Unveiling secrets of Paleolithic societies through non-destructive DNA isolation

Monday - May 8 2023, 16:02 UTC - 1 year ago

An international research team led by the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, has for the first time successfully isolated ancient human DNA from a Paleolithic artifact: a pierced deer tooth discovered in Denisova Cave in southern Siberia. This break through method could open the door for a greater number of studies in Ancient DNA and may potentially help identify the users of ornaments and tools produced in the deep past.

Researchers from the Max Planck Institute have successfully isolated ancient human DNA from a Paleolithic deer tooth pendant, paving the way for directly identifying the users of artifacts from the deep past and gaining deeper insights into Paleolithic societies.

Artifacts made of stone, bones, or teeth provide important insights into the subsistence strategies of early humans, their behavior, and culture. However, until now it has been difficult to attribute these artifacts to specific individuals, since burials and grave goods were very rare in the Palaeolithic. This has limited the possibilities of drawing conclusions about, for example, division of labor or the social roles of individuals during this period.

In order to directly link cultural objects to specific individuals and thus gain deeper insights into Paleolithic societies, an international, interdisciplinary research team, led by the Max Planck Institute for Evolutionary Anthropology in Leipzig, has developed a novel, non-destructive method for DNA isolation from bones and teeth. Although they are generally rarer than stone tools, the scientists focused specifically on artifacts made from skeletal elements, because these are more porous and are therefore more likely to retain DNA present in skin cells, sweat, and other body fluids.

Before the team could work with real artifacts, they first had to ensure that the precious objects would not be damaged. "The surface structure of Paleolithic bone and tooth artifacts provides important information about their production and use. Therefore, preserving the integrity of the artifacts, including microstructures on their surface, was a top priority" says Marie Soressi, an archaeologist from the University of Leiden who supervised the work together with Matthias Meyer, a Max Planck geneticist.

The team tested the influence of various chemicals on the surface structure of archaeological bone and tooth pieces and developed a non-destructive phosphate-based method for DNA extraction. "One could say we have created a washing machine for ancient artifacts within our clean laboratory," explains Elena Essel, the lead author of the study who developed the method. "By washing the artifacts at temperatures of up to 90°C, we are able to extract DNA from the wash waters, while keeping the artifacts intact." .

The team first applied the method to a sieve scoop from the Paleolithic open-air site Schöningen 13 II-4 in Germany, a site famous for its wooden spears. Indeed, the method successfully revealed that the sieve scoop was handled by at least two individuals of different sexes.

By applying their new technique to the pierced deer tooth pendant from Denisova Cave, the team was able to reconstruct a precise genetic profile of the woman who used or wore the pendant, as well as of the deer from which the tooth was taken. Genetic dates obtained for the DNA from both the woman and the deer show that the pendant was made between 19,000 and 25,000 years ago. The tooth remains fully intact after analysis, providing testimony to a new era in ancient DNA research, in which it may become possible to directly identify the users of ornaments and tools produced in the deep past.