> It is abnormal for humans to need glasses. It's also abnormal for humans to need braces and to need their wisdom teeth surgically removed.

It's not. Just because there wasn't a documented cases of weakly sighted people doesn't mean that they didn't exist. Or do you seriously believe all prehistoric humans had 20/20 eyesight?

And unless your teeth are crooked line vines you probably don't need braces from medical standpoint. Unless it causes issues to your jaw. Same with wisdom teeth.

> The list of maladies caused by modern diet and lifestyle is infinite and unknowable.

What exactly in modern diet and lifestyle causes issues that you've listed?

Soft foods cause crooked teeth. Ancestral humans ate raw tubers and other very chewy things that exercised their jaws, and the growing human body needs this resistance/exercise. If you look at modern hunter-gatherer tribes with traditional diets, they have a far lower rate of crooked teeth we'd solve with braces than the developed world.

Sterile environments/too-low pathogenic load causes allergies. The immune system expects a base-rate of infection; if it doesn't see that, it upregulates. Allergies are a first-world disease; they're far less prevalent in less developed countries, and you even see the effect in immigrants- their allergy rates go up after a few years of living in a developed country.

> Or do you seriously believe all prehistoric humans had 20/20 eyesight?

The prehistoric realities were harsh and nearsighted individuals had little chances of survival and procreation (natural selection). In the modern society perfect eye-sight is not as important for survival as in the prehistoric society, thus more tolerance to its greater variability.

Sunlight exposure has been shown to be protective of eyesight, and we spend more time indoors focusing on screens.

The timespan is too short for evolution to have had a considerable impact.

> The timespan is too short for evolution to have had a considerable impact.

I am not talking about evolution as in developing new species but about survivability of naturally occurring variations. Modern humanity timespan is not enough in developing new genetic traits but long enough to alter effects of natural selection. BTW, due to advances in medicine nowadays we have children born and survive into adulthood with medical conditions that were terminal just 100 years ago. Survival variability (in developed world) is much broader that it was in recent historic past (e.g. middle-ages). This is a plain fact.

But the timeline is too short even for that. The number of children who survive today, despite genetic issues, who would not have survived 100 years ago, is miniscule compared to the extent of nearsightedness today.

Wisdom teeth used to just be a problem that either killed you, or you lived with lots of pain from, or you paid a guy to try and do something about them.

I don't know why people are so big on "we used to not need X in the distant past" tropes: yes we did, but we also just let lots of people die from it, or live a life of agony or being shunned as ugly/unclean/unable.

Crooked teeth really didn't exist in the farther out past. If you look at the jawbones of Neolithic people, they all have perfectly aligned teeth.

The theory is that we're not chewing hard enough food, which leads to insufficient jawbone growth as a kid, leading to not enough space for your teeth.

I guess I should thank my mom and her well-done steaks for my decent jaw and relative lack of dental issues.

If they killed that many people, how did they escape natural selection?

If it happens after the person has a chance to raise offspring to a sufficient survival age, then it would not adversely affect natural selection.

They didn’t kill you. You needed them, after your second teeth - what we call your ‘adult teeth’ - had rotten and fallen out.

Killed<>eradicated.

Only Americans are afraid of wisdom teeth. 90 percent of the rest of the world keep them with no problems whatsoever.

(Something something medical cartel...)

Where you got that from? They are surgically removed outside of USA regularly when they grow bad and cause infections.

> when they grow bad

Yes, exactly. Which actually happens not so often and usually around the time the rest of your teeth go bad and you start to need surgery anyways.

I think the difference is the US is very likely to remove them preemptively.