Ancient human remains are rare and do not necessarily contain DNA
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It was an ordinary day in 2015 when Vivian Soulon had an unexpected moment. She was working at her computer when the results showed that the sample she was examining contained human DNA. That in itself wasn’t all that unusual. At the time, the ancient DNA (aDNA) revolution was in full swing, and amazing new insights about our ancestors were slowly being revealed. However, Sulong’s sample was not from human remains, but simply soil taken from the cave floor. It immediately told her that she was onto something big.
Many archaeological sites have unearthed tools and artifacts that testify to human occupation, but few offer bones or teeth that may still contain human aDNA. Even if such remains exist, there is little chance of any genetic material surviving in them, since DNA is damaged by heat, moisture, and acidity. So finding another source of aDNA – the soil itself – was a game-changer. “This will reveal hundreds of prehistoric sites that we couldn’t work with before,” Slon says.
Moreover, humble dirt can reveal a lot about our distant past. Fossils provide a snapshot of prehistory, while sediments provide a source of DNA that could, in theory, produce an unbroken story. Researchers can study humans before burials took place. They can uncover which groups created particular tools and other artifacts and learn more about them cognitively and artistically.
