Seems pretty dumb in our biological design to not be able to regenerate such a functional (and also easily breakable) part of our body.

  • sun_is_ra@sh.itjust.works
    link
    fedilink
    English
    arrow-up
    115
    ·
    1 month ago

    Your baby teeth and adult teeth all began developing before you were even born. Our DNA still contains all the genes that sharks use to grow their endless conveyor belt of replacement teeth, but in humans these genes are deactivated by the 20th week of foetal development.

    The advantages of keeping the same teeth through adulthood is that they can be securely anchored in the jawbone, which allows us to chew tough plants and grains.

    https://www.sciencefocus.com/the-human-body/why-cant-we-regrow-teeth

    though a drug is being developed that could allow us to regenerate teeth

    • Mongostein@lemmy.ca
      link
      fedilink
      arrow-up
      28
      arrow-down
      8
      ·
      edit-2
      1 month ago

      I disagree.

      I believe that humans were created by an ancient race of machine-men that used biology the same way we use machines. When we became self-aware we destroyed them and lost all prior knowledge.

      Now we’re on the brink of creating the next race of machine men that will destroy us only to repeat the cycle until the end of time.

    • 🇰 🔵 🇱 🇦 🇳 🇦 🇰 ℹ️@yiffit.net
      link
      fedilink
      English
      arrow-up
      6
      arrow-down
      2
      ·
      edit-2
      1 month ago

      Or we were designed with planned obsolescence in mind. I mean, we can pretty much do everything to keep a human alive for a long, long time… But the cells themselves have an expiration date and after that point they simply stop replicating. It’s like the last puzzle to solve for figuring out immortality.

      • AmidFuror@fedia.io
        link
        fedilink
        arrow-up
        1
        ·
        1 month ago

        It’s way easier to start new life after selecting amongst gametes than it is to keep an aging body alive forever.

        • Shou@lemmy.world
          link
          fedilink
          arrow-up
          8
          ·
          1 month ago

          On the contrary. Death is programmed.

          Mammals have fuck all in terms of adaptability tactics. Only way for us to adapt, is mix our genes and hope it suffices. The only way we can do that, is reproduction (funghi are op). Now that means more of us in a system that has limited resources (called carrying capacity). We die in order to prevent competing with our children.

          This is the reason animals have different lifespans depending on how likely they are to survive in nature. Take a rat and north american opossum for example. Far apart in terms of evolution and size, but have roughly the same life expectancy due to predation. Wolves can technically live up to 17 years, but become fertile at a very young age because the average lifespan in the wild is 5 years due to disease.

          It is also the reason menopause exists. It is rare, and found in elephnts and orca’s (both matriarchial species) and humans. This is because the life experience of the matriarch is too valuable. To be able to keep the matriarch around without her being able to compete with her own offspring, infertility is incuded. Post-menopausal orca’s pimp out their youngest sons because it is the best way to pass on genetics they have left. Imagine your mom being your finman.

          Humans are the odd one out here since we also have andropause, the male equivalent. A paradox on male reproductive strategy. Which afaik doesn’t exist anywhere else. This is why humans live so long compared to most mammals. Grandparents are important.

          Some animals don’t really age. Lobsters simply die from growing too big and unable to get enough oxygen. Some species of octopi stop eating after mating all the way to starving to death. Some animals mate until they die from exhaustion. The immortal jellyfish pretty much recycles itself. And bot just animals need death for renewal. New zealand has a forest which reproduces only after a forest fire. Which happen rarely over hundreds of years due to being in a region with lots of heavy rain. The trees themselves are pretty much immortal, and don’t reproduce while living.

          Senesence and death are essential for ecosysems and adaptation of life. Regardless of whether or not keeping an aging body alive is hard or possible.

          We age because our cells “choose” to. We have the equipment to live on “forever.” It’s just not our meta.

  • southsamurai@sh.itjust.works
    link
    fedilink
    arrow-up
    57
    arrow-down
    3
    ·
    1 month ago

    You said exactly why in your post: “…our biological design…”

    There’s no such thing. We evolved. That means we’re a mix of traits passed along over time by individuals that managed to live long enough to breed.

    That’s it. That’s the whole explanation for any question about “why don’t humans do x thing as part of our biology?

    Any given trait is all about lasting long enough to make babies. Once that occurs, all that’s left is a general proclivity to ensuring the babies survive long enough to do the same. Regrowing teeth isn’t part of that. It’s a niche trait that isn’t as useful as you’d think for humans. We don’t need to gnaw at things, we don’t need to crack bones with our mouths, nothing that would make a third set of teeth an advantage, or different teeth an advantage.

    Teeth are not easily breakable. We actually can crack bone with our jaws and the teeth will usually survive if the bone isn’t too thick; we just have better tools for that because way back when, the proto-humans that used tools had more babies that survived to make more babies. You have to abuse and/or neglect your teeth to break them for the vast majority. There are congenital issues where that isn’t the case, but we’ve also bred ourselves into a social species that takes care of each other, so we aren’t limited to a harsh, primitive survival level of things.

    I really don’t get why people think of teeth as fragile. They’re incredibly durable for what we need them for, and require only minimal care to last well beyond breeding age. Even if you factor in modern diets being bad for teeth, regular care for them (brushing and flossing) can stave off those effects for decades. Go search up some of the dental research on old human bodies from archaeological sites. People survived very well with just one set of adult teeth.

    And, some humans do have extras that can come in later in life, though it’s very rare and comes with drawbacks (according to the last lady I dated that was an anthropologist anyway). Supposedly, having the extras actually weakens the regular adult teeth and makes them more prone to damage. There’s always a tradeoff in things like this.

    • Granixo@feddit.clOP
      link
      fedilink
      arrow-up
      2
      arrow-down
      2
      ·
      1 month ago

      People like me have only one problem with what you just said, and it’s called “Bruxism”.

      • southsamurai@sh.itjust.works
        link
        fedilink
        arrow-up
        4
        ·
        1 month ago

        Well, if you make it to breeding age, and successfully do so, then it really doesn’t matter from a species perspective. If you don’t, then whatever traits led to the grinding are weeded out, so that’s also irrelevant to the species in a different way. Also, there are treatments to help with bruxism. It isn’t something that can’t at least be managed to reduce the speed of damage.

      • SuddenDownpour@sh.itjust.works
        link
        fedilink
        arrow-up
        3
        arrow-down
        1
        ·
        1 month ago

        Not really? Bruxism is heavily linked with stress and anxiety, which we have too much of in our contemporary society (meaning: a drop of water in our whole evolutionary history), and it’s very rarely going to incapacitate anyone, so evolution doesn’t care, and has cared even less before civilization.

  • themeatbridge@lemmy.world
    link
    fedilink
    arrow-up
    50
    arrow-down
    1
    ·
    1 month ago

    Just a note, biology doesn’t have a design. If you’re looking for some kind of logic or plan, you’ll be disappointed.

    Things are the way they are because a long time ago, it helped something survive and procreate. That’s it, survive and procreate. Every other consideration is secondary.

    We can theorize about why two sets of teeth were advantageous at some point, but that doesn’t provide an answer to “why?”

    • jaybone@lemmy.world
      link
      fedilink
      arrow-up
      2
      arrow-down
      1
      ·
      1 month ago

      But if you knew the environment, and therefore what evolution would select for, you could essentially “design” biology right?

      • themeatbridge@lemmy.world
        link
        fedilink
        arrow-up
        2
        ·
        1 month ago

        Sure. Dwarf Wheat is a great example of humans creating a plant to survive in specific environmental conditions with massive benefits. Or we could look at introduced species, like the cane toad, which are too good at surviving their new environments.

        We don’t (yet) have the biological capability to “design” an entire species from the ground up, but if we did, I’m certain our first attempt would be a collosal failure that could potentially wipe out humanity. But that’s just based on how good we are at ignoring warning signs.

  • kinsnik@lemmy.world
    link
    fedilink
    arrow-up
    37
    ·
    1 month ago

    The diet that we evolved to consume (fruits, lean meats and fibrous plants) was much less damaging to our teeth than the current high-sugar, high-fat, highly processed foods. And human lifespans was shorter, so less time for teeth to damage. So there wasn’t a strong evolutionary need to regenerate them (unlike an animal like sharks)

    • ameancow@lemmy.world
      link
      fedilink
      arrow-up
      20
      ·
      1 month ago

      This concept can be scaled up to a lot of things, like why most of our systems break down. Nature only maintains what is needed to continue the species, everything that happens to you afterwards, with the exception of child-rearing, will be abandoned by nature unless someone gains some trait from living longer that helps the species propagate.

      But nature is kind of silly, it doesn’t make “choices” so some of the adaptations can be weird. Like how our retina’s blood supply formed on the front of the retina so your brain has to always edit out your blood vessels from your vision and you can only see it using special tricks of light and then BAM all the spaghetti appears that’s been there all along.

      Imagine what else our brain tells us and shows or doesn’t show us to make sense of what evolution has turned us into.

        • ameancow@lemmy.world
          link
          fedilink
          arrow-up
          4
          ·
          1 month ago

          The idea is that if you can make your surroundings as dark as possible, then shine a very small point of light into your eye and wiggle it so there’s a shadow changing angles rapidly across your retina, this will make the blood vessels you can’t normally see shift slightly in your field of vision so your brain forgets how to edit them out and they pop into view.

          This site gives instructions how to use black construction paper with a pinhole in a dark room, but I’ve learned how to do it with a nearly closed fist and any bright light source.

          • Amanduh@lemm.ee
            link
            fedilink
            arrow-up
            3
            ·
            1 month ago

            So its kinda like how your brain edits your nose out but if you close and open alternate eyes fast it has a hard time doing that?

            • ameancow@lemmy.world
              link
              fedilink
              arrow-up
              5
              ·
              1 month ago

              Yep! Or even how you usually breath without thinking about it but can take over manual control. Your brain does a LOT of things with your senses all the time that you don’t notice, it has layers and layers of intelligence that makes decisions on what it will “report” upwards, so you depend on basically a vast system of managers or sub-officers that are conscious but have no language, to fully captain and control your meat-ship.

                • Notyou@sopuli.xyz
                  link
                  fedilink
                  arrow-up
                  3
                  ·
                  1 month ago

                  X-Men 97 recently gave me “Inferior Freak Fluids” for a good band name. Maybe we can open for you, once I learn how to play.

  • AmidFuror@fedia.io
    link
    fedilink
    arrow-up
    39
    arrow-down
    3
    ·
    1 month ago

    There are no stupid questions. But there are grammatically flawed questions.

    • kautau@lemmy.world
      link
      fedilink
      arrow-up
      26
      ·
      edit-2
      1 month ago

      Philosophical take.

      We can. We figured out how. Thousands of humans fly every day across the planet faster than any bird. We can also live in environments we were definitely not designed to whether it’s with clothing, fire, or advanced HVAC systems. And we’ve pushed that further with our own little atmospheres under the sea or in space.

      Evolution didn’t stop with us. It is us. Evolution, in trying every possible permutation landed on an organism that adapts the world around it, rather than waiting generations to adapt to the world around it.

      Now it’s a matter of if our social and societal evolution will see us succeed or end in failure. If we don’t solve the climate crises we created, if we end up murdering each other, if we get smacked by an unforeseen object from space, potentially built by even more advanced evolution, we lost, and evolution will continue. Evolution is us, but far too often we’re too blind to see that gift, and advance responsibly