Lifestyle is known to affect many aspects of health but now a UK anthropologist says it could even change the shape of our jaws.
Dr Noreen von Cramon-Taubadel of the University of Kent reports her findings in this week’s edition of the Proceedings of the National Academy of Sciences.
She made detailed measurements of the skulls and jaw-bones (mandibles) of nearly 300 individuals from 11 different subsistence cultures – some from hunter-gatherer societies and some from societies with primitive agriculture.
The measurements were of skulls in museum collections, which were from people who lived in the past couple of thousand years.
“These people are likely to be analogous to people living today,” says Cramon-Taubadel.
She found that people from hunter-gatherer societies had narrow, long mandibles, whilst people living an agricultural life tended to have short, broad jaw-bones.
Cramon-Taubadel then looked for correlations between the shape of their jaw-bones with other factors such as climate, geography, genetic make-up and type of lifestyle and found the difference was not genetic.
“The pattern was consistent, regardless of which part of the world the people came from,” says Cramon-Taubadel. “The results indicate that there is something biomechanical, rather than something genetic, that is altering the way the mandible grows.”
“Presumably the children growing up in these different situations have different chewing behaviour,” she says. Rather than happening over an evolutionary time-scale, the change to the mandible that she is talking about happens on an individual level as each child is growing up.
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