It’s about evolution and function, I guess, like everything else. My thinking: Iris tint or lack (blue), does not, as far as I know, change vision, as long as the material fits with other possible variations–which, like so many others, just occurred…just because…because it could, and the odds played it that way to allow for genetic odds. But livers, or the tops of them at least, are made of something which can’t be altered in such a way. Our blood is red because heme and oxygenation produce that color (although it’s not orange like rust), and evolution worked out that oxygenation is part of the package.
Yes, right?
I was just wondering on the illustrated man approach to our insides–let alone our skin-- and what a true representation/range of what our organs look like, and thought to put the question as in subject hed.
It is capable of achieving many colors, from, well, liver color through a range of tans, browns, mahogany reds, and shades of yellow and green, depending on how its owners treat it and what diseases it comes down with (not to mention exotic coloration of tumors metastatic to the liver, like melanoma).
Exactly my point and answers I was looking for for my illustrated man. I might add that this thread is a spin-off, mentally, from the recent green-pooping of my puppy, which I thought was from a tasty soap-pad, but, as I was informed, was from an excess of green bile caused by a huge appetizer of cooking oil–which led to thinking about always checking and removing bits of gall bladder from livers I (not Hannibal Lecter) eat, and you can always found them because they’re bright green.
Note that all the variability in the colourful external bits are all down to the same set of melanin pigments whether it’s hair, eyes or skin, and are interrelated. So it doesn’t take as much variability as you’d think to get all the colour combos we express, and also pigmentation there is kind of the point.
Whereas like you said, the reds in our insides come from the haemes in the blood and muscle globins, and I don’t think you can get as much variability there without impairing overall function of any of them. But the colour is just a side-effect of their function anyway, so they can stay the default and it doesn’t matter.
There are basically two types of pigments for hair color, black and red. How much each pigment shows up determines what your hair color will appear to be.
So Black is either the most common hair colour or the least common. Ditto with Red.
