Modern humans have walked the Earth for at least 300,000 years

It had previously been estimated that modern humans first emerged in Africa 200,000 years ago. But now, new research has revealed that we may have been around even longer.

Through genome sequencing, researchers have found evidence that modern humans were present on Earth around 350,000 and 260,000 years ago.

The collaborative team of researchers from the Uppsala University in Sweden, and the Universities of Johannesburg and the Witwatersrand in South Africa published their findings in the journal Science.

The team sequenced the genomes of seven individuals who lived in Southern Africa 23,000 to 300 years ago. The youngest of the individuals were genetically related to current-day Bantu-speaking South Africans.

“This illustrates the population replacement that occurred in southern Africa,” said Carina Schlebusch, a population geneticist at Uppsala University and the study’s first author.

Researchers have been able to map the emergence and evolution of modern man over time thanks to key paleontological discoveries of human fossils like the Omo and Herto, some of the oldest ever found.

The east Africa fossil record and the Omo and Herto fossils led researchers to believe that anatomically modern humans were present around 180,000 years ago.

However, this new research from southern Africa indicates that modern humans emerged even earlier.

“It now seems that at least two or three Homo species occupied the southern African landscape during this period, which also represents the early phases of the Middle Stone Age,” said Marlize Lombard, a Stone Age archaeologist at the University of Johannesburg.

The researchers also found that some of the individuals had genes that protected against malaria and sleeping sickness. The older individuals, present during the Stone Age, did not have this disease resistance.

“This tells us that Iron Age farmers carried these disease-resistance variants when they migrated to southern Africa,” said Helena Malmström, one of the study’s co-authors.  

The results of the study also show that Homo sapiens did not originate in one specific place in Africa as previous theories have suggested.

“Thus, both palaeo-anthropological and genetic evidence increasingly points to multiregional origins of anatomically modern humans in Africa, 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,” said Carina Schlebusch.

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By Kay Vandette, Earth.com Staff Writer