Modern humans emerged earlier than previously thought‚ study finds

A research study based on DNA analysis of a Stone Age child who lived in KwaZulu-Natal has found that genetically modern humans emerged much earlier than previously thought‚ and probably in more than one African region.

Researchers from the University of Johannesburg (UJ) and Uppsala University in Sweden co-led the research which appeared on Thursday in the top international research journal Science.

South Africa is well known for its hominin fossil record‚ but the results of the study on the 2000-year-old remains of the boy found at Ballito Bay in KwaZulu-Natal during the 1960s have helped to rewrite human history‚ according to UJ.

Marlize Lombard‚ Professor of Stone Age archaeology at the University of Johannesburg‚ initiated collaboration with geneticists from Uppsala University in Sweden and the University of the Witwatersrand‚ who put together a team of experts at the Uppsala laboratory.

They reconstructed the full genome of the Ballito Bay child‚ together with the genomes of six other individuals from KwaZulu-Natal who lived between 2300 and 300 years ago.

Three Stone Age individuals who lived between 2300 and 1800 years ago were found to be genetically related to the descendants of Khoe-San groups living in southern Africa today. The remains of the other four individuals who lived 500-300 years ago during the Iron Age‚ were genetically related to present-day South Africans of West African descent.

Because the boy from Ballito Bay was of hunter-gatherer descent‚ living at a time before migrants from further north in Africa reached South African shores‚ his DNA could be used to estimate the split between modern humans and earlier human groups as occurring between 350‚000 and 260‚000 years ago.

"This means that modern humans emerged earlier than previously thought"‚ says Mattias Jakobsson‚ population geneticist at Uppsala University‚ who headed the project together with Lombard from the University of Johannesburg.