【遺伝学】後期ネアンデルタール人の来歴に関する新知見

The genomes of five Neanderthals who lived 39,000 to 47,000 years ago and are also known as late Neanderthals are described online this week in Nature.

Little is known about the genetic diversity of Neanderthals, or the relationship between late Neanderthal populations at the time of their last interactions with early modern humans and before they eventually disappeared.

Mateja Hajdinjak and colleagues sequenced the genomes of five late Neanderthals from fragments of bones and teeth recovered from Belgium, France, Croatia and the Russian Caucasus. By comparing these to the genomes of other Neanderthals, the authors estimate that all late Neanderthals separated from a common ancestor from Siberia, approximately 150,000 years ago, and that their relatedness is correlated with geographic proximity. Their analysis suggests that the bulk of Neanderthal gene flow into early modern humans originated from one or more populations that diverged from the late Neanderthals that were analysed here before these late Neanderthals split, at least 70,000 years ago.

By comparing the five genomes to that of an older Neanderthal from the Caucasus, the authors also suggest that there was a population turnover towards the end of Neanderthal history, either in the Caucasus or throughout Europe. The timing coincides with pronounced climatic fluctuations between 60,000 and 24,000 years ago, when extreme cold periods in Northern Europe may have triggered the extinction of local populations and subsequent re-colonization from southern Europe or western Asia.