These early humans survived a supervolcano eruption 74,000 years ago

[Judi Lynn]

Striking evidence means the “Toba Catastrophe Theory” is headed for the dustbin.
ANNALEE NEWITZ - 3/20/2018, 4:19 PM

It's one of the biggest mysteries of recent human evolution. Roughly 70,000 years ago, Homo sapiens went through a genetic bottleneck, a period when our genetic diversity shrank dramatically. But why? In the late 1990s, some scientists argued that the culprit was a massive volcanic eruption from what is now Lake Toba, in Sumatra, about 74,000 years ago, whose deadly effects reduced our species to a few thousand hardy individuals. Now, new evidence suggests we were right about the volcano—but wrong about pretty much everything else.

The so-called Toba Catastrophe Theory was first proposed by University of Illinois anthropologist Stanley Ambrose and popularized by University of Utah anthropologist Henry Harpending, who was trying to understand what caused the genetic bottleneck. At the time, mounting evidence suggested that the volcano had had a global effect, because debris from it can be found throughout the world. Many scientists thought it was likely that airborne particles from Toba caused a "volcanic winter" that lowered Earth's temperatures. Harpending and his colleague Gregory Cochran suggested that it ushered in a millennium of frigid temperatures, driving humanity to near-extinction and pushing it out of Africa in search of better habitats.

Once the globe warmed up again, the theory goes, humanity started to recover its ranks. But the population crash meant that we had lost a lot of genetic diversity. This hypothesis sounded reasonable at first, but then scientists began to uncover intriguing new evidence that humans hadn't died out at all.

The catastrophe that wasn’t
A paper published last week in Nature explores much of that evidence and presents a coup de grâce discovery that debunks the Toba Catastrophe Theory. That discovery comes from two beautifully preserved ancient campsites at the very southern tip of South Africa. There, in a cozy rock shelter and an open campsite, humans lived through the Toba eruption and thrived afterwards. University of Nevada, Las Vegas, geoscientist Eugene Smith worked with an international team of researchers to analyze the sites, digging down through many layers of habitation to see exactly what happened in the years following the supposed catastrophe.

More:
https://arstechnica.com/science/2018/03/ancient-campsite-shows-humans-surviving-a-massive-volcanic-eruption/

[elfin]

1. I always learn something from your posts. Thank You. nt

[Judi Lynn]

2. We're learning at the same time, elfin! Thank you, so much. n/t