Modern humans survived because they lived in Africa and on the tip of southwestern Asia at that time, safely outside the range of volcanic ash clouds, Golovanova's group proposes in the October Current Anthropology. If that scenario pans out, then geographic good luck allowed Homo sapiens to move into Neandertals' former haunts after a couple thousand years without having to compete with them for food and other resources, as many researchers have assumed.
Advances in stone toolmaking and other cultural innovations achieved by modern humans shortly after 40,000 years ago supported survival in harsh, postvolcanic habitats, Golovanova and his colleagues hypothesize.
"For the first time, we have identified evidence that the disappearance of Neandertals in the Caucasus coincides with a volcanic eruption approximately 40,000 years ago," Golovanova says.
His new study focuses on soil, pollen, animal bones and stone tools from Mezmaiskaya Cave in southwestern Russia's Caucasus Mountains. Excavation of this cave began in 1987.
In a comment published along with the new study, archaeologist Paul Pettitt of the University of Sheffield in England agrees that Neandertals disappeared at Mezmaiskaya Cave and its surrounding region shortly after volcanic eruptions identified by Golovanova's team. But the timing of Neandertal and modern human occupations over at least 10,000 years in an area covering tens of thousands of square kilometers in Europe and Asia remains poorly understood, Pettitt cautions.
Chemical analyses of soil layers in the Russian cave identified two types of volcanic ash denoting separate volcanic eruptions in western Asia between 45,000 and 40,000 years ago. Plant pollen recovered in the cave indicates that extremely cold, dry conditions prevailed around the time these ash layers formed.
Read more at Discovery News
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