> f. Nipples are useless in human males (cf. Ch. 5).
When I was a kid, I got my tonsils removed "because they were useless and a source of illness".
I've recently heard that tonsil removal is now more disputed: it may collect filth, sure, but it may also prevent it from going deeper into the body, which may cause more serious illnesses.
Given its vast complexity, and the timeline of its creation/evolution, I remain skeptical over bold claims about the human body. It's really missing an "as far as we know." The ability to go beyond what is known is paramount to the progress of science, and historically attested with some intensity (e.g. Earth's shape, relativity with time/space & axiomatic geometry). Humility thus feels like a better posture.
Who would let a junior dev trim bits, or boldly modify a decades old codebase?
I narrowly avoided tonsil removal as a child and I'm glad I did, it sounds like the science rotated around to them having a rather important immune function after all.
I suspect the next round of backpedalling will be around the current wisdom teeth removal fad.
There's also a difference between having no immediate use, and having no reason to exist. From what I understand, sexual differentiation works by having the Y chromosome act as a switch, and both sexes have to share the same blueprint with hormones guided the development of their organs.
For males not to have nipples, they'd need to be actively destroyed, which poses a risk for females to also not have nipples, which is much worse than males having harmless, inactive nipples.
It doesn't seem like eliminating nipples should be any harder than eliminating the uterus...
That's true, but inactive nipples don't cost anything, which certainly isn't the case for an inactive uterus. I don't know how it works, but I assume that such developments follow some kind of cost-benefit function.
Not nipple related per se, but males do get breast cancer.
And, in weird circumstances, men can lactate. There's even a story about a viking whose name is escaping me who nursed his son after his wife died.
Aren't nipples pretty recent? The egg part has been there for a very long time, nipples haven't evolved as long, maybe in a few hundred million years we no longer have nipples.
afaik they serve some purpose in regulating androgenic-estrogenic hormone production.
The amount of testosterone in women is not zero, likewise the amount of estrogen in men is not zero as well, and breast tissue does serve some purpose in regulating hormoe production, even in men.
male and female sexual organs are the same thing inside out of each others, to some extent.
The actual switch (in humans and I believe most mammals) is a gene called SRY. The Y chromosome is just the (usual) container for the switch.
>Given its vast complexity, and the timeline of its creation/evolution
I will just say, the human body in particular has only been around for a vanishingly short period of time in evolutionary terms. A lot of the quirks and arguable flaws identified in this piece (painful childbirth through the pelvis, back pain) and others (varicoceles in the left internal spermatic vein, hernias, other pelvic floor disorders) can be attributed to our very recent move to full bipedalism.
If we’re talking about features we share with other mammals or even other primates, sure, they’ve probably stood the test of time for a reason. But for features that have only really been in existence for a couple million years, those I don’t think we should treat with the same kind of reverence.
> human body [...] has only been around for a vanishingly short period of time in evolutionary terms.
"as far as we know." Every few years, I see in the headlines stuff like "oldest 'human' ever found in X." The theory of evolution itself has morphed since Darwin [0], and is probably far from being in its definitive form.
The timeline remains astronomical w.r.t. a human life, and the perception of a single human. A few centuries ago, we may have burnt people for proposing something like the theory of evolution.
> [...] can be attributed to our very recent move to full bipedalism
Admittedly. But it's still not contradictory with this still having unknown roles. Actually, multi-causality feels like a good way to ensure the stability and solidity of a design: "don't put all your eggs in the same baskets", portfolio diversification, etc.
Thinking about painful pregnancies and birth, [1] hints at the "need" for pain/discomfort. If it's indeed some sort of a necessity, then it may be more of a feature than a bug for us to experience pain directly, through the womb, etc.
[0]: https://en.wikipedia.org/wiki/History_of_evolutionary_though...
[1]: https://en.wikipedia.org/wiki/Behavioral_sink
> as far as we know." Every few years, I see in the headlines stuff like "oldest 'human' ever found in X."
The discovery of older humans does not respond to the point you’re arguing against — in evolutionary time scales, humans are recent.
> The theory of evolution itself has morphed since Darwin [0], and is probably far from being in its definitive form.
Fields continue to change as they grow older, but the magnitude of changes tend to get smaller. Of course evolution will change, but it would be very surprising to have large changes in the fundamental elements
> Thinking about painful pregnancies and birth, [1] hints at the "need" for pain/discomfort.
Evolution only optimizes for what results in dna being passed on. It doesn’t care about ancillary details. I think painful childbirth pretty much shouldn’t matter much to evolution, because the parents have no control over the birth at that point — it’s happening one way or another. Perhaps it promotes bonding with the child, or something like that? But in general, I think it’s wrong to say “evolution provided X, so X must be needed”. If X has no significant effect on the passage of dna, then it could just be random noise.
> The discovery of older humans does not respond to the point you’re arguing against — in evolutionary time scales, humans are recent.
I meant, evolutionary time scales themselves are subjected to accuracy issues. The measurements techniques themselves are subject to accuracy issues as well.
> but the magnitude of changes tend to get smaller
Agreeing with the tendency, but there are great exceptions; physics comes to mind. The fact that we still don't properly understand QM, and physics being conceptually at the root of many sciences, a proper understanding of it may force to revisit a few things "up there".
> I think painful childbirth pretty much shouldn’t matter much to evolution, because the parents have no control over the birth at that point
Sorry, I (genuinely) don't get the argument.
Regardless, I saw articles [0][1] linking (minor) DNA alterations to exercising. It'd be interesting to see how body stresses in general could impact DNA, and how this would wrap up with evolution.
> then it could just be random noise.
Well, the problem with "noise", is that from the outset, we can't know distinguish between "actual noise" − assuming such a thing exist − or if it's merely a reflection of ignorance. The latter at least gives us direction in which to search stuff. So "evolution provided X, so X _may_ be needed" I guess
[0]: https://www.nature.com/articles/s41514-025-00217-0
[1]: https://cordis.europa.eu/article/id/34391-scientists-discove...
> I've recently heard that tonsil removal is now more disputed: it may collect filth, sure, but it may also prevent it from going deeper into the body, which may cause more serious illnesses.
Hasn't it been settled for a while that they're part of the immune system? Wiki is clear [0] on the subject; they're there to repel bacteria. They're quite important and removing them, unless there is no other choice, seems like a terrible idea.
[0] https://en.wikipedia.org/wiki/Tonsil#Function
Happened to me in the 90s (France). Seems to still be practiced regularly [0].
A 2022 article [1] quotes an ENT advocating it for kids with frequent (3 to 4) bacterial throat infections in winter.
It's often difficult for new ideas to get through people who have upheld the same point of view for decades though. Especially for "selective" fields like medicine (ego issues are probably more developed than in less selective fields). Let alone in fields strongly impacted by money or politics.
[0]: https://www.idref.fr/234378662
[1]: https://www.santemagazine.fr/sante/maladies/maladies-infanti...
> Who would let a junior dev trim bits, or boldly modify a decades old codebase?
"Chesterton's Fence": you shouldn't tear down a fence (or a piece of code) until you understand exactly why it was put there in the first place.
Chesterton’s Fence is a thing because a fence is something that was definitely placed with intent. It’s possible the intent is no longer applicable or was just plain stupid, but it didn’t happen by chance, so you need to make sure the original reason no longer applies.
Nothing in the human body was placed with intent. It’s still important to understand what it does before you go messing with it, but it’s a very different sort of thing.
Can you explain the fundamental difference between our intent and the intent of, say, a molecule in our chain of evolution? Is it free will? Because that debate hasn't been sorted out yet.
The difference is intelligence, which might be a better word than “intent.” A fence was built by someone with some measure of intelligence. An evolved feature is randomness combined with selection pressures, and sometimes it’s only there because it’s not sufficiently detrimental to be selected out.
Ok, intelligence is better than intent yes. But intelligence doesn't have a good definition and most people would say that it exists on a continuum. And when thinking of human-designed products, you can also say that there is selection pressure, and features can be selected out, etc. So I don't think there's a fundamental difference here.
My doctor has (with case by case exceptions as needed) a general rule to encourage a conservative approach: if at all possible, attempt to leave with everything you arrived with
Just like clergymen used to omit "we believe x, y, or z" when making some mystical claims, "scientists" of today omit "as far as we know from their communication with the layman...
>Who would let a junior dev trim bits, or boldly modify a decades old codebase?
Ones who does not understand the idea of the "Chesterson's Fence"
similar story with the appendix.
Initially considered a useless vestige, now thought to be involved with maintaining gut bacteria.
And yet has no discernible positive effect on modern human survival rates but one of the most acutely lethal negative ones.
Pre-medicine you got appendicitis and just died painfully.
Let me defend ear twitching. It's a subtle way of communication for those of us so blessed with the ability.
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