19
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Why prehistoric humans needed no braces: Crooked teeth are a modern phenomenon and a telltale sign of an underlying epidemic
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- Title
- Why Cavemen Needed No Braces
- Word count
- 1487 words
There's also this much longer article by scientific American in this issue.
This article basically argues that teeth and jaws evolved for a hunter-gatherer diet and our modern diet means either the jaws are underdeveloped or the teeth grow too large (or both) and so our teeth problems are modern (as in since the industrial revolution). The aspect of the article I found interesting is the implication that big, traditionally masculine jaws are desirable for evolutionary reasons rather than cosmetic ones, for reasons that pertain to both sexes.
Isn't that the case with other traits that's desirable? Like wide hips in women for better births etc. I don't know but it seem like every desirable trait always end up being evolutionary somehow.
One of my hypotheses is that human sexuality is so complicated because of over-fitting. By the nature of evolution, sex is key to trait selection. What we end up with is a brain that has been evolved to desperately find any pattern it can to help our genes replicate. This means humans (and possibly other creatures that reproduce sexually and have large brains) end up with all sorts of kinks that have no benefit to evolution. Our brains are just hoping that some of these moon-shot desires end up giving us an advantage.
A lot of these kinks ended up making sense and have stuck around. People tend to find fitter humans attractive. Wider hips are usually considered more attractive, etc. But you also have a whole field of unsubstantiated interests that stick around because they don't hurt the evolutionary drive enough to weed themselves out.
Very cool. I wonder what other evolutionary changes happened because of the rapid shift from hunter-gatherer life to farming and industry.
It's wasn't an evolutionary change. Our food is too soft, so there isn't enough force applied during our growing years for our mouths to get into the right shape.
Ah, that makes much more sense.
I am reminded of how domesticated foxes who were selectively bred for friendliness towards humans exhibited other traits like floppy ears and (notably) more brittle teeth. This only took a few generations to manifest as well, so evolution does not need to run its natural course for knock-on effects to take hold.
Makes me wonder if there’s some truth to social Darwinism wherein by no longer selecting for primal survival skills and instead prioritizing cooperation within urban environments, humans have developed other emergent phenotypes.
Put another way - our ancestors who didn't have good jaws and more perfect teeth didn't live long enough to become fossils. Tooth infections can kill, and the pain of bad teeth certainly doesn't help one eat to survive. While I agree that the evolutionary pressures have changed, couldn't there be a bias in the sample sets of old fossils because of this? Did ancient children have perfect teeth as well?
Probably less to do with fossilization itself and moreso the sheer prevalence of straight-toothed humans who live longer lives and have more opportunities to procreate and continue passing “good” dental genes
My thought was that there's just more adult to fossilize than child, since the children with dental problems wouldn't make it to adulthood.
I think this (generally) is a pretty important topic for modern medicine. How many of our species' other challenges are caused by a mismatch of evolved human psychology/physiology to the modern environment? ADHD? Back pain? Allergies? And what solutions can we find by investigating the differences between our modern built environments, our diets, our hygiene practices, etc. and those of our hunter gatherer ancestors?
Wikipedia has a pretty decent entry on the topic of "Evolutionary Mismatch", for anyone interested: https://en.wikipedia.org/wiki/Evolutionary_mismatch