A Chin-Stroking Mystery: Why Are Humans the Only Animals With Chins?
www.smithsonianmag.com
It's an evolutionary conundrum, and scientists are still divided over the answer
  • mearce@programming.devEnglish
    69·
    6 months ago

    TIL chins are only chins because they stick out. I had always considered the front of a lower jaw to be a “chin”.

  • Flying Squid@lemmy.worldEnglish
    683·
    6 months ago

    Of course we know why. So that evolution could result in the universe’s most perfect being.

  • Mossy Feathers (She/They)English
    7412·
    6 months ago

    This is why it bothers me when artists add chins to animalistic characters. It looks so wrong. An example:

    Like, shit. Cool character design but you gave the cat lady a chin. Cats don’t have chins, why did you give her a chin?

    • aname@lemmy.oneEnglish
      1343·
      6 months ago

      They don’t have opposable thumbs, go into night clubs, walk bipedally or have those wing things either, why is it the chin that bothers you?

      That character is mostly a cat skinned human.

      • Mossy Feathers (She/They)English
        827·
        6 months ago

        Many animals, including most felids and canids, have a fifth toe (aka dew claw), which could potentially evolve into a thumb. You don’t normally see it on domestic dogs though, because if I’m not mistaken, it usually gets cut off when they’re a puppy due to it being weak and having a tendency to get caught on things.

        Alternatively, there is polydactylism in cats, which can give them extra toes that can help them grab things (I’ve seen a video of a polydactyl cat using it’s extra foretoe like a thumb, though I can’t find it). It seems possible that, overtime, an extra foretoe like that might eventually provide enough of a evolutionary benefit for it to become a standard feature.

        If cats evolved human-like intelligence, they’d absolutely have night clubs of some kind. That said, I’m not convinced that cats don’t already have human-like intelligence and aren’t just choosing to not use it, but that’s beside the point.

        Walking bipedally is something a lot of smaller mammals can do as well, it just isn’t their normal mode of locomotion because their bodies aren’t currently designed for it. Going the evolution route again, however, and it’s possible that a species might eventually decide to stand up like humans did. Edit: I forgot about birds, dinosaurs and semi-bipedal mammals like the pangolin. Birds and pre-historic theropods walked on two legs, and pangolins have heavy tails they can use to balance on their hind legs so their forelegs are free to dig at ant mounds. So humans aren’t the only animals that walk on two legs.

        The wing things are part of her clothing.

        You’re correct that being bothered by a chin alone is strange, but,

        A) people have weird things that bother them, sometimes illogically

        B) I kinda look at anthropomorphic animals as being evolved from their real world counterparts, so I tend to rationalize things in regards to how they might have evolved. It makes it more believable for me.

        C) iirc, in the context of the movie that specific character is from, thats actually someone’s VR avatar. As such, it makes sense to make human concessions like opposable thumbs, five fingers and toes (cats technically have five toes on each forepaw, four toes on each hind paw), walking plantigrade, etc. A chin seems like an odd concession to make. From the article, it doesn’t really give humans any really evolutionary advantage so it’s not like you’re gonna be unable to do something because you don’t have a chin; and based on what I’ve seen in the furry community, chins on anthros doesn’t really seem to have much of an aesthetic appeal either (otherwise nearly every fursona would have an obvious chin).

        D) It just looks weird. Idk man, it just looks weird to me.

        That said, I don’t tend to mind hybrids or mythical creatures like gryphons, dragons, dragon-cats, or whatever, so idk. It just looks weird to me and I guess the thing about humans being the only ones with chins is a explanation and justification for why I find it weird-looking.

        • Zess@lemmy.worldEnglish
          564·
          6 months ago

          That’s a lot of words just to try and justify posting a picture from your furry porn collection.

        • aname@lemmy.oneEnglish
          31·
          6 months ago

          You answered your own question in your own question. Cats could potentially evolve a chin just like they could evolve an opposable thumb

    • odelik@lemmy.todayEnglish
      191·
      6 months ago

      You’re complaining about a chin on an anthropomorphic cat woman that only has 2 breast’s instead of 6 to 8…

  • erp@lemmy.worldEnglish
    573·
    6 months ago

    If I am not mistaken, according to the grammatical scrolls, having a chin makes everyone … chinese

  • jimmydoreisalefty@lemmy.worldEnglish
    405·
    6 months ago

    “If you’re looking across all of the hominids, which is the family tree after the split with chimpanzees, there [are] not really that many traits that we can point to that we can say are exclusively human,” Duke University’s James Pampush tells Robert Siegel for NPR. “[T]hose animals all walked on two legs. The one thing that really sticks out is the chin.”

    One of the most popular ideas is that our ancestors evolved chins to strengthen our lower jaws to withstand the stresses of chewing. But according to Pampush, the chin is in the wrong place to reinforce the jaw. As for helping us speak, he doubts that the tongue generates enough force to make this necessary. A third idea is that the chin could help people choose mates, but sexually selective features like this typically only develop in one gender, Pampush tells Siegel.

    The spandrel hypothesis is as good a theory as any, but it too has its problems. It’s hard to find evidence to test if something is an evolutionary byproduct, especially if it doesn’t serve an obvious function. But if researchers one day do manage to figure out where the chin came from, it could put together another piece of the puzzle of what makes us different from our primate and Neanderthal cousins, Yong writes.

    • andyburke@fedia.io
      34·
      6 months ago

      The dismissal of a sexually selected trait just because it usually is far more pronounced in one sex than the other seems extemely premature to me.

      I would argue chins are actually already quite different between the sexes - to the point where people will have surgery to change their appearance if their chin doesn’t conform to societal ideals.

      Sexually selected trait seems like an avenue of research that shouldn’t be so easily dismissed.

      • No_Eponym@lemmy.caEnglish
        1·
        6 months ago

        hard to find evidince

        This is, like, an undergrad project.

        1. work with the depressed grad student who is good at stats to determine the parameters of your experiment at the outset and calculate the number of subjects and stimuli for statistical power; pay in marking or research help.

        2. get an appropriate number of headshots from undergrad males for stimuli, give them intro psyc course credit for participating.

        3. work with mid-degree graphic design students to give all headshots 3 levels of chins (low, normal, emphasized), ensuring none are comical; the the psyc grad student signs off on the work as portfolio credit

        4. have an appropriate number of undergrad cis-het women subjects rate a your lineup for attractiveness; intro psyc course credit for participation

        5. analyze the results to see if low chin is selected less than normal or emphasized.

        6. submit your research paper and results; get your 4th year class capstone. Grad student takes your work and adds it to their dissertation, you get a footnote.

        I’m sure this has been done…

        • Azzu@lemm.eeEnglish
          2·
          6 months ago

          I don’t have a source on hand, but I’m sure that a pronounced chin has been found in studies as male attractiveness symbol

  • FiniteBanjo@lemmy.todayEnglish
    354·
    6 months ago

    I figure walking upright made being hit from below more common, necessitating thicker bones to protect the very sensitive nerves of the jaw.

  • OldWoodFrame@lemm.eeEnglish
    24·
    6 months ago

    The “spandrel hypothesis” is the front runner explanation. Essentially we didn’t evolve to have chins but rather evolved other things that are helpful, and the chin is a byproduct of that other evolution. Not harmful so it didn’t get selected away, but not helpful.