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.
