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| Neanderthals in Our Gene Pool? |
Have Neanderthals contributed to our gene pool? This question is related to, but is distinct from, the "out-of-Africa" debate. If Neanderthals had made a substantial contribution to the gene pool of contemporary humans, replacement models like out of Africa would be severely challenged. On the other hand, while the lack of Neanderthal contribution to the contemporary human gene pool would be consistent with the out of Africa model, that particular result alone would not disprove the multiregional hypothesis. It is also possible that there was substantial exchange of genes across many different human populations but that the Neanderthal population was not involved.
How can we tell whether Neanderthals contributed to the contemporary gene pool? You can't get DNA from fossil humans. Or can you? Data from fragments of DNA collected from different Neanderthal fossils have led to the conclusion that Neanderthals probably did not contribute to the contemporary gene pool. In 2000 Igor Ovchinnikov and his colleagues were able to obtain small fragments of mtDNA from a 29,000-year-old Neanderthal fossil found in the Caucasus Mountains. They compared the mitochondrial sequences from their fossil to mtDNA collected from a previously collected Neanderthal fossil from Germany. Ovchinnikov and his collegues concluded "Phylogenetic analysis places the two Neanderthals from the Caucasus and western Germany together in a clade that is distinct from modern humans, suggesting that their mtDNA types have not contributed to the modern human mtDNA pool."4