Science

How cheese changed the shape of the human skull

How cheese changed the shape o...
As we switched from hunting to farming, soft foods like cheese changed the shape of the human skull
As we switched from hunting to farming, soft foods like cheese changed the shape of the human skull
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The researchers measured specific points on human skulls, and found differences between the skulls of foragers and those of farmers
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The researchers measured specific points on human skulls, and found differences between the skulls of foragers and those of farmers
As we switched from hunting to farming, soft foods like cheese changed the shape of the human skull
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As we switched from hunting to farming, soft foods like cheese changed the shape of the human skull

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

14 comments
Nygaard
Survival of the fittest, natural selection how is that occurring here?
From what I understand this article is saying, when we started eating cheese and other softer foods our jaws and bones in the head didn't need to be as strong.
So how is natural selection at play here. How does having a less strong jaw allow for more success in passing on DNA when compared to those with stronger jaws? From everything I've read and been taught the mutation of DNA or the trait needs to be advantageous to the species so as to provide a marked advantage when it comes to passing on of the DNA. So how does a less strong Jaw help in that way?
Also wouldn't the increase in calcium from the cheese work against the weaker less strong bones?
MQ
Lemarckian evolution at its finest. (I need therefore I change)
?? For a particular "mutation" to become a universal trait we need to see either parallel equivalent mutations in different populations or a common ancestor.
On the other hand the potential could be hard-coded into the DNA allowing change to occur as a response to stimulus (eating cheese/pie) without any mutation required.
David
The human skull changed shape long before cheese was invented.
Ralf Biernacki
@Nygaard: Evolution cuts corners whenever it can get away with it. Whatever is currently unneeded gets trimmed away, because it saves material and energy. Jawbone and teeth are expensive to make, and energy and calcium saved growing them can be used elsewhere: most likely growing a slightly taller body, thus improving sexual selection chances.

This is economizing with a vengeance, and sometimes it doesn't makes sense from a more far-reaching point of view---but the weakness of natural selection is that it has zero foresight. It works just like corporate decision making: a slight economic advantage here-and-now, at the cost of a huge prospective disadvantage, wins the evolutionary race every time. That's how we lost the capacity to make vitamin C---at some point, when the ancestral monkey was a fruit-eater, there was a slight energetic advantage to no longer retaining the pathway. Future generations received a major handicap, but the future is invisible to the natural selection process. There are countless examples like this: the pathetic thermal inflexibility of most marine species, diabetes (which confers a very slight advantage in times of famine). . . Apparently even a minuscule energetic saving is a very powerful evolutionary selection factor.

Rustgecko
Most human's cannot process the milk protein lactose after early childhood. Does this mean this change effected caucasians and certain East African tribes only?
Nygaard
@Freederick I'm sorry but your response is complete opinion and can not be proven in a scientific way, it's opinion. Please provide a scientific meathod by which your claim can be proven. To say volition will find a way, which is pretty much what you've said is just something evolutionists say when they are stumped.
@MD So,you are saying you don't know.
Thanks for the responses and I don't mean my remarks to be anything other than respectful exchange of ideas and I pray they are taken as such.
ljaques
Yes, the Brie Human was a definitive step down for the physicality and step sideways in the mentality of humankind. It introduced a new way of thinking in modern man, which in turn led to synchronized swimming and rhythmic gymnastics (ribbon tied to stick) being tagged as Olympic sports 'disciplines'.
Douglas Bennett Rogers
There are still people who can bite through chains. Maybe they are even a modern evolutionary branch. This is clearly genetic, as with many other strength attributes. Most people can't train to a 400 lb. bench press. A fairly large minority will get there easily.
Carl23
@Nygaard, your original question was the right one to ask, as the effect on natural selection is ultimately what matters. However, while not a biologist or paleobiologist, I have to say that Freederick makes a lot of sense. While the effect might be small, over millions of years the tiniest changes can have a significant impact. It is also possible that, for breeding purposes, there is something inherently more appealing about a male jaw that looks less like a hyena's. I don't have any specific examples to back that up, or Freederick's assertion, but would be interested if there is anyone knowledgeable in the field who has an informed opinion.
physics314
It's always interesting to learn things like this about humans, mainly because our long lifespan makes evolutionary changes harder to spot than in shorter-lived species. It truly is incredible how quickly (on a historic scale) traits become prevailing, even in humans, given a change of circumstance - such as the introduction of dairy into the diet.