The genetics of a young child who died over 2,000 years ago in what is now South Africa is helping change our understanding of human evolution. The results show that some modern human groups within Africa split at least 260,000 to 350,000 years ago, meaning that our own species has to have evolved at some point before then.
This challenges the established timeline of our species, based on fossil evidence, which has for a long time said that Homo sapiens evolved at some point around 200,000 years ago in East Africa. It also suggests that if humans did live in southern Africa around 300,000 years ago, they were likely living alongside other hominins that are also known to have been in the region, such as the famous Homo naledi discovered a few years ago.
This latest genetic research, published in Science, has only been possible by the incredible advancements seen in recent years in the ability to extract DNA from bones found in warmer and more humid environments. This is now enabling researchers to study the fossils of hominins found in regions of Africa that until now it was thought impossible for genetic material to survive in.
The team sequenced the genomes from seven individuals, all of which were from Southern Africa, with three dating to between 2,300 and 1,800 years ago, and four who lived around 500 to 300 years ago. They found that while the DNA of the younger remains showed evidence of admixture between different human populations, the genetics of a young boy who died some 2,000 years ago did not, and showed that his last common ancestor with other African groups was around 300,000 years ago.
The findings of this latest study rather wonderfully backs up a recent explosive discovery from North Africa, in which researchers revealed they had found the fossils of modern humans dating back at least 300,000 years. This was 100,000 years before it has traditionally been thought humans first evolved in East Africa, not to mention in a completely different region of the continent.
The team involved in that work suggested that it seemed more and more likely that there was no single place in which humans first evolved, but that our species cropped up in multiple regions then each population mingled with each other, something that the scientists from this new study concur with.
“Thus, both palaeo-anthropological and genetic evidence increasingly points to multiregional origins of anatomically modern humans in Africa,” explained Carina Schlebusch. “I.e. Homo sapiens did not originate in one place in Africa, but might have evolved from older forms in several places on the continent with gene flow between groups from different places.”