MEZMAISKAYA CAVE (Russie) : Volcanoes wiped out the Neandertals ?

Volcanoes wiped out the Neandertals ?

D. Vergano

Source : http://content.usatoday.com/communities/sciencefair/post/2010/09/volcanoes-neanderthals-extinct/1 

Volcanoes wiped out the Neanderthals some 40,000 years ago, suggest archeologists, setting the stage for modern humans in Europe.

Stumpy but strong, the Neanderthals disappear from the European fossil record by about 30,000 years ago, replaced about that time by modern-looking humans. In the upcoming October Current Anthropology journal, researchers led by Liubov Golovanova of Russia's ANO Laboratory of Prehistory in St. Petersburg report that volcanic dust deposits in a cave in the Caucasus point to an ecological catastrophe wiping out our Neanderthal cousins, not warfare or competition for food.

According to the study, ash, pollen and tools left in Mezmaiskaya Cave suggests that "volcanic eruptions had an unusually sudden and devastating effect on the ecology and forced the fast and extreme climate deterioration ('volcanic winter') of the Northern Hemisphere." They point to evidence for a massive eruption around 40,000 years in southern Italy as well as a smaller eruption a bit earlier in the Caucasus.

"On the basis of these data, we offer the hypothesis that the Neanderthal demise occurred abruptly (on a geological timescale) at around 40,000 BP (before present) after the most powerful volcanic activity in western Eurasia during the period of Neanderthal evolutionary history. We further hypothesize that this catastrophe not only drastically destroyed the ecological niches of Neanderthal populations but also caused their mass physical depopulation in most of their habitation areas across Europe and the Near East. This loss of viable source populations may have significantly contributed to the eventual extinction of Neanderthals throughout their range," says the study.

Neanderthals in the cave and elsewhere in Europe were famously dependent on large game, such as bison and reindeer, the authors note, making them vulnerable to famine in those grazing species.

In commentaries accompanying the paper, however, experts disagreed on the study's conclusions:

"There are no compelling archaeological proxies for Neanderthal presence in Europe after ∼38,000 BP and none for modern human presence before the same time. It therefore seems plausible that in most regions Neanderthal extinction—or at least significant depopulation—preceded the arrival of Homo sapiens," says archeologist P. B. Pettitt of the United Kingdom's University of Sheffield. "The second volcanic eruption recorded in the cave's sediments seems to have been critical to Neanderthal extinction— or at least disappearance—in the region."

But F.G. Fedele of Italy's University of Naples, who led the work pointing to the ancient Italian eruptions calls the study, "shaky," criticizing their ash layer results.

The authors display, "disproportion between facts and ambition, they loudly voice a theory of the role of volcanism in the Transition. Having upgraded our volcanic winter to a nuclear winter, the authors reveal that there was extermination, a 'mass death of animals and hominins'—are hominins not animals?—providing a convenient vacuum for an incoming species," Fedele says. "This facile, pre-Darwinian catastrophism shuns the challenge of exploring displacement instead of replacement, ecosystemic stress, selection for innovation—a whole gamut of possibilities."

In a reply, Golovanova and colleagues maintain that the "volcanic winter" scenario "provides a link between this exceptional volcanic catastrophe and the unusually sudden and large-scale ecological crisis that preceded the fast demise of Neanderthals." They argue the ash dating in their paper supports their results, although they acknowledge the complaints by Fedele and others. "Clearly, we disagree about the significance of this important event on Neanderthal populations. "