More than 5700 years ago, a girl spat out a wad of chewing gum at what is now an archaeological site in Denmark. Today, researchers report in Nature Communications that they have sequenced a full genome from that gum, the first time they have extracted so much information from anything other than ancient bones or teeth. Although no human remains have been found at the site of Syltholm, archaeologists found a wad of gum from birch pitch. The DNA in the gum was so well preserved that researchers were able to offer a glimpse of the girl who had chewed it and a snapshot of her life.
The child (artist’s depiction above) had black hair, blue eyes, and dark skin, and was more closely related to hunter-gatherers from Western Europe than to farmers who had more recently settled in the region. She left traces of her most recent meal in the gum—she had been chewing hazelnuts and duck. But her oral microbiome also revealed that life could be hard—she had the Epstein-Barr virus and probably had suffered from mononucleosis in her life. Last year, researchers got some genetic sequences from even older gum from Scandinavia. As predicted, such wads now are becoming a useful resource for researchers.