• Catoblepas@lemmy.blahaj.zone
    link
    fedilink
    English
    arrow-up
    180
    ·
    2 days ago

    It’s also orange because mammals can’t produce green pigments, so orange is the next best thing if your prey is red-green colorblind.

    • InverseParallax@lemmy.world
      link
      fedilink
      English
      arrow-up
      99
      ·
      edit-2
      1 day ago

      Our primary outer protein is basically keratin, which can be tinted orange(carotene), beige (collagen) or brown/black (melanin).

      The green pigment is a byproduct of bilirubin catabolism, which we don’t have because we use a different pathway to metabolize and recycle it.

    • Umbrias@beehaw.org
      link
      fedilink
      English
      arrow-up
      14
      arrow-down
      1
      ·
      1 day ago

      more accurately, orange pigments are readily available. Nothing fundamentally stops mammals (or anything else) from developing a green. Note for example many animals have green eyes.

      • Catoblepas@lemmy.blahaj.zone
        link
        fedilink
        English
        arrow-up
        19
        ·
        1 day ago

        From what I understand green eyes are a bit weird as far as coloration goes, as they look green due to the way light is interacting with small amounts of melanin in the iris (the same pigment that makes eyes brown) rather than due to green pigment. I’m not sure that could be replicated in fur vs in a liquid environment like with the eye.

        Birds mimic green colored pigments with iridescence (except turacos, they have green pigments for real) in their feathers, but I’m not sure that’s something mammals can do structurally in fur the way birds can in feathers.

        • Umbrias@beehaw.org
          link
          fedilink
          English
          arrow-up
          4
          ·
          1 day ago

          Both blue and green eyes in humans and blues and many greens in vertebrates are structural, yeah. Yes the structural coloring could be recreated in fur or skin. (noting that many mammals do structural IR effects in their fur, famously polar bears)

          • Catoblepas@lemmy.blahaj.zone
            link
            fedilink
            English
            arrow-up
            3
            ·
            1 day ago

            I wish I could find the sources from when I was reading about this months ago, it was more about evolution in terms of things that can happen and not ‘random’ mutations, and one of the examples was tigers with orange fur instead of green. It’s not physically impossible to have structural coloring (although the fact there are no green mammals suggests a strong inhibition somewhere along the line), but you first have to have the genetic and molecular groundwork laid to allow it to happen. Ex: it’s not physically impossible for animals to manufacture their own vitamin C, but humans just can’t do it because we don’t have the necessary molecular pathways other animals use. I hope that makes sense for what I’m trying to get at.