Researchers in Denmark have squeaked out an entire human genome from a prehistoric piece of “chewing gum.” Made from birch tar, the 5,700-year-old gum also contained evidence of diet and disease and is providing a remarkable snapshot of life during the early Neolithic.
A team led by Hannes Schroeder from the University of Denmark sequenced the human DNA found within a specimen of pitch, and determined that it was from a female and, based on genetic variation in several genes, that she likely had dark hair, dark skin and blue eyes.
Writing in the journal Nature Communications, they suggest Lola was more closely related to western hunter-gatherers from continental Europe than hunter-gatherers from central Scandinavia.
Birch pitch is obtained by heating birch bark and it has been used as an adhesive since the Middle Pleistocene (approximately 760,000 to 126,000 years ago). Small lumps of it have been found at archaeological sites and have often included tooth imprints, suggesting they were chewed.
In the non-human ancient DNA found in their specimen, Schroeder and colleagues detected bacterial species characteristic of the oral microbiome, some of which are known pathogens such as Porphyromonas gingivalis, which are implicated in gum disease.
In addition, they say, DNA sequences could be mapped to plant and animal species such as hazelnut and mallard, which the authors propose were left over from a recent meal.