Scientists have discovered DNA from the Stone Age, but their findings were “more complicated” than initially expected and raised more questions than answers. Archaeologists were studying the ancient Shum Laka rock shelter (pictures can be seen here) located in northwestern Cameroon when they found Stone Age DNA belonging to a mysterious “Ghost Tribe”. This previously unknown population was among the earliest settlers in Africa.
In an interview with National Geographic magazine, Mary Prendergast, who is an anthropologist at Saint Louis University in Madrid, explained the complexity of studying ancient genomes from West Africa by saying, “It’s always more complicated than once thought,” adding, “You can go in with one set of questions and come out with a very different set of answers that raises a whole new set of questions.”
The Stone Age DNA was taken from the graves of four children – a 4-year-old boy and a 15-year-old boy from approximately 8,000 years ago, as well as a 4-year-old girl and an 8-year-old boy from around 3,000 years ago. Although they lived thousands of years apart, the four children were all related (distant cousins).
Upon analysis, researchers noticed that their DNA was quite similar to the modern-day hunter-gatherer groups found in Central Africa. While one-third of the children’s DNA was related to the hunter-gatherers in western Central Africa, two-thirds came from a second population in western Africa which included a “long lost ghost population of modern humans that we didn’t know about before,” David Reich, who is a population geneticist, told Science Magazine.
At least four major human lineages from 200,000 to 300,000 years ago were confirmed in the DNA. In addition to those, four sub-branches of human lineages from 60,000 to 80,000 years ago were also identified.
And researchers found a lot more than those four graves. They found a total of 18 human burials at the Shum Laka rock shelter in addition to several items including hundreds of bowls and utensils used for cooking. It is believed that this mysterious “Ghost Tribe” inhabited the area for at least 30,000 years.
The researchers’ paper was published in the journal Nature and can be read in full here.