″ The fourth color opsin for these animals lies in the ultraviolet. For humans such a protein must be carefully picked among existing ones (or else designed anew) since the human eye naturally blocks UV light. UV-A (320-400 nm) is likely the best candidate as a large part of it reaches the retina and there are animal uv opsins with mean responsivity at around 370 nm. ”
How does this compare to those humans who are naturally tetrachromate? Do they see ultraviolet as well, or something else? And why select something other than what they have which clearly works with human brains and eyes?
There is genetic evidence that some people might be natural tetrachromats, though as far as I know only one case has been confirmed, sort of. If this is true these people would have an additional Q type cone cell, with responsivity in the visible spectrum (so they don’t see UV). The mean responsivity of Q cells is in between M and L cells with heavy overlaps, so many of these new color qualia are also inaccessible.
I think it’d be more interesting to expand the frequencies that humans can see rather than just add a new color among the current visible spectrum. Many birds and flowers possess features with colors in the UV which we cannot appreciate right now. Also, squeezing more peaks inside the visible spectrum without expanding it might be difficult if we also want to keep these curves decetly separated.
″ The fourth color opsin for these animals lies in the ultraviolet. For humans such a protein must be carefully picked among existing ones (or else designed anew) since the human eye naturally blocks UV light. UV-A (320-400 nm) is likely the best candidate as a large part of it reaches the retina and there are animal uv opsins with mean responsivity at around 370 nm. ”
How does this compare to those humans who are naturally tetrachromate? Do they see ultraviolet as well, or something else? And why select something other than what they have which clearly works with human brains and eyes?
There is genetic evidence that some people might be natural tetrachromats, though as far as I know only one case has been confirmed, sort of. If this is true these people would have an additional Q type cone cell, with responsivity in the visible spectrum (so they don’t see UV). The mean responsivity of Q cells is in between M and L cells with heavy overlaps, so many of these new color qualia are also inaccessible.
I think it’d be more interesting to expand the frequencies that humans can see rather than just add a new color among the current visible spectrum. Many birds and flowers possess features with colors in the UV which we cannot appreciate right now. Also, squeezing more peaks inside the visible spectrum without expanding it might be difficult if we also want to keep these curves decetly separated.