For the very first time, an entire ancient human genome has been reconstructed by scientists from an old Stone Age “chewing gum.” The modern-age chewing gums containing polyethene plastic may stick around for tens or even hundreds of years. In Denmark, there are preserved some of the ancient chewing gums made of birch tar and other natural substances, including a 5700-year-old piece of the Stone Age.
The research is published in the journal Nature Communications. As per archaeologists, the longevity of the sticky stuff can help piece together the lives of ancient people who left tooth marks. The ancient birch gum in Scandinavia contained enough DNA to reconstruct the full human genome of its ancient chewer. Researchers could identify the microbes that lived in her mouth, and even the menu of a prehistoric meal.
How Did She Look?
Experts have claimed she likely had dark skin, dark brown hair, and blue eyes. Dr Hannes Schroeder from the University of Copenhagen said, “We determined that she had this striking combination of dark skin, dark hair, and blue eyes.”
“It’s interesting because it’s the same combination of physical traits that apparently was very common in Mesolithic Europe. So all these other ancient [European] genomes that we know about, like La Braña in Spain, they all have this combination of physical traits that of course, today in Europe is not so common. Indigenous Europeans have lighter skin colour now, but that was apparently not the case 5,000 to 10,000 years ago.” he claimed. Here is an artist’s illustration of how did the Scandinavian girl look like.
How was Her Lifestyle?
The study says, the individual was part of a world that was continuously changing as groups migrated across the northern regions of Europe. An osteoarchaeologist at Stockholm University, Jan Stora says, “We may expect this process, especially at this late stage of the Mesolithic, to have been complex with different groups, from south, west or even east, moving at different times and sometimes intermingling while perhaps other times staying isolated.”
A co-author Hannes Schroeder, a molecular anthropologist at the University of Copenhagen, Denmark, supposed the time to be the arrival of the farming with changing lifestyles. However, they could not find any farmer ancestry in her genome. The ancient chewing gum helped to discover many more things. The authors explained that the combination of physical traits of the girl had been noted earlier in other European hunter-gatherers.
What about the source of the DNA?
The DNA was stuck in a black-brown lump of birch pitch formed by heating birch bark. At that time, it was used to fix together stone tools. The marks of tooth clearly say the substance was chewed, perhaps to make it more malleable or to relieve toothache or other ailments. Additionally, the researchers also discovered evidence hazelnut and duck DNA - traces thought to have been a recent meal consumed by the individual before chewing the gum.
The Importance of the Discovery
According to the researchers, the information gives us essential information about our ancestor's lifestyle, livelihood as well as health. The DNA extracted from the chewing gum provides detailed info about how pathogens have evolved over the years. "To be able to recover these types of ancient pathogen genomes from material like this is quite exciting because we can study how they evolved and how they are different to strains that are present nowadays," Dr Schroeder.