6,000-year-old 'chewing gum' holds DNA secrets from Neolithic Europe

Researchers from the University of Copenhagen analyzed 6,000-year-old chewed birch tar artifacts, used by Neolithic communities in the European Alps, to uncover insights into daily life and gender roles during that era. Birch tar, known as the oldest synthetic material, was used for medicinal purposes due to its antimicrobial properties, as well as for making stone tools, repairing pottery, and chewing. The tar’s ability to preserve DNA allowed the team to extract human, microbial, plant, and animal DNA from 19 samples, revealing information about diet, health, and social practices. The study found male DNA associated with tar used on stone tools and female DNA linked to tar used on pottery, suggesting a division of labor where men handled stone tools and women worked with pottery. Some tar pieces contained DNA from linseed and poppy seeds, though the purpose of poppy use remains unclear. The presence of oral microbial DNA confirmed that some tar pieces were chewed, possibly to soften the tar for practical use.