In the ongoing argument over when modern humans settled Asia, a new study highlighting evidence that the migration from Africa began after the super-eruption of the Mount Toba volcano in Sumatra, Indonesia in 72,000 B.C. was recently published in the Proceedings of the National Academy of Sciences

This is not the first time Richards has argued the recent arrival of humans to Asia: in 2005, Richards led research published in the journal Science that used mitochondrial DNA evidence to demonstrate that anatomically modern humans dispersed from their Africa homeland via a “southern coastal route” from the Horn and through the Middle East about 60,000 years ago.

Just two years later, however, a team of archaeologists reported in the same journal that they had uncovered evidence that modern humans inhabited India as early as 120,000 years ago, placing it much earlier on the timeline in terms of colonization than Europe and even the Middle East.

Now Richards is back and, working alongside Paul Mellars of the University of Cambridge, has drawn on a much larger body of DNA evidence to defend his original statement.

“One of the things we didn’t have in 2005 was very much evidence from India in the way of mitochondrial sequences,” he explained in a press release. “Now, with a lot of people doing sequencing and depositing material in databases there are about 1,000 sequences from India.”

By using the mitochandiral DNA of the modern population and working backwards, and by drawing on a wide variety of other evidence and research, the researchers and their team were able to make much more precise estimates for the arrival of modern humans to the area.

The verdict? Humans arrived no earlier than 60,000 years ago.

To explain the archaeological similarities between African and Indian stone-tool technologies after 70,000, as well as features such as beads and engravings, Richards argues that the slightly later Indian material had an African source.

“There were people in India before the Toba Eruption, because there are stone tools there,” Richards concedes, “but they could have been Neanderthals – or some other pre-modern population.”

Finally, he posits that the replacement of the “presumably archaic humans” living in the region by modern people with their new technologies is evidenced in the replacement of Neanderthals by modern humans in Europe and western Asia between 40,000 and 50,000 years ago.