Now, I’m not saying that cracked is a source that should be treated as well as TSD. But, I found it interesting. And, to me, it makes more sense that humans, at least in the past 100k years, have had about the same visual ability, but haven’t had the words to express what they see.
Then, there is this article 6 Absurd Gender Stereotypes That Science Says Are True | Cracked.com and I’m looking at #2. It says that the gene for seeing red is only in the X chromosome. So, it says, that maybe some men can’t see red but women see a bit more than men by having two X chromosomes.
I’m trying to add to the straight dope article since I happened to read this cracked articles recently.
The first Cracked article is misleading, although not completely incorrect. I’m not familiar with this particular study, but it suggests that they are asking the Himba “do these two colors look the same to you?” when in reality, I would guess that they are asking “are these two colors the same term?” Later, they suggest that in Turkish and Russian, color discrimination is stronger. This suggests that the Himba can distinguish between two shades of serandu, but aren’t as good as it as English speakers. If you ask them are serandux and serandux+2 different they can’t guess accurately, but they can if it’s between serandux and serandux + 10. There is evidence for this: it is much easier to distinguish between colors on opposite sides of a color category, e.g. if you determine in one individual the barrier between blue and green, two hues that are on one side of the barrier need a larger difference to distinguish than two hues that span the barrier.
For the second article, the red cones AND green cones (they don’t mention that) are on the X chromosome. A “gene for seeing red” is also a extreme simplification, which I won’t get into. This article is mainly about tetrachromacy, which is likely to occur in some women. However, the article fails to mention whether there is actually any functional strengths in tetrachromatic human women, the evidence is sparse but not nonexistent. We cannot look at animals that have four cones and assume that humans work the same way.
As far as genetics, men are much more susceptible to some types (missing your blue cones is equal between sexes). I am not sure what their “40 percent” stat is supposed to mean or be derived from. Tetrachromacy can arise like this: although say the red cone is said to best respond to 560 nm light, throughout the population there are alleles that code for 560, 562, 564 etc. responses. A woman may inherit two alleles, one from each parent, that are different enough to create two distinguishable cones. This is why our species has green and red cones by the way, they are structurally the same, but a mutation may have changed just a few amino acids and made a 560 nm red cone change into a 530 nm green cone.
The ancient greeks certainly knew of blue. A number of statues from the period have been discovered with blue painted eyes.
They were also aware of and had a name for purple (porphyra). Theopompus in 4th century BC refers to Tyrian Purple ( πορφύρα, porphyra ) with “Purple for dyes fetched its weight in silver at Colophon”. Tyrian Purple comes from the Spiny dye-murex.
A similar dye was Royal Blue made from a related species of sea snail.
The contemporaneous Israelites also knew of blue as it was specified as a required dye color for their clothing.
Thanks for the updates! I’m sure cracked is a bit loose on some things and certainly don’t consider it a primary source but it does get me thinking about a lot!
I also thought the ancient Greeks and Romans knew other colors and thought I saw something on the History channel about reconstructing the colors used in temples and it included more than three colors.