Chew on this: Humans have more efficient jaws than many of our nearest relatives. Using digital 3D skull models, researchers compared the jaw muscles of humans to our close relatives, including living species such as chimpanzees, gorillas, orangutans, and extinct ones like Paranthropus boisei (sometimes called "Nutcracker Man "). When flexing the simulated munching muscles, the human's bite force was at least 42% higher than most other the primates. Out of all the modeled skulls, the human cranium also experienced the second least amount of stress during a chomp (blue areas in image indicate the least stress and white areas indicate the most), suggesting that humans can produce greater mastication forces with less impact than most of the other species in this lineup (the white-handed gibbon was the most efficient). The results, published  online tomorrow in the Proceedings of the Royal Society B, challenge earlier notions that our large brains came at the cost of a less powerful bite and increases the number of hard and tough foods that ancient man might have chowed down on.
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