mutants

[neph13]

I have been hearing a lot lately about a mutation that has been happening, in women, recently that has me quite curious. It's called tetrachromacy, or in other words, having 4 cones of light that enter the eye instead of the average 3. Curious! This in turn lets the person perceive colors that we cannot.

"A tetrachromat is an organism for which

Comments

[matsyendra]

I read those articles, and I remain unconvinced that human tetrachromats exist. Rather than base it on perceptual tests, they should look at their DNA or examine the physiology of their retinas. What both of these articles fail to mention is than the number of different colors a human perceives is purely cultural. Yes, the frequency range is limited by physiology -- the spectrum of visible light is literally defined by what we can see. Humans cannot see below red or above violet, although some animals can. Within that visible spectrum the frequency/wavelength of light is continuous. Yet, if you refract that spectrum producing a rainbow, most people will see seven distinct bands of color -- ROYGBIV. However those separate colors -- these arbitrary groupings of wavelengths -- exist only in our minds. They do not exist according to physics. This has been further demonstrated by studies of very isolated indigenous peoples. While we perceive red and orange as two distinct colors in the rainbow, some cultures might see three colors or only one color within the same spectrum. So it seems unlikely that the hardware addition of an additional photoreceptor (within the same range) would change what is determined by software.