We coevolved with tools long before we began to cook our food. Interesting!
One of the biggest puzzles in human evolution is how species such as Homo erectus evolved smaller teeth, smaller faces, and smaller guts, and yet managed to get more energy from food to pay for their bigger brains and bodies before cooking was invented.
... our ancestors between 2 and 3 million years ago started to spend far less time and effort chewing by adding meat to their diet and by using stone tools to process their food. ... and made possible further changes that helped make us human.
"Eating meat and using stone tools to process food apparently made possible key reductions in the jaws, teeth and chewing muscles that occurred during human evolution,"...
...by processing food, especially meat, before eating it, humans not only decrease the effort needed to chew it, but also chew it much more effectively"
"What we found was that humans cannot eat raw meat effectively with their low-crested teeth. When you give people raw goat, they chew and chew and chew, and most of the goat is still one big clump - it's like chewing gum," ... "But once you start processing it mechanically, even just slicing it, the effects on chewing performance are dramatic."