History Stories


Scientists have long theorized that the shift from a hunter-gatherer existence to agriculture—and, more specifically, the dietary changes that came with it—affected the development of the human skull and lower jaw. Groups practicing both lifestyles still exist in today’s world, so experts don’t have to rely on fossils to investigate the matter. But until recently, only localized studies had provided support for the hypothesis.



What accounts for the difference? Cramon-Taubadel’s study highlights the possibility that hunter-gatherers give their lower jaws a workout—and encourage their growth—by chewing tough, unprocessed foods. People who rely on agriculture, meanwhile, tend to eat softer, cooked items that require less forceful gnawing, resulting in underdeveloped jawbones.

“Chewing behavior appears to cause the lower jaw to develop differently in hunter-gatherer versus farming populations, and this holds true at a global level,” said Cramon-Taubadel. “What is interesting is that the rest of the skull is not affected in the same way and seems to more closely match our genetic history.”

This explanation remains speculative, so those with dental problems shouldn’t switch over to a raw diet just yet. Cramon-Taubadel’s paper appeared November 21 in the Proceedings of the National Academy of Sciences.
