Archaeologists have recently discovered a 5,700-year-old wad of “chewing gum” made from birch tar. The 2cm long lump was found at Syltholm on Lolland Island during the archeological excavation. It was before the construction work of the Fehmarn tunnel to connect Denmark to Germany.
A study has been published in the journal “Nature Communications” which describes the first-ever case of extracting complete human genome and an unprecedented amount of DNA from an ancient piece of gum.
The research conducted reveals that a young girl closely related to western hunter-gatherers from continental Europe discarded chewing gum made birch tar at the dawn of the Neolithic Era. This type of material is comparable in quality to well-preserved teeth and skull bones when looking for DNA from ancient pathogens.
“This is the first time anyone has got a full ancient genome from anything other than bone or teeth. The preservation of the gum is quite extraordinary. We didn’t expect to get the whole genome.” said Hannes Schroeder, a molecular anthropologist, and geneticist at the University of Copenhagen.
The scientists have named the young girl Lola and her genetic analysis describes that she was a dark-haired woman with dark skin tone and blue eyes. The gum also revealed that her last meal was probably duck and hazelnuts. Alongside that, it was also discovered that she couldn’t digest milk.
Further genetic analysis revealed her oral microbiome which consisted of 40 mouth microbes and pathogens that often nest harmlessly inside the mouth. Bacterial species like pneumoniae which causes pneumonia and Porphyromonas gingivalis were detected. Epstein-Barr virus, which can cause glandular fever was also spotted.
“Now we can look at the evolution of specific pathogens, like EBV, and how these bugs change in terms of their virulence,” Schroeder said. “To be able to get these ancient pathogens’ genomes allows you to see how they evolved and spread.”
One might wonder what exactly is birch tar that has successfully contained so much ancient data over the years. It is a natural adhesive that was used in the Middle Pleistocene Era approximately 760,000 to 126,000 years ago.
The material was extracted by heating the tree’s bark and was used to repair arrowheads and other tools. It may have other applications too like it may have served prehistoric toothbrush because of the antiseptic oils which relieved toothaches.
When the material used to solidify, the hunters pitched it in their mouths and chewed it like we currently chew bubble gum.
Theis Jensen, a researcher at the University of Copenhagen said, “It’s incredible because there are periods where we don’t have any bones, but birch pitch survives very well. It’s a substitute for bones, and it’s very intimate. You get so much information.”
This research has been a great success in the world of archaeology as at this point scientists have accumulated thousands of historic human genomes which will help in unveiling more information and will contribute to this scenario. This will reconstruct the past in a way that has never been done before.