Scientists Sequenced a Stone Age Woman From Her Chewing Gum

A blackish-brown lump no bigger than a thumbnail spent 5,700 years buried in Danish mud. When archaeologists pulled it out of the Syltholm site on the island of Lolland in 2016, it looked like nothing special. Then a team led by Theis Jensen at the University of Copenhagen put it through a DNA sequencer and rewrote what a piece of rubbish could tell us.

A Genome From Spit

The lump was birch pitch, a tar-like substance made by heating birch bark. Mesolithic people chewed it to soften it into glue for tool-making, and likely to soothe toothache or just pass the time. Teeth marks were still visible. Locked inside those marks was a complete ancient human genome, the first ever recovered from anything other than bone or teeth.

Meet Lola

The researchers nicknamed her Lola, after Lolland. Her DNA showed she was female, with a combination of traits that modern Europeans rarely picture together: dark skin, dark brown hair, and striking blue eyes. The same phenotype has turned up in other Mesolithic European hunter-gatherers, suggesting it was the norm before farming arrived. She was also lactose intolerant, which fits a population that had not yet domesticated dairy cattle.

A Snapshot of Her Last Meal

The pitch preserved more than her. Inside it, scientists identified DNA from mallard duck and hazelnut, most likely from something she had eaten just before she started chewing. They also pulled out her oral microbiome, including bacteria linked to pneumonia and the Epstein-Barr virus. A single discarded wad gave up a meal, a medical chart, and a face.

Caught at a Turning Point

Syltholm dates to the moment farming was arriving in southern Scandinavia, yet Lolas genome carried no trace of Neolithic farmer ancestry. She was a hunter-gatherer living through the transition, not part of the incoming farming wave. Forensic artists used her DNA profile to reconstruct her face, turning a 5,700-year-old piece of gum into a portrait.