Eating meat has made us who we are today: evolved, intelligent humans, able to use a verbal language. A new research suggests that not eating only fruits and vegetables but also food rich in animal proteins allowed humans to evolve, transforming both the anatomical and the intellectual levels.
We often take chewing for granted, but not Daniel Lieberman, professor in the department of human evolutionary biology at Harvard University and co-author of the study. "Every time I go out to dinner, I watch people chew" Lieberman told to NPR. "And sometimes, I actually count how many times they chew".
About three million years ago, living on fruit and vegetable alone was not a big deal for our ancestors: there was a great abundance of this kind of food, but the contribution of calories was not very satisfactory. Eating potatoes, beets, carrots or roots with a higher nutritional value was also possible, but much more difficult to chew. Our ancestors spent a lot of time chewing, about 50% of their day was spent chomping, just to get enough calories and, according to Daniel Lieberman, their faces show it. "Our ancestors had big faces, huge chewing muscles, much larger teeth".
Everything changed when they started eating meat, in particular raw meat, because they didn't know how to cook it yet. But they have figured out how to break sharp edges of stones in order to cut the meat. These stone blades are the precursor of modern knives. Therefore chewing changed thanks to the advent of these tools.
Researches asked some volunteers to chew pieces of raw goat and they were able to calculate that cutting meat reduces the number of chews we take by 2.5 million chews per year, which is a very big difference. This technology had such a massive effect on our evolution and on the way we chew our food. This resulted in smaller teeth and smaller jaws. According to Daniel Lieberman, that's when the bones of the neck and skull have changed, encouraging the development of a larger brain and a more advanced dialectical skills.
This study has been used as proof against ideological veganism. According to them a meat-based diet as always been bad for humans, but this paper suggests that in order to get a bigger brain we need more than vegetables. Not only processing and eating meat came instinctively to us, it’s also quite possible that without a diet that included generous amounts of animal protein, we wouldn’t even have become human, or at least not the modern, verbal, intelligent humans we are today.