I once read an article that proposed the idea that the reason why we see crooked teeth in modern humans and not in ancient humans is because of our diets, especially when we are very young.
Modern human babies eat soft foods. Because of that their jaws don’t develop as robustly as if they had eaten harder foods. Because of this, their jaws don’t get large enough for all the teeth to fit in place in their proper orientation. In contrast, aboriginal people in Southeast Asia have straight teeth. The authors argued that this is because their babies eat many of the same hard foods the adults eat. So their jaws develop as they should and there’s room for all their teeth to fit.
I don’t know how valid this is. It sorta dovetails with the video in that crooked teeth correlate with smaller jaw size.
I’m not sure I buy any of it. I sent some spit to 23 and Me last month and found out I have more Neanderthal DNA than 66% of their clients. If I have all that troglodyte DNA, then why did I need braces when I was a kid? I’d like to see your precious James Nestor answer that!