Unlike modern chewing gums, some of the early chewing gums were made of birch tar and other natural substances which have been preserved for thousands of years. Archaeologists found a 5,700-year-old gum that belonged to Stone Age in Denmark and used it to reconstruct the entire genome of an ancient human being.

The sticky, ancient tar-like substance revealed details about a woman, whose identity is believed to have existed some thousands of years ago. Since it is the biggest Stone Age site in Denmark, it adds to wide credibility of the evidence.

Evidence from ancient chewing gum

As per the scientists, ancient people sometimes used to chew birch pitch to warm the pitch up, making it soft and malleable for glue use and also as a medicine, or even for recreational purposes. The researchers claim that such ancient substance chewed by humans long ago left behind saliva evidence of a person, thus enabling the modern scientists to reconstruct the genetic information.

The sample recovered from the Syltholm archaeological site in Denmark, allowed them to reconstruct the ancient genome of the person who chewed the gum thousands of years ago. Lead researcher of the study and evolutionary genomicist Hannes Schroeder from the University of Copenhagen said, "It is amazing to have gotten a complete ancient human genome from anything other than bone.''

DNA sequencing

After the scientists sequenced the DNA samples, they found the ancient human DNA reflecting the oral microbiome of the person who chewed the pitch more than 5,000 years ago. Along with the human DNA, scientists also discovered plant and animal DNA alongside.

In their research paper, researchers wrote:"The DNA is so exceptionally well preserved that we were able to recover a complete ancient human genome from the sample... which is particularly significant since, so far, no human remains have been recovered from the site."

They also mentioned that the outcome of the study highlights the potential of chewed birch pitch as a source of ancient human and non-human DNA. This result can be used to shed light on the population history, health status and even subsistence strategies of ancient populations.

The girl who lived 5700 years ago

The finding from DNA study revealed that the person who chews it was a female, most likely with dark skin, dark brown hair and blue eyes. As per the lead author, such characteristics were visible in other European hunter-gatherers. It suggested that this phenotype was widespread in Mesolithic Europe and that the adaptive spread of light skin pigmentation in European populations only occurred later in prehistory.

Interesting findings

The research revealed that the female, who was named as Lola, was lactose-intolerant, which suggested that the adults evolved the tolerance after dairy farming spread during the Neolithic revolution.

The archaeological finding suggested that the inhabitants of the site heavily exploited wild resources during the Neolithic era, which is the period when farming and domesticated animals were first introduced into southern Scandinavia. Also, the scientists found signs of several kinds of oral bacteria, including microbes associated with gum disease and Epstein-Barr virus, among others.

Mesolithic archaeology researcher Theis Jensen, who was part of the team, said that the Syltholm finding is unique since almost everything was sealed in mud, and that "the preservation of organic remains is phenomenal."