Neanderthal Man Read Online Free PDF

particular, we pointed out that mtDNA offers only a limited view of the genetic history of a species. Because it is transmitted only from mothers to offspring, it reflects exclusively the female side of history. Therefore, if Neanderthals interbred with modern humans, we would detect it only if females crossed over between the two groups. This need not have been the case. In more recent human history, when human groups that differ in social status have met and interacted, they almost always had sex with one another and produced offspring. But this generally occurred in a biased way with respect to what males and females do: in other words, the partner from the socially dominant group was most often male, and the offspring of these unions tended to remain in their mother’s group. Of course, we do not know if such a pattern was typical of modern humans when they came to Europe and met Neanderthals some 35,000 years ago. And we do not even know if modern humans were socially dominant in any sense that would be comparable to what we see among human groups today. But it is clear that looking only at the female side of inheritance tells us only half the story of what happened.
    Another, even more important limitation of mtDNA stems from the way it is inherited. As noted, an individual’s mtDNA does not exchange bits and pieces with another individual’s mtDNA. Furthermore, if a woman has only sons, her mtDNA will become extinct. Because chance plays such a strong role in the history of mtDNA, even if some had passed from Neanderthals to early modern humans in Europe at some point between 35,000 and 30,000 years ago, it may well have disappeared. This limitation does not exist for the chromosomes in the cell nucleus: recall that they exist in pairs in every individual, with one chromosome in the pair coming from the mother and the other coming from the father. When sperm or egg cells are formed in an individual, the chromosomes break and rejoin in an intricate dance that results in pieces being exchanged between them. Therefore, if we are able to study several parts of an individual’s nuclear genome, we would get several different versions of the genetic history of a group. 
    For example, even if, in some parts, the variants perhaps contributed by Neanderthals were lost, this would probably not be the case for all parts. Therefore, by looking at many parts of the nuclear genome, one arrives at a picture of human history that is much less influenced by chance. For this reason, we concluded in our paper that our results “do not rule out the possibility that Neandertals contributed other genes to modern humans.” However, given the evidence at hand, we clearly favored the out-of-Africa hypothesis.
    Our paper was peer-reviewed and accepted for publication by Cell after only minor revisions. As is typical for all top journals, the editors at Cell insisted that we not talk about our results before publication in the July 11 issue. {2} They prepared a press release, and I flew to the press conference they organized in London for the day of the publication. It was my first press conference and the first time I’d ever found myself at the center of such intense media attention. Much to my surprise, I enjoyed trying to get across the essence of our work, doing my best to describe both our conclusions and the caveats involved. It was not that easy, because our data had direct implications for a pitched battle that had been raging in the field of anthropology for over ten years.
    This battle had been initiated by the out-of-Africa hypothesis, which Allan Wilson and his colleagues had proposed based largely on the patterns of present-day human mtDNA variation. Initially, the idea had been met with ridicule and hostility by the paleontological community. Almost all paleontologists at the time subscribed to the so-called multiregional model for the origin of modern humans—holding that modern humans evolved on several continents, more