Ancient tools found in India suggest the Toba supervolcano eruption didn't leave humanity on the brink of extinction

Standing on the Dhaba site, overlooking the Middle Son Valley, India. Note the archaeological trench location on the left hand side of the photo.Christina Neudorf

  • Ancient tools discovered in northern India provide new evidence that humans were able to survive one of the largest volcanic events in human history — the Toba supervolcano eruption.
  • The Toba catastrophe theory states that the eruption covered South Asia in ash and blackened out the skies triggering an ice age, leaving only a dwindling human population in its wake.
  • However, mounting archaeological evidence suggests that humans may have persevered.
When the Toba supervolcano erupted 74,000 years ago, it was one of the most devastating events to ever hit the planet, thought to have brought humanity on the brink of extinction — or so we thought.

Ancient tools discovered in Dhaba northern India punch another hole Toba catastrophe theory and add to the piling evidence that the event wasn’t as extreme as scientists previously assumed.

Stone tools found at the Dhaba site corresponding with the Toba volcanic super-eruption levels. Pictured here are diagnostic Middle Palaeolithic core types.Chris Clarkson


The Toba catastrophe theory states that the massive eruption — 100 times greater than the biggest explosion in recent history, the 1815 eruption of Mount Tambora — only left a few thousand survivors in its wake. The fall-out triggered a decade of volcanic winter and an ice-age that lasted a millennium.

However, the study of stone tools published in Nature Communications suggests that humans were present in the Middle Son Valley 80,000 years before and after the volcano erupted.

Key artefact types at Dhaba<br>Clarkson et al., Nature Communications

"Although Toba ash was first identified in the Son Valley back in the 1980s until now we did not have associated archaeological evidence, so the Dhaba site fills in a major chronological gap," said principal investigator J.N. Pal.

Ashes to ashes, dust to dust — the Toba catastrophe theory
The Toba catastrophe theory is one of correlation. Around the same time as the eruption in present-day Indonesia, humanity was in a bit of rut with respect to evolution.

Clarkson et al., Nature Communications, 2019

The sky was blacked out, most of South Asia and the Indian Ocean was covered in 15 centimetres-thick layer of ash, and humanity was dying out.


Since both events seem to coincide, scientists theorised that the supervolcano was a plausible reason for the sudden drop in diversity. However, with new data coming into the picture, the pieces are no longer adding up.

Reasonable doubt
The first evidence to refute the theory came to light in 2007. Evidence of stone tools in southern India suggested that humans existed during the time period. However, according to the Toba catastrophe theory the only surviving humans were in Africa — who later populated Asia 60,000 years ago.

A fossil found in South Africa cast further doubt. Discovered in 2018, the archaeological evidence suggested that the global human not only survived the eruption but thrived.


Human resilience
Scientists still agree that there was a drop in diversity around 70,000 years ago. However, some no longer believe it was due to the supervolcano triggering climate change.

A few theorise that it’s simply the founder effect — the loss of genetic variation when small groups break off from a large population, but they’re not genetically representative. As a result, the population is vulnerable to genetic drift and inbreeding.

More data is needed to fill the gaps of Earth’s timeline, but these new ancient tools suggest that humans were able to survive one of the largest volcanic events in human history.


See also:
The weathering Himalayas might not be behind Earth's cooling over the past 15 million years

NASA has a $3.5 billion idea to save Earth from a supervolcano apocalypse