Before humans learned how to grow their own food and cook it over a fire, they hunted and gatherer and were forced to chew a lot more tough, fibrous foods. The "softening" of the diet associated with the progress took place tens of thousands of years ago and could not but affect the anatomical structure of the teeth, jaws and skull as a whole. This issue is discussed in an article published in the journal Proceedings of the National Academy of Sciences.
The authors of the article, David Katz and colleagues at the University of California, Davis, used open data to measure 559 skulls and 534 mandibles from representatives of 25 different historical communities of the pre-industrial era - from North America to southern Africa, the Far East and Australia. … For each, the diet was determined, taking into account the popularity of dairy products, rice and other soft "domesticated" grains in it. Indeed, some differences were found in people who regularly consumed them.
The changes affected the forehead line, led to a slight decrease in the lower jaw. The most noticeable changes were in populations that ate heavily dairy products, including cheese - of course, these bland foods required far less effort and chewing ability than raw roots and hunter-gatherer fruits.
“The main differences between the skulls of gatherers and peasants were exactly where we expected to find them, and were exactly those that should be associated with a decrease in the need for chewing,” says David Katz. However, scientists emphasize that these changes, which have occurred over the past tens of thousands of years, are not too serious, and remain small in comparison with the difference between the skulls of men and women, or simply representatives of different populations, even eating exactly the same.