[gameguy43]

Super interesting. My notes as a colorblind man (might be misunderstanding some stuff though):

(Being a little sloppy with sex stuff here. Not all women have two x’s, women can be colorblind too, etc.)

• Two of our usually-three cones are specified on the X chromosome

• When one of a woman’s X’s specifies an anomalous cone she ends up with a 4th, anomalous type of cone.

• This happens ~14% of the time for women.

• That’s about the same percent as color blindness in men.

• That’s not a coincidence. Because color blindness comes from one of these women’s sons getting that anomalous 4th come instead of a typical 3rd cone. This anomalous cone tends to overlap more with one of the other cones in its range of perceived frequencies, which is what causes color blindness.

• But only a small percentage (not sure what percent yet?) of these women with 4 different cones actually seem to be able to perceive more colors

• that’s because the 4th, anomalous cone might basically fully overlap with one of the typical ones in its perceived frequency range, so it doesn’t really give the brain any additional info

• one question I have: so it seems like not all these anomalous cones are the same. Is there a fixed number of types? Or is it more of a spectrum? Further, are /all/ cones on a variable spectrum? Or is almost everyone’s blue cone exactly the same?

• this was interesting: colorblind men actually have a set of colors they can distinguish that people with normal color vision can’t (the article explains why)

• in this study they found colorblind men (but by looking at unusual things they /could/ see, not things they couldn’t? Not sure) and then tested their mothers to see if they could see extra colors.

• Most of them couldn’t. One of them could. The study was only like 9 people? Safe to say /all/ of these women had 4 types of cones, even though only one of them had a sufficiently non-overlapping fourth one to get some benefit?

• As a colorblind man, I’ve never noticed an ability to distinguish colors others can’t. Only the opposite.

• it’s intellectually neat to know that’s possible, even if it doesn’t tend to “come up” in everyday life.

• It souuuunnndssss like the amount of extra color vision that these tetrachromats get is only the same as the extra color vision /I/ get—that same “theoretically there, but doesn’t seem to come up in everyday life” thing. That’s a little disappointing—I though tetrachromacy was more kooky.

[3pt14159]

> Or is almost everyone’s blue cone exactly the same?

I get a stronger blue channel from one eye than the other. So I'm quite sure that there is variability, it's a matter of degree. Also, research into language and culture shows that the brain is heavily influenced by colour as well. Some cultures have difficulty seeing differing shades of blue or green that westerners think are trivial.

[UnbugMe]

My favorite sex-affecting genetic incident is Androgen insensitivity syndrome [1]. People with Y chromosome who have complete androgen insensitivity syndrome [2] have fully female external bodily features; their reproductive systems are ill-developed, and they are infertile.

> Most individuals with CAIS are raised as females. They are born phenotypically female and usually have a heterosexual female gender identity; However, at least two case studies have reported male gender identity in individuals with CAIS. [2]

[1] https://en.wikipedia.org/wiki/Androgen_insensitivity_syndrom...

[2] https://en.wikipedia.org/wiki/Complete_androgen_insensitivit...

I'm contemplating a sex reassignment therapy method by provoking CAIS using CRISPR gene editing...

[3] https://en.wikipedia.org/wiki/CRISPR_gene_editing