ZURICH, SWITZERLAND—According to a report in Science, the spread of agriculture and consumption of easier-to-chew foods may have led to changes in human jaws and their arrangement of teeth, which in turn allowed people to make new sounds and create new words. In the 1980s, linguist Charles Hockett suggested that chewing tough, gritty food would have put force on hunter-gatherers’ lower jaws, making the bone grow larger so that the upper and lower teeth aligned in an “edge-to-edge” bite. Such a bite would have made it hard to push the upper jaw forward to make the sounds “f” and “v,” Hockett reasoned. Linguist Balthasar Bickel of the University of Zurich and his colleagues used computer models to test this idea and compare how such sounds, known as labiodentals, are made with an edge-to-edge bite and with the overbites that developed in people who lived in agricultural societies. Bickel suspects “f” and “v” sounds were first made accidentally by wealthy people who ate soft foods. The researchers also examined hunter-gatherer languages, and found that hunter-gatherers use about one-fourth of the labiodentals that farming societies do. Bickel’s colleague Steven Moran pointed out that, with the ability to make new sounds came new problems. “Our lower jaws are shorter,” he said, “we have impacted wisdom teeth, more crowding—and cavities.” To read about an archaeological mystery involving teeth, go to “The Case of the Missing Incisors.”