Humans have a long-standing tradition of chewing gum, which may not sound impressive, but is proving invaluable to modern archaeologists.
Ancient DNA has been pulled from gum dated to 10,000 years ago, allowing researchers access to the first ever humans to settle in the Scandinavian region.
Scientists Discover DNA In Gum
Chewing gum in the ancient past is made from birch bark pitch — a far cry from what's available in present time. It was often used as glue by ancient people, but it was also typically chewed on like gum, providing scientists now with DNA that can shed light on the early populations of Scandinavia.
Thus, these ancient lumps are becoming a valuable tool in archaeogenetic studies as an alternative source of human DNA.
In a new study conducted by a team from Stockholm University, researchers analyzed masticated lumps from Huseby-Klev, which is a hunter-fisher site during the early Mesolithic period located on the west coast of Sweden.
Few bones from this period have been located in these area, much less bones that have DNA well-preserved enough to study. The newly recovered DNA from gum is the oldest human DNA to be sequenced from Scandinavia.
It was actually excavated in the early 1990's, but technology at the time wasn't sufficient for the analysis of ancient human DNA.
"It took some work before the results overwhelmed us, as we understood that we stumbled into this almost 'forensic research,' sequencing DNA from these mastic lumps, which were spat out at the site some 10,000 years ago!" said study author Natalija Kashuba who was affiliated with The Museum of Cultural History in Oslo during the research period. Kashuba is currently a Ph.D. student at Uppsala University.
What The DNA Say About The Scandinavian People
Findings published in the journal Communications Biology revealed that the DNA — belonging to two females and one male — are genetically close to other hunter gatherers in Sweden and early Mesolithic populations from Ice Age Europe. Meanwhile, the tools that were found at the site with the chewing gum consisted of lithic technology that were brought to the region from the East European Plain.
It paints a picture of a culture and genetic influx into Scandinavia from two routes, which has been suggested in previous studies.
"Demography analysis suggests that the genetic composition of Huseby Klev individuals show more similarity to western hunter-gatherer populations than eastern hunter-gatherers" explained Emrah Kirdök of the Stockholm University, who conducted the computational analysis of the DNA.