STOCKHOLM, Sweden: Chewing gum has long been something that many people use. In a recent discovery in Scandinavia, researchers have found that the first humans who settled in the area more than 10,000 years ago left their DNA behind in ancient chewing gum. The gum, made up of masticated lumps of birch bark pitch, has produced the oldest human DNA sequenced from the region.
In Scandinavia, there are very few human remains that are older than 10,000 years and not all of them have preserved enough DNA for archaeogenetic studies. This discovery of three individuals’ DNA, that of two females and one male, creates an interesting link between material culture and human genetics and shows a close genetic affinity to other hunter-gatherers in Sweden and to early Mesolithic populations in Ice Age Europe.
According to the researchers, ancient chewing gum is an alternative source for human DNA and possibly a good proxy for human bones in archaeogenetic studies. The investigated pieces come from Huseby Klev, an early Mesolithic hunter-fisher site on the Swedish west coast. The site was excavated in the early 1990s, but at the time it was not possible to analyse ancient human DNA at all, let alone from non-human tissue.
“When Per Persson and Mikael Manninen proposed to look for hunter-gatherer DNA in these chewing gums from Huseby Klev, we were hesitant but really impressed that archaeologists took care during the excavations and preserved such fragile material,” said Natalija Kashuba, who was affiliated to the Museum of Cultural History at the University of Oslo when she performed the experiments in cooperation with Stockholm University.
Dr Emrah Kirdök of the Archaeological Research Laboratory at Stockholm University, who conducted the computational analyses of the DNA, stated: “Demography analysis suggests that the genetic composition of Huseby Klev individuals show more similarity to western hunter-gatherer populations than eastern hunter-gatherers.”
According to the researchers, the chewing gum may have potential not only for tracing the origin and movement of different groups but also for providing insights into their social relationships, diseases and food.