A 5,700-year-old piece of chewed-up 'gum' was hiding an entire human genome

How many times have you been grossed out by wads of gum stuck to the sidewalk or the bottom of your chair — or really anything? But did you think about the fact that the complete genetic info for the person who once chewed that gum could be hiding in there?

If you go back 5,700 years, you couldn’t just buy a pack of gum. The alternative in those days was tree sap, like the birch pitch that ancient Danes used to chew on. Now a research team has unearthed the entire genome of a Neolithic girl who spit out such a thing. What is even more amazing is that, without a skull or any bones at all, they were able to use the DNA extracted from that piece of (extremely) stale gum to create an eerily lifelike digital reconstruction of “Lola” that seems to gaze at you across thousands of years.

“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,” said team lead Hannes Schroeder in a study recently published in Nature Communications, while noting that genes frozen in time “can be used to shed light on the population history, health status, and even subsistence strategies of ancient populations.”

There was more than just human DNA in the birch pitch, which was produced by heating birch bark and possibly used as medicine because of its antiseptic properties. It may have even been used as toothpaste, in addition to being an ancient form of chewing gum.

Schroeder’s team was also able to get microbial DNA out of the pitch, piecing together Lola’s oral microbiome. There was also plant and animal DNA that could have clued in the scientists as to what she might have eaten before getting rid of the gum.

Radiocarbon dating found out that Lola was alive during the Neolithic period, the last phase of the Stone Age. Her DNA revealed genotypes for dark skin, dark hair, and blue eyes. Despite having lived in Denmark, she has the genetics of western hunter-gatherers, who had those physical characteristics rather than the Neolithic farmers she might have been assumed to come from otherwise. There is also a legit reason to believe she was chewing that birch pitch for medicinal reasons. Based on bacteria found in the specimen, she possibly had strep.

Think about that next time you spit out your gum.

(via Nature Communications)