Did you know that people of Native American descent are quite likely to have grooves on the back of their front teeth? This is something that has been noted by dentists for at least 100 years, but it is undoubtedly a feature that goes way back and did not suddenly manifest itself a century or so ago.
Another odd thing is that the same feature has been noted in people in Siberia, which adds strength to the generally held belief that America’s first inhabitants migrated from North Asia by crossing the land bridge that once existed where the Bering Straits are now. This would have been during the last Ice Age.
The big question, however, is why such a feature should have evolved in the first place? What possible advantage could there be in having grooves at the back of your front teeth? Maybe some Native American (or Siberian) out there can enlighten us!