Ancient DNA extracted from a deer tooth pendant has revealed that the age-old jewelry was worn by a single female owner between 19,000 and 25,000 years ago. Found in the famous Denisova Cave in Russia, the trinket belonged to a woman with strong genetic ties to a group of humans that lived further east in Siberia.
Stone Age artifacts hold vital secrets about ancient societies and are essential to our understanding of how humans lived during prehistory. Unfortunately, though, these items can rarely be linked to specific individuals since they are seldom found alongside actual human remains from the deep past.
To overcome this hurdle, researchers have now developed a technique to extract DNA from skeletal artifacts without damaging them. Describing their work in a new study, the authors explain that items made from teeth or bones are more porous than those crafted from stone, and are therefore more likely to harbor and retain ancient human body fluids.
The non-destructive method involves submerging the items in a sodium phosphate buffer while slowly raising the temperature, allowing DNA trapped within the pores to emerge. “One could say we have created a washing machine for ancient artifacts within our clean laboratory," said study author Elena Essel in a statement.
"By washing the artifacts at temperatures of up to 90°C [194°F], we are able to extract DNA from the wash waters, while keeping the artifacts intact.”
The researchers used their technique to obtain genetic material from a deer tooth pendant that had been discovered in the Denisova Cave in 2019. Famous for harboring evidence of an ancient human species known as the Denisovans, the cave was also home to Neanderthals and modern humans throughout prehistory.
In addition to extracting genetic material from the wapiti deer from which the item was made, the researchers also uncovered traces of the human who made, handled, or wore the pendant. “The amount of human DNA we recovered from the pendant was extraordinary,” said Essel. “Almost as if we had sampled a human tooth.”
Examining the mitochondrial DNA obtained from the artifact, the study authors concluded that most of this genetic material belonged to a single individual. The human and wapiti genomes also allowed the researchers to estimate the age of the pendant without the need for destructive radiocarbon dating.
According to their results, the piece was made and used between 19,000 and 25,000 years ago.
An analysis of the nuclear DNA extracted from the pendant revealed that the ancient owner had a high genetic affinity with modern-day Native Americans. When comparing this material to other ancient genomes, the researchers discovered that the wearer of the pendant was strongly related to a prehistoric human group called the Ancient North Eurasians. Traces of this lineage have previously been found in caves further east in Siberia and dated to between 17,000 and 24,000 years ago.
“In summary, our work highlights that artefacts made from bones or teeth are a previously untapped source of ancient human DNA that can provide insights about the ancestry and biological sex of the individuals who handled, carried or wore these objects in the deep past,” conclude the study authors.
The study is published in Nature.