Stone Age humans chewed birch bark pitch, or birch tar, to make a glue-like paste that could be used for tool construction and other kinds of technology. Photo by Jorre/ Wikimedia Commons /CC

May 15 (UPI) -- Scientists have recovered human DNA from 10,000-year-old chewing gum found in Sweden. The DNA is the oldest to be sequenced from the region.

Researchers found the masticated lumps of birch bark pitch, a sap-like tar, among the remains of an early Mesolithic hunter-fisher site called Huseby Klev, located on Sweden's west coast.


During the Stone Age, humans used the bark-derived chewing gum as a glue to make tools. The pieces of gum were originally found in the 1990s, but scientists had yet to develop the technology necessary to process human DNA.

Scientists in Sweden and Norway were able to successfully extract DNA from the masticated gum and sequence the genome of three human individuals.

DNA analysis showed the individuals were closely related to other groups of hunter-gatherers in Scandinavia, as well as Mesolithic populations in Europe. However, the tools found at Huseby Klev are part of technological lineage that archaeologists have traced to the East European Plain, modern day Russia.

The new genetic data, detailed this week in the journal Communications Biology, suggests Scandinavia hosted a unique convergence of disparate genetic and technological lineages.

"Demography analysis suggests that the genetic composition of Huseby Klev individuals show more similarity to western hunter-gatherer populations than eastern hunter-gatherers," Emrah Kirdök, researcher at Stockholm University, said in a news release.

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Scientists hope new discoveries of ancient DNA will provide further insights into the origins, migration patterns and behaviors of the earliest Scandinavian settlers.

"DNA from these ancient chewing gums have an enormous potential not only for tracing the origin and movement of peoples long time ago, but also for providing insights in their social relations, diseases and food," said Per Persson, researcher at the Museum of Cultural History in Oslo.