Toba eruption and early humans in India

When Mount Toba erupted some 78,000 years ago, so much ash was released into the atmosphere that the entire Indian sub-continent was smothered in it. To this day the meters thick ash is 'mined' in Jwalapuram in southeastern India. Then, in 2007, a team of archeologists discovered some stone tools were under these levels of ash, suggesting that modern humans reached India at least 78,000 years ago[1]. That, however, was a lot earlier than scientists used to believe. Even professor Alice Roberts heralded the discovery in her television series (2009) and book (2010) 'The Incredible Human Journey'.

[Buy the book here]

But the exitement was short lived, because in 2013 new evidence emerged that refuted that very early date[2]. Scientists collected mitochondrial DNA samples from 817 volunteers all across the Eurasian subcontinent, while also reexamining the stone tools that had originally set off the debate.

In studying the mtDNA, the researchers concluded that modern humans had settled in the area no earlier than 55,000 to 60,000 years ago. The evidence indicated that early humans had settled along the coast first, only then traveled inland following rivers. Such a timeline indicates that modern humans didn't migrate to India untill well after the eruption of Mount Toba.

[Large cutting stone found in the ashes in Jwalapuram]

Meanwhile, other members on the team investigated the stone tools discovered by the earlier team and found that they were very likely the work of Neanderthals, not early modern humans. They note that the author of the original study claiming the stones had been made by early humans had already withdrawn the paper with the suggestion that the tools were likely made by an unidentified group of archaic people living in the area at the time.

Taken together, the team concluded that their findings should once and for all end the debate regarding the migration timeline for modern humans moving into India.

[1] Petraglia et al: Middle Paleolithic Assemblages from the Indian Subcontinent Before and After the Toba Super-Eruption in Science – 2007. See here.
[2] Mellars et al: Genetic and archaeological perspectives on the initial modern human colonization of southern Asia in PNAS – 2013. See here.