The first humans who settled in Scandinavia more than 10,000 years ago left their DNA behind in ancient chewing gums, which are masticated lumps made from birch bark pitch. This is shown in a new study conducted at Stockholm University and published in Communications Biology.

There are few human bones of this age, close to 10,000 years old, in Scandinavia, and not all of them have preserved enough DNA for archaeogenetic studies. In fact, the DNA from these newly examined chewing gums is the oldest human DNA sequenced from this area so far.

The DNA derived from three individuals, two females and one male, creates an exciting link between material culture and human genetics.

Piece of birch bark chewing gum containing oldest Scandinavian DNA (Image: Natalija Kashuba et al / Nature)