Re: Anyone here colorblind?

On May 7, 1:57 pm, Greg Goss <go...@[EMAIL PROTECTED]
> wrote:
>  The gene coding for the red sensor is fairly new in
> evolutionary terms, and so only exists in one place, and in a BAD
> place on the X chromosome.  Men have no spare copy of this gene, so,
> if the only copy goes bad, you don't get red.
[...]
> (Change is not always "bad".  The red-sensing cone that is so valuable
> to fruit-eating primates is clearly a mutation of one of the several
> genes coding for blue-sensing cones.  Break it and you get something
> more useful than  the original.)

Hmmm, last time we went through this, I learned that there's a few
people out there who have 4 cone sets -- the 4th is a violet, IIRC
(and when do I do that?), but I don't remember if there is a gender
bias to it.

All 3 (or 4) dyes are very closely related, differing in some small
but significant way; something like the zinc vs iron of chlorophyll
gegen  hemaglobin.  And I think the dye molecules are recycled from
some previous non-visual usage, but the memory is fading fast, and I'm
not going to google for it right now.

/dps