Neanderthals had big noses and long faces because they led extremely active lives and needed to get lots of oxygen into their lungs fast, computer modelling reveals.
In a paper published in the journal Proceedings of the Royal Society B, researchers led by Stephen Wroe from the University of New England in Australia reveal the first full reconstruction of Neanderthal skulls, using 3D modelling and computer-based engineering.
The results provide convincing explanations for Neanderthals’ characteristic facial features, which some commentators in the past have interpreted as brutish signs of brawny dullards. The reality, say Wroe and his team, is startlingly different.
“Our conclusion was that the distinctive, projecting Neanderthal face is an adaptation linked with an extreme, high energy lifestyle,” he says.
“It may be because Neanderthals were routinely involved in very strenuous activities, such as running down and killing large animals, or it may simply be that they needed to burn a lot of oxygen just to stay warm in their Ice Age habitats. Or it could be some combination of both.”
To make their findings, the team constructed intricate 3-D computer-based models of three Neanderthal skulls, including delicate structures such as those inside the nasal cavities. The researchers compared the results to skull models derived from a modern human and from a likely direct human ancestor, Homo heidelbergensis.
In so doing they were able to discount one enduring theory advanced to explain Neanderthal skull shape – that it was adapted to facilitate strong bite force.
“In fact, at least some modern humans are arguably better suited to this role,” Wroe says, “using less muscle force to achieve the same bite force, while developing less strain in the bone.”
The real advantage of the big nose and elongated face became clear once the scientists applied a couple of analytical techniques known as finite-element analysis and computational fluid dynamics.
This revealed that Neanderthals were far better than either modern humans or H. heidelbergensis at getting air into their lungs via their noses. The ability to breathe deeply and fast, Wroe says, indicates that they lived high-energy extreme lives.
The researchers also acknowledge that Neanderthal facial structures would have allowed them to humidify and warm the air they breathed in, which would have helped them survive life in cold climates. They were better at doing this than H. heidelbergensis, the paper notes, but modern humans, with smaller noses and shorter faces, can do it even more efficiently.
“Neanderthals looked very different to us,” Wroe says. “They were shorter, far more robust and muscular than your average modern human, and, perhaps most obviously, they had huge noses and long mid-faces.
“This projecting mid-face is a true Neanderthal novelty, a specialisation which sets them apart, not just from us, but from their ancestors too.”