Modern humans did not leave Africa prior to the massive eruption of Sumatra´s volcano Mount Toba 74,000 years ago, according to a new study appearing in the journal Proceedings of the National Academy of Sciences.
Rather, Professor Martin Richards of the University of Huddersfield and colleagues have concluded that genetic evidence supports the belief that they departed for Asia approximately 60,000 years ago. Their findings refute a recent theory which had suggested that there was archaeological evidence establishing the presence of people in the southern part of the continent prior to the super-eruption, the university said in a statement.
Previous research completed by Richards used mitochondrial DNA evidence to show that anatomically modern men and women departed from Africa via a “southern coastal route” from the Horn and through Arabia some 14,000 years after the eruption of Mount Toba. Since then, however, archaeologists working in India say they had discovered evidence that humans had lived there far earlier — perhaps up to 120,000 years ago.
Those claims were made after the archaeologists discovered stone tools beneath a layer of Toba ash in 2007. In a rebuttal to those claims, Richards, University of Cambridge archaeologist Sir Paul Mellars, and others found additional genetic evidence to support Richards´ previous conclusion.
“One of the things we didn´t have in 2005 was very much evidence from India in the way of mitochondrial sequences. Now, with a lot of people doing sequencing and depositing material in databases there are about 1,000 sequences from India,” Mellars explained.
By using modern mitochondrial DNA and working backwards, Richards and his colleagues were able to make more exact estimates as to when exactly people set foot on the Indian continent. That genetic information, combined with additional evidence and research, led them to conclude that the dispersal from Africa and the settlement in India could have happened no earlier than 60,000 years ago.
“We also argue that close archaeological similarities between African and Indian stone-tool technologies after 70,000 years ago, as well as features such as beads and engravings, suggest that the slightly later Indian material had an African source,” Richards added. “There were people in India before the Toba eruption, because there are stone tools there, but they could have been Neanderthals — or some other pre-modern population.”
The recently-published research is “an unusually strong scientific put-down,” said Lewis Smith of the Daily Mail. He added that the research done by Richards´ team essentially declares that the pre-eruption settlement theory is “worthless,” and that the researchers wrote that they found “no evidence, either genetic or archaeological, for a very early modern human colonization of South Asia, before the Toba eruption.”