Among anthropologists, a little ash has reignited a hot debate: What happened to Neanderthals? Excavators studying a Russian cave filled with Neanderthal bones-the skulls sometimes identified by a large braincase and thick brow ridges-found layers of volcanic ash in the sediment and concluded that a series of major eruptions in Europe 40,000 years ago were responsible for wiping out the ill-fated hominins.
It happened not by lava flow or asphyxiation, they say, but by a giant ash cloud that blocked sunlight for years, reducing vegetation and consequently thinning the animals that served Neanderthals' presumably stone tables. But skeptics of this volcano hypothesis insist it was modern man who drove Neanderthals into oblivion, either by overcrowding or bloodier methods as Homo sapiens populated swaths of Europe.
Among the stone tools, ornaments, and several hundred Neanderthal fossils that anthropologists have uncovered, there's one thing they haven't found yet: agreement. Theories abound, attempting to explain who the Neanderthals were and how they disappeared.
Two prominent ones: In 2004, 30 scientists wrote that Neanderthals died out gradually because they failed to adapt to climate change (global cooling, which would have reduced hunting options). In 2007, a study in Nature determined that global cooling would have been too slow or too mild to cause total extinction. The two views are typical of the lack of consensus surrounding Neanderthals.
Many anthropologists say something else happened to the furrow-browed race: They simply interbred with and were absorbed into modern humans. Compare these peer-reviewed conclusions, listed by publication date:
August 2007: A skull from Romania displays both Neanderthal and modern human characteristics, showing the two groups interbred.
August 2008: A study of mitochondrial DNA concludes the two groups did not interbreed-their last common ancestor lived between 520,000 and 800,000 years ago.
May 2010: A new DNA study finds all modern ethnic groups except for Africans have 1 percent to 4 percent Neanderthal DNA. So the two groups must have interbred about 60,000 years ago, before modern humans spread out to populate the earth.
Notice the disparate results? They're just a handful of many unresolved Neanderthal claims. Since there's no consensus anyway, maybe alternate perspectives are in order: Neanderthal scholar Jack Cuozzo, who made advanced X-ray measurements of principal Neanderthal skulls beginning in 1979, thinks Neanderthals were fully human, and he wrote about his firsthand study of their fossils in his 1998 book Buried Alive.
Cuozzo, who was criticized by some of his colleagues for taking the Bible literally, believes Neanderthals were the men described in Genesis (post-Babel) who lived to be exceptionally old. They were bony because their heads and features continued to grow throughout their lives. They matured more slowly as well. As you might expect by now, not everyone agrees, even among creationists. But the approach is refreshingly unconventional in a discipline crowded with convention.