How much information can scientists really glean from just the back of the skull, and just the left half at that? Actually, quite a lot, Harvati says: That region is very informative when telling different hominins apart. Apidima 1 lacks several traits that are distinctively Neanderthal, while its rounded shape “is considered to be a uniquely modern human feature that evolved relatively late,” Harvati says.
But “it doesn’t look like classic Homo sapiens,” says Wragg Sykes, who wonders whether it represents a group of humans that had been interbreeding with Neanderthals or other ancient hominins. “Obviously everyone is going to want to see DNA out of that skull,” she adds.
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The team’s analysis “is convincing,” and its study is one of several that have recently shaken our understanding of human evolution, says Mina Weinstein-Evron from the University of Haifa. Finds like 300,000-year-old bones from Jebel Irhoud in Morocco suggest that our species arose from several diverse populations that lived across Africa. Meanwhile, bones from Misliya and Apidima tell us that early humans then expanded into other continents, and interacted with other hominins, far earlier than previously thought.
The Apidima skulls also suggest that the accepted story of Europe, in which modern humans eventually replaced the long-dominant Neanderthals, is too simple. Instead, Harvati thinks that modern humans were already in Greece about 200,000 years ago; they were then replaced by Neanderthals, who were themselves replaced by humans about 40,000 years ago. A similar cycle of competition, where Neanderthals and humans repeatedly replaced each other, seems to have happened in the Levant, the Middle Eastern region that includes Israel and Syria. “We can’t refer to Homo sapiens as a ‘success’ in terms of being able to move into new areas and stay there,” Wragg Sykes says.
Of course, it’s possible that both hominins just lived together. But genetic studies suggest that while they did intermittently meet and mate, the groups weren’t in constant contact. “I don’t think they coexisted,” says Harvati. “But maybe I’m wrong. We don’t have the evidence one way or the other, and we need to look for more.”
Greece is a good place to start. “It’s at the crossroads of three major continents, and it’s a refuge where animals and humans could survive at the height of the ice ages,” Harvati says. “You’d predict population dispersals and range contractions in these areas, the possibility for contact [between different groups], and a more diverse human-fossil record than you’d find in distant parts of Europe. There aren’t many fossils in the region, but it hasn’t been much of a research priority.”
The Apidima skulls “illustrate that there is much to learn in areas outside of western Europe and the Levant, where most of our research has concentrated,” says Bailey. “We may find the first anatomically modern humans lacked the kind of advantages that later Homo sapiens may have had”—the very same advantages, she says, that led to our “ultimate domination.”