandertal DNA.

Although it is possible that the DNA results came from a trace of skin that one of the bones' modern handlers left on the sample, great precautions were taken to avoid this. As Science magazine puts it, "This time, only seven people handled the fossils, and the researchers verified that their DNA did not match that of the purported Cro-Magnon sequence."

Keywords: neandertals mitochondrial DNA neanderthals cro-magnon Out-of-Africa hominids human evolutionary biology multiregional hypothesis Out of Africa Hypothesis DNA cavemen