Saturday, March 28, 2015

Did a Volcanic Eruption Kill Off the Neandertals? Science Determines: Sorta

Is "sorta" an appropriately scientific conclusion?

In this case yes.

Most people think that competition between homo sapiens and Neandertals finally brought an end to that fascinating species.  Well, sorta.

It seems that there was a volcano that went off in a massive eruption some 40,000 years ago.  It would be easy to conclude that this eruption put the nail in the Neandertals' coffins, but according to this research, the eruption didn't help, but wasn't the final blow to their survival.

What seems to have had more of an impact was climate change that resulted from the huge insertion of a gas, sulfur dioxide, into the atmosphere.  Where it cooled the atmosphere.

"The roles of climate, hominin competition,
and volcanic sulfur cooling and acid deposition
are debated as causes of Neandertal extinction."

So there is no agreement in the scientific community about the final demise of the Neandertals.

For a writer of pre-historical fiction, an understanding of what actually happened would seem to be important. 

A study published in the professional journal, Geology, examines the effects of this eruption on the climate of Europe at the time of the Neandertal extinction.  Their conclusion?  Neither the eruption nor the cooling of the environment helped.


Did a volcanic cataclysm 40,000 years ago
trigger the final demise of the Neandertal?

About 39,000 years ago, Europe experienced the largest volcanic
eruption in the last 200,000 years. This super-eruption may have
played a part in wiping out or driving away Neanderthal and
modern human populations in the eastern Mediterranean.
The Campanian Ignimbrite (CI) eruption in Italy of the Campi Plegri super vocano west of present day Naples 40,000 years ago was one of the largest volcanic cataclysms in Europe.  The eruption injected a significant amount of sulfur-dioxide (SO2) into the stratosphere. Scientists have long debated whether this eruption contributed to the final extinction of the Neanderthals. This new study by Benjamin A. Black and colleagues tests this hypothesis with a sophisticated climate model.

Black and colleagues write that the CI eruption approximately coincided with the final decline of Neanderthals as well as with dramatic territorial and cultural advances among anatomically modern humans. Because of this, the roles of climate, hominin competition, and volcanic sulfur cooling and acid deposition have been vigorously debated as causes of Neandertal extinction.

Decline of the Neandertal in Europe
image
Fallout zone of the Campanian Ignimbrite eruption
They point out, however, that the decline of Neandertals in Europe began well before the CI eruption: "Radiocarbon dating has shown that at the time of the CI eruption, anatomically modern humans had already arrived in Europe, and the range of Neandertals had steadily diminished. Work at five sites in the Mediterranean indicates that anatomically modern humans were established in these locations by then as well."




"While the precise implications of the CI eruption for cultures and livelihoods are best understood in the context of archaeological data sets," write Black and colleagues, the results of their study quantitatively describe the magnitude and distribution of the volcanic cooling and acid deposition that ancient hominin communities experienced coincident with the final decline of the Neandertals.

Eruption effects miss the neandertal
In their climate simulations, Black and colleagues found that the largest temperature decreases after the eruption occurred in Eastern Europe and Asia and sidestepped the areas where the final Neandertal populations were living (see map to right). Therefore, the authors conclude that the eruption was probably insufficient to trigger Neandertal extinction. 
The Neanderthals
Rediscovered:
How Modern Science Is
Rewriting Their Story
by Dimitra Papagianni

Click on image to order

"Temperatures in Western Europe would have decreased
2 to 4 degrees Celsius during the year following the eruption."

Ah, but the cold spell
However, the abrupt cold spell that followed the eruption would still have significantly impacted day-to-day life for Neanderthals and early humans in Europe. Black and colleagues point out that temperatures in Western Europe would have decreased by an average of 2 to 4 degrees Celsius during the year following the eruption. These unusual conditions, they write, may have directly influenced survival and day-to-day life for Neandertals and anatomically modern humans alike, and emphasize the resilience of anatomically modern humans in the face of abrupt and adverse changes in the environment.

So the definitive answer is: sorta

Related stories:
Also:
  • DNA Research Shows a Mystery Population Invented Agriculture
  • Farming culture traveled to Europe by boat, not overland
  • Here, kitty, kitty, kitty. Humans met sabre-tooth cats 300,000 years ago
  • How Our Stone Age Ancestors Lived & Hid
  • The Killing Advantage of Stone Tipped Spears
  • Oldest fortified settlement ever found in North America
  • The Quest for Fire, Revisited
  • The Unknown Volcanic Eruption of 1808 & Mary Shelley's Frankenstein

  • *  *  *  *  *
    Story Source:  Materials provided by Geological Society of America. B. A. Black, R. R. Neely, M. Manga. Campanian Ignimbrite volcanism, climate, and the final decline of the Neanderthals. Geology, 2015.