The move from chasing down our food to growing our own grub left an indelible mark on our biology. One change resulting from the switch to softer foods was we didn't need to spend so much energy chewing. Studying hundreds of pre-industrial era human skulls, new research has singled out the foodstuff with the biggest impact on our skull shape: cheese.

The idea that settling down and eating softer foods changed our skulls isn't entirely new: a study published in 2011 blamed our agricultural shift for a range of dental issues that plague us today, including tooth crowding and overbites.

But to determine just how far-reaching those farming-induced changes might have been, researchers from UC Davis have taken a wider snapshot of the transition. The team studied skulls from 25 different groups around the world, including 559 crania (the main upper section of the skull) and 534 lower jaws, and modeled how their diet might have changed the shape and size of the bones in that time.

Backing up previous research, the team found some changes in the skull shapes of early humans who were farming and eating cereals, dairy, or both. Dairy specifically was the largest driver, with populations eating a diet including that showing the most drastic changes in skull morphology. It seems that once we invented soft foods like cheese, our jaws didn't need to be quite as big and powerful.

"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," says David Katz, an author of the study. "At least in early farmers, milk did not make for bigger, stronger skull bones."

That said, the cheesy changes were fairly modest, in the grand scheme of things. While they had a noticeable impact, other factors like location and sex were bigger drivers of the evolution of our skulls.

The research was published in the Proceedings of the National Academy of Sciences.

Source: UC Davis