Mutants among us! Humans With Super Human Vision!

[Darth Wagtaros]

There's a cultural element to the way we define colours, so these tetrahedrons have no way to express what they see differently. What we see as shades of the same colour may be defined as a totally different colour elsewhere.

For example, it has been posited that the ancient Greeks did not register blue as a colour, for example; it does not mean they couldn't see blue.

From Wiki:

The Ancient Greeks made little use of the colour blue, except as as a background for the white figures of the friezes of the Parthenon and other temples. Their palate of primary colours was composed of red, yellow, black and white. They also had no clear definition of what blue was; The Greek word for dark blue, kyaneos, could mean any dark colour; not just blue, but also violet, black, or brown. The ancient Greek word for a light blue, glaukos, also could mean green, grey, yellow, or light brown.

Homer used the term "wine-dark sea" implying it may have been perceived at the time as in the red spectrum.

After all, who hasn't had that childhood/drunken/stoned argument with a friend about, "How do I know that when you see red, you see it the same as me, man"?

Well said.

More importantly, unless they can shoot lasers out of their eyes who gives a fuck?

[DGuller]

De Vries never wrote about four-coned women again.

Thank God for that. 

[Scipio]

First!

This sort of shit is completely unacceptable here.

But totally hilarious once in a blue moon, like a 'your mom' joke at your 20 year high school reunion.

[jimmy olsen]

I would assume it would for women when they were gathering fruit and such. That's why old world monkeys evolved 3 cone color vision. The side effect is that men are more likely to be color blind if their mother has this trait, I'm not sure how detrimental that would be to hunting.

You do realize that men foraged as much as women, and women hunted (albeit mostly smaller game) as much as men... 

Not every trait has to have an advantage, they can just not be so devastating as to not be bred out.  In the case such as this, it is often better to chalk up such variations to diversity that has no benefit now, but might if conditions change.

-edit -  Leggy would know more than I do, but it seems that too often we assume either a direction to evolution or a simple cause and effect that often really hasn't been there.

You of course are right, but the null hypothesis just isn't any fun.