Recent humans whose communities subsisted by farming, a relatively recent pursuit, tended to have shorter mandibles — lower jawbones — than hunter-gatherers.

Noreen von Cramon-Taubadel at the University of Kent in Canterbury, UK, compared hundreds of jaw and skull measurements from 11 populations around the world that practised varying degrees of hunting, fishing, foraging and farming. No matter what their home or their ancestry, the hunter-gatherers had longer, narrower mandibles than humans who subsisted on crops, dairy or farm animals.

Agriculture and animal farming began emerging around 10,000 years ago in various regions of the world. As populations turned to farming, a diet of softer, more processed foods may have spurred the evolution of daintier jaws.

Proc. Natl Acad. Sci. USA http://dx.doi.org/10.1073/pnas.1113050108 (2011)