Farming and dairy responsible for change in the human skull

Have you ever wondered why the human head and jaw is so slender? According to a recent anthropological study, when humans moved from hunting and gathering to farming, the distinct difference in chewing requirements changed the shape of the human skull.      

Hunters and gatherers ate food that they needed to chew and gnaw on. This needed significant effort. However, as humans started farming, they made the transition to a much softer diet. Added to this, the discovery of dairy products also reduced the effort put in chewing. David Katz along with Professor Tim Weaver and statistician Mark Grote from Department of Anthropology, University of California, studied the influence of the diet on the shape and size of the human skull and noted differences in the skulls of groups that ate only cereals or dairy or both cereals and dairy. The findings of this research were published in the Proceedings of the National Academy of Sciences.

A collection of 559 crania and 534 lower jaw bones from more than two dozen pre-industrial populations were used in the study. "The main differences between forager and farmer skulls are where we would expect to find them, and change in ways we might expect them to, if chewing demands decreased in farming groups," said Katz. The biggest changes were in the group consuming dairy. Since soft food such as cheese did not need much chewing, the shape of the jaw and consequently the shape of the skull had become slender as well as less powerful.

DOI: 10.1073/pnas.1702586114