The article says that jaws got smaller due to agriculture making food softer, and this evolutionary change causes both snoring and crooked teeth, which in turn braces are a bandaid for. The point made in the heading isn't really discussed except in a parenthetical ("braces may also make this worse"). Baity headline.
what was really surprising was that they made the connection that modern day hunter gathers do not have the teeth problems we have, but then jumped to stating our jaws evolved smaller faces/jaws.
Evidence does not seem to coincide with that hypothesis, and even their statements are contradictory. There is growing evidence that because we eat soft food as children now, our jaws do not grow to their evolutionary designed size.
Indeed. "Evolution" would imply that humans with bigger jaws were somehow disadvantaged and died before they could pass on their genes. Really bad article.
I don't have an opinion on whether the subject is a case of gene selection or gene expression, but your binary caricature of evolution is misleading. A trait can be weened from the gene pool simply because it costs energy without providing a benefit, causing those with that trait to underperform compared to those without it. Even if individuals are living and passing on their genes, a trait might fade from the gene pool over time because competitors are able to claim a bigger proportion of resources, reproducing quicker and more often.
The human appendix is like that: it isn't directly harmful, but it's shrunk simply because it's a waste of energy.
The point is the trait hasn’t been lost at all. If people with this problem had a kid and fed them hard foods from the get go then, supposedly, they would grow the larger jaw and not have the problem with cramped teeth.
