Last updated March 28, 2018 at 1:31 pm
Advances in technology continue to improve our knowledge of the interaction between early humans and Neanderthals.
Inside of the Vindija cave, Croatia, where Neanderthal remains were discovered. Credit: M. Hajdinjak
New research suggests that all late Neanderthals separated from a common ancestor from Siberia about 150,000 years ago and that their relatedness is correlated with geographic proximity.
Analysis of the findings shows 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 before these late Neanderthals split at least 70,000 years ago.
An international team sequenced the genomes of five late Neanderthals from fragments of bones and teeth recovered from Belgium, France, Croatia and the Russian Caucasus then compared these to the genomes of other Neanderthals.
Upper Molar of a late female Neandertal discovered during the excavation at Les Cottés cave, France. Credit: M. Soressi/S. Schatz
They 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.
The work also demonstrates that the generation of genome sequences from a large number of archaic human individuals is now technically feasible, and opens up the possibility to study Neanderthal populations across their temporal and geographical range.
In their report, the authors note that the ability to retrieve DNA from a larger number of Neanderthal individuals has been limited by poor preservation and contamination of Neanderthal skeletal remains by large amounts of microbial and present-day human DNA.
“Here we use hypochlorite treatment of as little as 9 mg of bone or tooth powder to generate between 1- and 2.7-fold genomic coverage of five Neanderthals who lived around 39,000 to 47,000 years ago (that is, late Neanderthals), thereby doubling the number of Neanderthals for which genome sequences are available,” they say.
The paper is published in Nature.
