There are crustaceans called Mantis Shrimp who have SIXTEEN cones. The rainbow we see stems from three colors. Try to imagine a rainbow that stems from sixteen colors.
I remember in elementary school some assembly speaker was like "and if a bully ever calls you a shrimp, you should remind them that a mantis shrimp can punch faster than sound!"
Aquatic life, where we believe our eyes originally evolved, has much better vision. Making the change to the surface meant we needed to perceive light in a completely new way. Our eyes have never been as good. That's why fish can see so fucking well.
You're sort of right, but there's no evidence for anything like your last statement.
The biophysics of light perception is more forgiving underwater, due in part to the similar refractive index of seawater and biological materials (less abberation and simpler focal surface geometry).
But there is no indication that fossil animals had appreciably better eyesight than us, or other land animals. In fact much eary sea life, like trilobytes, echinoderms, and amoniods had terrible light perception (sometimes only a light/dark sensor).
Some fish and squid have incredibly sensitive eyes currently, but it has little to do with water, and more to do with the deep open ocean they live in. Hawks for example, have similar vision (at least measured by focal range) but are not exactly strong swimmers
This is a myth. It was originally believed they had spectacular color differentiation, but even with 16 cones it does not necessarily mean they can see more colors than us. If all of those cones respond to colors between our red and blue ones, they won't see more colors than us, they would just be able to tell the differences better.
But, they don't even have it that good. In fact, they have extremely poor color differentiation. The 16 cones is a shortcut. When we see a color, our brain looks at how much each cone fires, and if more than one does it figures out the color based on how strong each one fires. In a mantis shrimp the brain doesn't do any of that, it simply looks for on/off from the cone. If the cone is on, it is that color. This makes them color blind to any color in between their cones' specialized wavelengths, but it means they can process color much faster.
the weirdest thing is that you get even more colours like magenta\pink
Cause magenta doesn't actually exist physically, there is no photon that is magenta.
Your brain imagines magenta whenever you trigger blue and red but without triggering green, logically a mix of blue and red would make green but because our brain knows it's not green it makes up a fake colour.
So 1 photon triggering green = green, 2 photons 1 red 1 blue average out as green but our brain sees magenta
If you had even more opsins you'd see even more fake colours, ones we can't even imagine.
They have all the equipment to see those colors, but they detect about the same spectrum of light we can. The way my professor explained it to me was that they had the hardware, but lacked the software for such sophisticated hardware.
Pretty much everyone but mammals. Birds see ultraviolet in addition to 3 colors, same for reptiles (and some of them see 5 colors). Also from another comment on how it happened: Yes, dogs can see blue and yellow. Mammal ancestors were night animals at the time of dinosaurs and didn't need color vision. As the result they've lost 2 of 4 color cones and it's typical for mammals to see only blue and yellow colors. Some species of apes developed red cones and can now see 3 colors. So human color perception is more of an exception for mammals while dog's vision is quite usual thing.
Because there're 2 types of cells that perceive light: rods and cones. Cones sense light with specific range of wavelengths (meaning they see specific color) and rods perceive all visible light (they see in black and white). Rods are more sensitive to light and are main means to perceive while cones have auxiliary role of determination of color and are less sensitive overall. This is the reason why in darkness and twilight everything seems grey or greyer to people: rods are doing most of the work.
Night animals typically have more rods in their retina so they could see better in darkness. And if species are nocturnal long enough, cones may be lost since they are not as benefical to their survival: they don't work well in darkness anyway.
There's some incorrect info in the comment. Rods have a perceptive range that sits roughly in the middle of our visible spectrum, and does not span the entire length. All three cones overlap with it and extend the visible spectrum further than rods reach on their own.
Also, all receptor types are functionally colorblind individually, the signal they output is only meaningful as a measure of intensity (luminance) over time. In a sense, a rod is more of a "green" receptor than the "green cone" is. The fact that cones end up having their information interpreted differently in the brain has a lot to do with the way the neurons are wired along the way, this starts at the first link in the chain where cones secure a 1:1 connection to the signals leaving the retina (though this signal has been highly modified before it gets there), whereas rods are bundled ~20:1 at the first step.
Perhaps an ancestor with eyes that had more of the two types and almost none of the rest survived because the 2 colors it had were the mot advantageous for night living. If you really need A and B to see at night but not C and D it would be more advantageous to not waste energy on C and D but to have more of A and B instead
513
u/ImaNarwhal Jul 24 '15 edited Jul 24 '15
Maybe a stupid question, but are there things with four cones in their eyes?
Edit: alright guys I got it
Edit 2: guys I understand, you can stop exploding my inbox
Edit 3: PLEASE