Researchers in Russia believe that climate change triggered by early massive volcanic eruptions drove the Neanderthals to extinction and cleared the way for modern humans to thrive in Europe and Asia. Their theory is based on the findings of recent excavations in a cave in southern Russia, revealing layers of volcanic ash that coincide with large-scale volcanic events that occurred around 40,000 years ago .Their research is published in the October issue of the journal Current Anthropology. The research was led by Liubov Vitaliena Golovanova and Vladimir Borisovich Doronichev from the ANO Laboratory of Prehistory in St Petersburg in Russia, who analysed the two layers of volcanic ash found in the Mezmaiskaya cave in the Caucasus Mountains, a site rich in Neanderthal bones and artefacts. '[W]e offer the hypothesis that the Neanderthal demise occurred abruptly (on a geological time-scale) ... after the most powerful volcanic activity in western Eurasia during the period of Neanderthal evolutionary history,' the researchers said. '[T]his catastrophe not only drastically destroyed the ecological niches of Neanderthal populations but also caused their mass physical depopulation.' They claimed that geological layers containing the ashes held evidence of abrupt and potentially devastating climate change, while sediment samples from the two layers revealed greatly reduced pollen concentrations compared to surrounding layers. The researchers said this was an indication of a dramatic shift to a cooler and dryer climate, adding that they found no traces of Neanderthal life at Mezmaiskaya after the eruptions. The ash layers correspond chronologically to what is known as the Campanian Ignimbrite super-eruption that occurred around 40,000 years ago in modern-day Italy, and a smaller eruption is thought to have occurred around the same time in the Caucasus Mountains. The researchers argued that these eruptions caused a 'volcanic winter' as ash clouds obscured the Sun's rays, possibly for years. The climatic shift devastated the region's ecosystems, 'possibly resulting in the mass death of hominins and prey animals and the severe alteration of foraging zones'. Questions over the disappearance of the Neanderthals and the apparent concurrent rise of modern humans left many anthropologists wondering what happened. Many theories have been put forward over the years, including the suggestion that their low population density may have made them vulnerable, that their lack of technological know-how may have left them unable to cope with the ice age, or they may have had too narrow a diet that made them less adaptable than other species to change. Modern humans have been implicated in the demise of the Neanderthals, with some even being blamed for stoning the Neanderthals to death. However, this latest research suggests that the Neanderthal may have merely been in the wrong place at the wrong time. 'Early moderns initially occupied the more southern parts of western Eurasia and Africa and thus avoided much of the direct impact of the ... eruptions,' said the researchers. And while advances in hunting techniques and social structure clearly aided the survival of modern humans as they moved north, they 'may have further benefited from the Neanderthal population vacuum in Europe, allowing wider colonisation and the establishment of strong source populations in northern Eurasia'. Nonetheless, the researchers stressed that this study was far from the end of the road and clarified that more data from other areas in Eurasia is needed to fully test the volcanic hypothesis. The Mezmaiskaya cave offers 'important supporting evidence' for the idea of a volcanic extinction, they concluded.