http://www.bioc.uzh.ch/wagner/...

It would be even more interesting if life developed the ability to perceive that which did not exist.

Wow. Then the Evangelists among our atheist brethren should stop trying to assert that people's direct perceptions of spiritual realities is all about that which does not exist.

I doubt it. Might the redness of blood have anything to do with it? Why do bullfighters wave red capes to "enrage" the color-blind bull?

If you can't see red, blood isn't red. The red capes are flashy to those of us who can see red. If the bull can't see the color, then it's the movement (and/or the matador's attitude) that enrages him.

Of course it did, so it's interesting that life had to 'develop' by means of specified mutations the ability to perceive that which already existed.

It would be even more interesting if life developed the ability to perceive that which did not exist.

More interesting that so many widely separated kinds of life ended up developing the exact same means. Almost as if it were predestined, eh?

Almost, but not quite.

Next question: Humans use the color red to express a consuming emotional state, which in English is phrased "seeing red." Did proto-people emotionally "see red" before they could physically see red?

I doubt it. Might the redness of blood have anything to do with it? Why do bullfighters wave red capes to "enrage" the color-blind bull?

So yes, "red" existed already.

Of course it did, so it's interesting that life had to 'develop' by means of specified mutations the ability to perceive that which already existed. More interesting that so many widely separated kinds of life ended up developing the exact same means. Almost as if it were predestined, eh?

I like the "Seeing Red" portion of the title of this post, and note that in Chalmers' description of the nature of qualia he uses the color red - perhaps just a coincidental choice, perhaps a quale new enough in the bank of qualia to resonate in most non-color blind people.

Next question: Humans use the color red to express a consuming emotional state, which in English is phrased "seeing red." Did proto-people emotionally "see red" before they could physically see red?

The results of this extensive study were published in March 2007 in the international journal Ecology Letters (Volume 10, pp. 290-298). In clear ocean waters, blue and green wavelengths penetrate the deepest. Here, the competition model predicts a competitive advantage for red species. In turbid water, with high concentrations of organic matter, red wavelengths dominate. This favours green species. The model predicts stable coexistence of red and green species in waters of intermediate turbidity, including many coastal waters and a wide variety of lakes. These model predictions match the data. Clear waters are indeed dominated by red species, turbid waters are dominated by green species, and waters of intermediate turbidity are characterized by a colourful mixture of red and green species."

So yes, "red" existed already.

identical amino acid substitutions

Wow! How homologous are these genes anyway? Apparenlty the amino acids are the same, how different are the point mutations at the nucleotide level?

The results indicate that the red pigments in human and fish evolved from the green pigment independently by identical amino acid substitutions in only a few key positions.

Ummm… this has already been answered by biologists, Mike. We (as primates) see red so we can distinguish new leaves and ripe fruit better than our color blind brothers. I've cited numerous papers saying this very thing in the many trichromatic vision threads at ARN.

I doubt that fish evolved identical trichromatic capabilities so they could distinguish new leaves and ripe fruit. Huh.

Question: Did "red" exist before fish, birds, reptiles and/or primates evolved the sensory apparatus to perceive it? Or did "red" come into existence when life (myriad forms) independently evolved the sensory apparatus to perceive it?

The answer to that is pertinent, I think.