Why are our teeth so bad? Why do we get tooth decay and crooked teeth? It may have something to do with what we eat, not just today – but 10,000 years ago!
Unlike most animals, humans have undergone a rapid dietary change in a relatively short period of time.
As an oversimplification, take any animal species, and you’re looking at a creature that’s been eating the same general diet for the last million years or so.
Now, look at humans. Our diets have changed drastically in the past 20,000 years which in evolutionary terms is extremely fast. We’ve gone from diets heavy in fibrous plant materials, which are tough and require a lot of chewing, to being able to eat an entire meal through a straw!
Our early ancestors ate a lot of tough hard foods, and this required large jaws with teeth that could break down this material. The more the teeth can break down the food, the more energy can be potentially extracted from it by the body.
As our diets have gotten softer, our ancestors could get away with smaller jaws – which required less energy to grow and use. Using less energy to eat while acquiring the same energy in your diet as your large-jawed brethren = evolutionary advantage.
So humans have evolved much smaller jaws in a very short order of time. Having smaller jaws and the same number of teeth means that there is far less space, causing all manner of problems (think: wisdom teeth, cross-bites, malocclusion etc.). Add to that the modern diet full of sugar, and you’ve got the perfect scenario for bad teeth!