The one I was thinking of is the (hypothesized) reduction in jaw size due to less need for powerful chewing, while teeth stayed the same size leading to many problems
Yeah. I remember a story about an anthropologist who went to a indigenous tribe, IIRC somewhere around the pacific, he took photos of everyone’s teeth. Everyone had straight teeth from the kids to the elderly. Then a generation later someone else did the same thing. Went to that tribe and took photos. Many kids had crooked teeth. The only thing that changed is that they adopted a Western diet.
Can’t remember the name of that anthropologist, though.
You get cavities from sugar not crooked teeth. It’s that our food has become softer over the last few thousand years. Our jaws don’t get enough exercise during their developmental years. So they don’t grow large enough for our teeth. It’s also why many people have impacting wisdom teeth.