5700 years ago, a woman lived in what is now Denmark, chewed a piece of tree bark and then spat. Millennia later, the DNA she left behind, in addition to revealing her entire genome, allowed to map details about her daily life.
Sequencing was carried out by researchers at the University of Copenhagen, who released the feat on Thursday (13). It was through a “prehistoric gum,” a sap found in birch bark, then used to clean the teeth, that scientists understood Lola —as the human ancestor was named.
She had blue eyes, brown hair and dark skin. “This combination of physical characteristics has already been observed in other European groups, suggesting that this phenotype was widespread in Europe and that the adaptive dissemination of clear skin pigmentation in populations only occurred later,” the research describes.
But far beyond physical details and genuinely European DNA, the place where it was found revealed archaeological evidence of being an agricultural settlement, suggesting that her ethnic group had absorbed habits of societies in formation in Eurasia – where first humans dominated agriculture.
Lola’s DNA wasn’t the only one found on gum, as a small percentage came from other things she had chewed: a hazelnut and a kind of duck. The information suggests that even after lola’s community learned to cultivate, the group still depended on wild foods. Duck bones and hazelnuts, found at the site, reinforce the evidence.
Lola’s genome also contains alleles that are usually associated with the inability to produce lactase – an important enzyme in milk digestion – as an adult. If lactose intolerance was still common among people in Scandinavia shortly after the Neolithic revolution (the wave of migration and cultural change that introduced agriculture in most of Europe), evidence shows that Europeans probably evolved in the ability to drink milk as adults only after dairy farming became a common way of life, a fact that occurred a few thousand years ago.
Lola’s genome also tells archaeologists about the first people to move to Scandinavia after the ice sheets receded between 12,000 and 11,000 years ago, generations before our ancestor dwelled in Denmark. Based on other archaeological and genetic evidence, it was possible to cross the data to conclude that, after the ice retraction, people from different areas of Eurasia moved to Scandinavia by two routes. Some hunter-gatherers from continental Europe moved north through Denmark (the descendants of Lola), while others, from the northeast, moved south along the coast of Norway.
Research is a sample of the giant contribution genetics can have on the discoveries of the past. Without saying anything, Lola’s mouth detailed part of the fragmented history of mankind.