Scientists have extracted ancient human DNA from a 20,000-year-old elk's canine tooth – pierced to become a pendant – unearthed inside a Siberian cave that has been an archaeological treasure trove.
The new collection of pendants from Denisova Cave paid dividends. Scientists on Wednesday said a new method for extracting ancient DNA identified the object's long-ago owner – a Stone Age woman closely related to a population of hunter-gatherers known to have lived in a part of Siberia east of the cave site in the foothills of the Altai Mountains in Russia.
The method can isolate DNA present in skin cells, sweat or other bodily fluids and be absorbed by certain types of porous material, including bones, teeth and tusks, when handled by someone thousands of years ago.
Objects used as tools or for personal adornment – pendants, necklaces, bracelets, rings and the like – can offer insight into past behavior and culture. However, our understanding has been limited by an inability to tie a particular object to a specific person.
"I find these objects made in the deep past extremely fascinating since they allow us to open a small window to travel back and have a glance into these people's lives," said molecular biologist Elena Essel of the Max Planck Institute for Evolutionary Anthropology in Germany, lead author of the study published in the journal Nature.
The researchers who found the pendant, determined to be 19,000-25,000 years old, used gloves and face masks when excavating and handling it, avoiding contamination with modern DNA. As a result, it became the first prehistoric artifact linked by genetic sleuthing to a specific person. However, it is unknown whether the woman made or merely wore it.
Essel said she held such an artifact in her gloved hands; she felt "transported back in time, imagining the human hands that had created and used it thousands of years ago."
"As I looked at the object, a flood of questions came to mind. Who was the person who made it? Was this tool passed down from one generation to the next, from a mother to a daughter or from a father to a son? That we can start addressing these questions using genetic tools is still incredible to me," Essel added.
The pendant's maker drilled a hole in the tooth for some now-lost cordage. The tooth alternatively could have been part of a headband or bracelet.
The oldest-known objects used as personal adornments date to about 100,000 years ago from Africa, according to the University of Leiden's Marie Soressi, the study's senior archaeologist.
Denisova Cave has yielded remarkable finds over the years, including various tools and other artifacts.
The new nondestructive research technique, used at Leipzig's "clean room" laboratory, works much like a washing machine. In this case, an artifact is immersed in a liquid that works to release DNA from it, much as a washing machine lifts dirt from a blouse.
By linking objects with particular people, the technique could shed light on prehistoric social roles and the division of labor between the sexes.
"This study opens huge opportunities to better reconstruct the role of individuals in the past according to their sex and ancestry," Soressi said.
