A major new study has revealed that a group of people in southern Africa lived in partial isolation for hundreds of thousands of years—offering powerful new insights into how modern humans evolved.
Researchers analyzed the genomes of 28 individuals who lived between 10,200 and 150 years ago and found evidence that southern Africa played a central role in shaping Homo sapiens.
The study, the largest ever conducted on ancient African DNA, was published in Nature.
Modern humans have existed for at least 300,000 years, but exactly where our species first emerged has been debated.
Many earlier theories suggested that humans evolved in eastern Africa and only moved south much later. The new findings challenge this idea.
According to lead researcher Mattias Jakobsson of Uppsala University, the DNA clearly shows that Homo sapiens lived and evolved in southern Africa for a very long time, making the region one of the most important in human evolutionary history.
The researchers compared the genomes of these ancient individuals with genetic data from people across Africa and the world.
They discovered that the Stone Age population of southern Africa had been genetically separate from other human groups for at least 200,000 years. It was only around 1,400 years ago that DNA from groups in East and West Africa began to appear in the region.
Even though no large migrations moved into southern Africa before then, some members of the southern group did move north during favorable climate periods.
Traces of their genetic material appear in individuals who lived in present-day Malawi around 8,000 years ago.
Many of the remains used in the study were found at the Matjes River Rock Shelter in South Africa, where archaeological layers show changing tool-making styles over thousands of years.
Despite these cultural shifts, the individuals themselves were genetically almost identical across the entire period. This suggests that new technologies developed locally rather than arriving with new groups of people, unlike in Europe, where cultural change often followed migration.
The study identified 79 genetic variants unique to Homo sapiens and not found in Neanderthals, Denisovans, or other primates. These variants appear in all modern humans and likely played key roles in our evolution.
Remarkably, many of them affect kidney function. Researchers believe these changes may have supported humans’ unique ability to cool themselves by sweating, which depends on finely controlled water balance in the body.
Other variants were linked to the immune system, brain development, and cognitive abilities, including genes associated with attention and neuron growth.
Around 80 percent of the genetic material found in the ancient individuals still exists today in modern San communities, such as the Ju/’hoansi and the Karretjie people. These findings show that the prehistoric population of southern Africa was both large and stable, rather than a small group spread across the continent as previously thought.
The researchers say these ancient genomes are helping to create the clearest picture yet of early human evolution in Africa.
As more high-quality DNA samples are studied, our understanding of where we come from continues to become richer and more detailed.
