Why Don't We Need Our Wisdom Teeth Anymore?

There was a time when humans needed those extra molars, but that all changed and now they just take up space. What happened?

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First things first. Humans usually have 32 teeth: 8 incisors, 4 canines, 8 premolars, 8 molars, and 4 third molars. Those third molars are also called wisdom teeth. Some people have them, but many people don't. Research says that as many as 65 percent of people today never develop wisdom teeth at all. Many may develop one, two, or three, but not a full set. Why is this? Wisdom teeth are largely outdated, thanks to the course of human evolution. It's estimated that some 100 million years ago, our ancestors' jaws had enough room for all 32 teeth. This was important because a diet of raw meat and greens relied on more teeth to break everything down. Overtime, human ancestors developed cooking methods that helped the digestive process. Having a third set of molars was no longer necessary. Research from the University of Tennessee at Knoxville has found that third molar agenesis tends to be common in African Americans and Inuits. That is, in these communities, there are higher rates of not having even the follicles that produce wisdom teeth. So when did we start losing wisdom teeth? It's hard to say, but Princeton anthropologist Alan Mann found the oldest jaw fossils in Asia that date back to 300 to 400,000 years ago.

Read More:
Are people without wisdom teeth more highly evolved? (How Stuff Works)
"There was a time when our jaws could comfortably accommodate all 32 teeth, including the third molars. You have to go back about 100 million years ago, though, to the prehistoric version of man."

The changing wisdom on wisdom teeth (USA Today)
"Some healthy wisdom teeth may be OK to keep, as long as you look out for signs of trouble."