Saturday, September 15th 2012, 6:10 AM EDT
A study of ancient volcanic ash found at key archaeological sites across Europe suggests that early modern humans were more resilient to climate change and natural disasters than commonly thought. The study, which appeared in PNAS, analyzed volcanic ash from a major eruption that occurred in Europe around 40,000 years ago. The volcano spewed so much ash that the event probably created winter-like conditions and a sudden colder shift in climate. Scientists have generally suggested that the spread of modern humans, and the decline of our cousins the Neanderthals, was primarily due to ancient volcanic eruptions and deteriorating climate conditions, but this study shows that stone-age man rolled with the punches and shrugged off the sudden shifts in climate. This new evidence flies in the face of modern predictions that a shift of a few degrees in average yearly temperature will decimate human populations world wide.
The Response of Humans to Abrupt Environmental Transitions (RESET) project is a research initiative launched in 2008 and funded by the Natural Environment Research Council (UK). It brings together archaeologists, vulcanologist, geochemists, oceanographers and paleontologists to investigate the chronology of major phases of human dispersal and development in Europe and North Africa during the past 100,000 years and examine the degree to which these phases were influenced by abrupt environmental transitions (AETs). RESET funded the paper, “Volcanic ash layers illuminate the resilience of Neanderthals and early modern humans to natural hazards,” by John Lowe et al. that appeared in the July 23 issue of PNAS. Here is a summary of the authors' motivation and findings:
Marked changes in human dispersal and development during the Middle to Upper Paleolithic transition have been attributed to massive volcanic eruption and/or severe climatic deterioration. We test this concept using records of volcanic ash layers of the Campanian Ignimbrite eruption dated to ca. 40,000 y ago (40 ka B.P.). The distribution of the Campanian Ignimbrite has been enhanced by the discovery of cryptotephra deposits (volcanic ash layers that are not visible to the naked eye) in archaeological cave sequences. They enable us to synchronize archaeological and paleoclimatic records through the period of transition from Neanderthal to the earliest anatomically modern human populations in Europe. Our results confirm that the combined effects of a major volcanic eruption and severe climatic cooling failed to have lasting impacts on Neanderthals or early modern humans in Europe. We infer that modern humans proved a greater competitive threat to indigenous populations than natural disasters.
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