Researchers detect Caspian traces in genomes of Swiss people

Genetic studies of Neolithic and Bronze Age skeletons from Europe have provided evidence for strong population genetic changes at the beginning and the end of the Neolithic period.

In a new study published in Nature Communications, researchers analyzed 96 ancient genomes, providing new insights into the ancestry of modern Europeans.

With Neolithic settlements found everywhere from lakeshore and bog environments to inner alpine valleys and high mountain passes, Switzerland's rich archeological record makes it a prime location for studies of population history in Central Europe. Towards the end of the Neolithic period, the emergence of archaeological finds from Corded Ware Complex cultural groups (CWC) coincides with the arrival of new ancestry components from the Pontic-Caspian steppe, but exactly when these new peoples arrived and how they mixed with indigenous Europeans remains unclear.

To find out, an international team led by researchers sequenced the genomes of 96 individuals from 13 Neolithic and early Bronze Age sites in Switzerland, southern Germany and the Alsace region of France.

As a result, they detected the arrival of this new ancestry as early as 2800 BCE, and suggest that genetic dispersal was a complex process, involving the gradual mixture of parallel, highly genetically structured societies.

The researchers also identified one of the oldest known Europeans that was lactose tolerant, dating to roughly 2100 BCE.they detected an arrival of ancestry related to Late Neolithic pastoralists from the Pontic-Caspian steppe in Switzerland as early as 2860–2460 cal BCE.

"Remarkably, we identified several female individuals without any detectable steppe-related ancestry up to 1000 years after this ancestry arrives in the region, with the most recent woman without such ancestry dating to 2213–2031 cal BCE. This suggests a high level of genetic structure in this region at the beginning of the Bronze Age with potential parallel societies living close to each other," said the scientists.

These results show that CWC was a relatively homogenous population that occupied large parts of Central Europe in the early Bronze Age. Still, they also show that people without steppe-related ancestry existed parallel to the CWC cultural groups for hundreds of years.