Ancient DNA has revealed remarkable details about human history, especially in Europe and Asia, where scientists have successfully reconstructed the genomes of thousands of individuals. In contrast, there have been fewer than twenty ancient genomes documented from southern Africa, particularly from Botswana, South Africa, and Zambia. This area is home to some of the earliest signs of modern humans, with the oldest genomes dating back approximately 2,000 years.
A collaborative team from the University of Cape Town in South Africa and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, has studied human remains from the Oakhurst rock shelter, located in the southern part of Africa. They managed to reconstruct the genomes of thirteen individuals who lived between 1,300 and 10,000 years ago, including the oldest human genome recorded in South Africa so far.
“The Oakhurst rock shelter serves as a prime location for exploring human history, containing over 40 human graves along with layers of preserved artifacts like stone tools that date back 12,000 years,” explains Victoria Gibbon, a Professor of Biological Anthropology at the University of Cape Town and one of the study’s co-senior authors. “Such sites are uncommon in South Africa, and Oakhurst has enhanced our understanding of population movements and relationships in the area over nearly 9,000 years.”
Long history of genetic stability in southernmost Africa
Sequencing the genomes of thirteen individuals from this site posed several challenges, as noted by Stephan Schiffels, the study’s co-senior author: “Extracting and processing such ancient and poorly preserved DNA is quite complex, and we had to make several attempts using various technologies and lab protocols.” These ancient genomes provide a timeline from 10,000 to 1,300 years ago, offering a rare chance to explore human migrations over time and their connection to the diverse groups inhabiting the region today.
One notable discovery was that the oldest genomes from the Oakhurst shelter show a strong genetic similarity to the San and Khoekhoe populations currently residing in the area. This finding was unexpected, as Joscha Gretzinger, the lead author, points out: “Unlike studies from Europe, which have shown significant genetic changes from human movements in the last 10,000 years, our results from southernmost Africa suggest a prolonged period of relative genetic stability.” This stability began to shift around 1,200 years ago, coinciding with the arrival of new groups who brought pastoralism, agriculture, and new languages, leading to interactions with local hunter-gatherers.
In one of the world’s most culturally, linguistically, and genetically diverse regions, this new research indicates that South Africa’s extensive archaeological heritage is becoming more accessible for archaeogenetics, yielding fresh insights into human history and demographics from the past.
