Ancient human remains are rare and do not necessarily contain DNA
Shutterstock/Microgen
It was an otherwise ordinary day in 2015 when Viviane Slone had her eureka moment. While working on his computer, the results revealed that the sample he was analyzing contained human DNA. There was nothing inherently strange about it: at the time, the ancient DNA (aDNA) revolution was in full swing, and amazing new insights into our ancestors were slowly being revealed. But Sloan’s sample wasn’t from human remains, it was just dirt from a cave floor. That immediately told him he was on to something big.
Many archaeological sites provide tools and artifacts that tell us about human occupation, but few have yet yielded bones or teeth that may contain human DNA. Even when such remains are present, the chances of the genetic material surviving within them are slim, as DNA is damaged by heat, humidity and acidity. So finding another source of aDNA – the earth itself – was a game changer. “This opens up hundreds of prehistoric sites that we couldn’t work on before,” says Slone.
Also, simple dirt can reveal a lot about our distant past. While fossils provide prehistoric snapshots, sediments provide a source of DNA that can theoretically create an uninterrupted narrative. Researchers can study hominins that predate the practice of burial. They can work out which groups created particular tools and other artifacts, learning more about their cognitive and art…
