For the first time, archaeogeneticists used 5,700-year-old saliva to sequence the complete human genome of an ancient hunter gatherer, as well as the world of microbes that lived inside her.
IMAGE BY TOM BJÖRKLUND
Thanks to the tooth marks she left imprinted in ancient ‘chewing gum’, archaeogeneticists were able to obtain DNA, which they used to decipher her genetic code
PHOTOGRAPH BY THEIS JENSEN
“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”. “What’s so exciting about this material is that you can also get microbial DNA”.
hannes schroder, Associate professor of evolutionary genomics at the University of Copenhagen and a co-author of the study.
Where was it found?
The ‘chewing gum’ – really pitch from the birch tree – was discovered at Syltholm on Lolland, an island of Denmark in the Baltic Sea.
Lola lived on the island around 5,700 years before present, so approximately 3,700 B.C. She was lactose intolerant and may have suffered from gum disease. The genetic signatures of hazelnut and mallard duck were also identified within the ‘gum’, suggesting these food sources were part of her diet.
The researchers also extracted DNA from microbes trapped in the ‘chewing gum’. They found pathogens that cause glandular fever and pneumonia, as well as many other viruses and bacteria that are naturally present in the mouth, but don’t cause disease.
The pitch or tar, produced by heating birch bark, has been used to fasten stone blades to handles in Europe since at least the Middle Pleistocene (approximately 750,000 to 125,000 years ago)
“To be able to recover these types of ancient pathogen genomes from material like this is quite exciting because we can study how they evolved and how they are different to strains that are present nowadays. and that tells us something about how they have spread and how they evolved.”
dr schroeder
Like many ancient European hunter-gatherers, she was likely blue-eyed with dark skin and hair
“It is the biggest Stone Age site in Denmark and the archaeological finds suggest that the people who occupied the site were heavily exploiting wild resources well into the Neolithic, which is the period when farming and domesticated animals were first introduced into southern Scandinavia” .
theis jensen, university of copenhagen
Archaeogenetics, a term coined by Colin Renfrew, refers to the application of the techniques of molecular population Genetics to the study of the human past. This can involve:
- the analysis of DNA recovered from archaeological remains, i.e. Ancient DNA;
- the analysis of DNA from modern populations (including humans and domestic plant and animal species) in order to study human past and the Genetic legacy of human interaction with the biosphere; and
- the application of statistical methods developed by molecular Geneticists to archaeological data.
The research is published in the journal Nature Communications.