Scientists from the Globe Institute, University of Copenhagen, extracted a complete human DNA from a Neolithic “chewing gum” material made from birch pitch that is believed to have been chewed by a female.
Birch pitch is a black-brown substance produced by heating birch bark. Researchers say that it was used in prehistory as glue for many purposes, but was also chewed.
"It is amazing to have gotten a complete ancient human genome from anything other than bone. What is more, we also retrieved DNA from oral microbes and several important human pathogens, which makes this a very valuable source of ancient DNA, especially for time periods where we have no human remains," project leader Hannes Schroeder, an associate professor at the University of Copenhagen’s Globe Institute, said in a statement.
Researchers assumed that the Stone Age woman whose DNA was found on the pitch probably had dark skin, dark hair and blue eyes. They also believe that she was genetically more closely related to hunter-gatherers from mainland Europe than to those living in central Scandinavia at the time.
Alongside the DNA of the Stone Age woman, researchers also extracted the DNA of several oral microbiota and pathogens that are related to the Epstein-Barr Virus, which causes infectious mononucleosis, or glandular fever.
“Our ancestors lived in a different environment and had a different lifestyle and diet, and it is therefore interesting to find out how this is reflected in their microbiome. It can help us understand how pathogens have evolved and spread over time, and what makes them particularly virulent in a given environment. At the same time, it may help predict how a pathogen will behave in the future, and how it might be contained or eradicated,” said Hannes Schroeder.
Following the discovery, an artist based the face of the Stone Age woman on his interpretation of descriptions of the woman's probable appearance, given by the researchers.
The full study of the research, supported with the Villum Foundation and EU research programme Horizon 2020, was published in the journal Nature Communications.