If the human race manages to survive a few more millennia, what relics will the people of the year 7920 and their robot overlords have to understand our times? Will the oceans still be full of our garbage? Will our Facebook pages still be active? Of all the things we come in contact with every day, what will be the object that unlocks the mysteries of mankind in the 21st century?
It is doubtful that any of these questions were weighing on the mind of a random Danish woman in 3700 BCE when she got a hankering for some Stone Age chewing gum. And yet, that wadded-up piece of gum would end up being not only her legacy, but the legacy of her people.
In a new study published in Nature Communications, researchers from the University of Copenhagen shared the news that, for the first time, a complete human genome has been reconstructed from a “non-human material.”
“This is the first time we have the complete ancient human genome from anything other than [human] bone, and that in itself is quite remarkable,” said Hannes Schroeder, an associate professor of evolutionary genomics at the University of Copenhagen’s Globe Institute and a co-author of the study, in a statement. “What’s so exciting about this material is that you can also get microbial DNA.”
The “gum” that was analyzed was a small wad of birch pitch, a sticky substance produced by heating birch bark that had been used as a sort of glue since Paleolithic times. At archaeological sites pieces of it are often found with teeth marks; researchers believe humans chewed it to keep it malleable so it could be used as an adhesive for making tools. Researchers also believe it was also used for many other purposes: Its mild antiseptic qualities could have made it useful for oral health, and it might have been used just as we use chewing gum today.
From the prehistoric gum, researchers learned that “Lola” (as they named the gum-chewer) was lactose intolerant and—just like more than half of Americans today—suffered from periodontal disease. By studying the DNA of the countless oral microbiomes she left behind, they were able to determine that she had recently eaten a meal of duck and hazelnuts before popping history’s most consequential piece of gum (perhaps to freshen up after dinner?).
Radiocarbon dating showed that the pitch was chewed near the advent of the Neolithic period in Denmark, when the lifestyle of hunting and gathering was gradually being replaced by the introduction of agriculture from peoples to the south. Lola’s genome showed no markers that would have associated her with the farming societies that were growing in northern Europe at the time, suggesting that Denmark’s ancient hunter-gatherer populations survived longer than previously thought.
Next time you decide to grab a piece of Big Red, keep in mind that it’s a decision that could end up speaking for all your fellow humans. Your gum is telling future generations a story: They’ll know what you ate, they’ll know what you drank, and they’ll be judging you for “forgetting” to floss.