A new study revealed the oldest Scandinavian human DNA. How? Through studying ancient chewing gums! Scandinavia has few human bones that are almost 10,000 years old. Unfortunately, not all of these bones have sufficient DNA for archaeogenetic studies. The DNA from the newly examined gums, which are chewed birch bark pitch lumps, is the oldest human DNA sequenced from Scandinavia to date. The DNA obtained from one male and two females creates a link between human genetics and material culture. 

A Proxy for Human Bones and DNA

Ancient chewing gums have become an alternative for human bones and human DNA in archaeogenetic studies. The pieces that were investigated came from an early Mesolithic hunter-fisher location on Sweden’s west coast, Huseby-Klev. Excavation of the site started in the early 1990s, but it was impossible to study ancient human DNA at that time. The chewing gums were made from birch bark tar, which was often used as glue in tool production during the Stone Age. Ancient people usually chewed it like gum, giving scientists today the DNA that can provide a glimpse of what the early Scandinavians were like. 

Few bones from this era have been found in the area. The same thing can be said for bones with well-preserved DNA. The recovered DNA from the chewing gums is the oldest DNA of humans to be sequenced from Scandinavia.

Natalija Kashuba who conducted the experiments together with Stockholm University said that when Mikael Manninen and Per Persson suggested finding hunter-gatherer DNA in the mastic lumps from Huseby Klev, they were hesitant but truly impressed that archaeologists were careful during the excavation and preserved the materials. According to Kashub, it took some work before the outcome overwhelmed them as they realized that they found a nearly forensic research. The work involved sequencing DNA from the chewing gums that were left at the site some 10,000 years ago. 

Results of the study were published in Communications Biology.