90 points

And red/green color blindness isn’t less colors, you get more shades of brown.

Which sounds shitty, but invaluable for hunters.

My dad legitimately didn’t know what other people saw for “red” but he could spot a deer in the middle of the woods like it was neon yellow.

I believe the downside to tetracheomacy is less rods because the extra cones are taking up more space. Which I think translates to really bad night vision.

permalink
report
reply
21 points

Cool! I had never heard about this theory for explaining color blindness.

permalink
report
parent
reply
21 points

There’s very few things that are a flat negative evolutionarily.

Like sickle cell, in most of the world it’s a significant disease. But if you live somewhere with malaria before modern medicine, then for 99.9999% of human existence, you’d be dead at a young age without sickle cell in those places.

Or how appendix bursting was worth the risk of retaining gut bacteria. Once we got clean water, the adaption of not having an appendix started to spread. Until modern surgery took out the negative evolutionary pressure so humans will be stuck with appendixes for ever now.

permalink
report
parent
reply
3 points
*

I’m heterozygous for cystic fibrosis. It fucked my plans for having kids, cause I don’t have vas deferens. (Most people who are heterozygous don’t have any problems, but some men do with fertility). But apparently heterozygous people are more resistant to cholera and dysentery, since our cells hold onto water easier.

permalink
report
parent
reply
19 points
*

According to wikipedia, tetrachromacy is caused by having having both normal vision and red-green color blind genes in different chromosomes, so some of the red or green cones end up being receptive to a wavelength between red and green. Rods don’t sound affected.

Health line article doesn’t mention the wavelength. Got me excited that it was infrared or something

permalink
report
parent
reply
10 points

Same with my dad. He said that the military liked red/green colour blindness for spotting camouflaged stuff.

permalink
report
parent
reply
8 points

This link is very interesting. Interesting for people that are colorblind, and interesting for people that are not.

permalink
report
parent
reply
4 points

I could see 3 out of 4 of them but I’m not colour blind…

permalink
report
parent
reply
3 points
*

That’s fun!! I am not color blind and was able with a lot of work to sort of see some of them. The easiest is the second one just squint and unfocus if you wanna try. The first one I couldn’t get to work at all though

permalink
report
parent
reply
1 point

Great, I’m too color blind for the normal tests, and not color blind enough for this apparently. Fuckin dots man.

permalink
report
parent
reply
4 points

This is how all super powers work… There is always a downside.

permalink
report
parent
reply
55 points

According to about 12 seconds of googling this article feels borderline. This article specifically references a 2010 study that says 12% of women carry the gene however the article fails to mention what the study specifically says. In the opening paragraph if the study it says “However, the existing evidence is sparse and inconclusive.” & “Our results suggest that most carriers of color anomaly do not exhibit four-dimensional color vision, and so we believe that anomalous trichromacy is unlikely to be maintained by an advantage to the carriers in discriminating colors.”

I found three different studies regarding this. One said that it was about 15% of women, one said it was 50% of women and 8% of men. Another said that women with color vision defficiency and mild color blindness might have tetrachomacy effectively rendering the extra cones pointless. ANOTHER study showed that only one person EVER had been diagnosed with Tetrachomacy.

While I really appreciate media that brings to light conditions that the average person might not know about I really dislike articles and media that make things seem way more common then they are and/or portray things as fact that are far more nuanced. We already have enough people self diagnosing themselves or self identifying with abilities/disabilities

permalink
report
reply
31 points

There is a lot of misinformation about tetrachromacy and sadly this article perpetuates some of it. 12% of women are dormant tetrachromats, which means they have extra sets of cones but don’t actively use the extra ones. And the article suggests men are “less likely” to be tetrachromats, which is technically true, but misleading, since men cannot be tetrachromats at all.

permalink
report
reply
16 points

(person points to blue)

Me: blue.

(Person points to purple)

Me: blue-ish?

(Person points to aqua)

Me: blue but like… Different?

(Person realizes I just suck with colors)

permalink
report
reply
1 point

Tetrachromacy is real, and does improve the range of colour differentiation in people who have it, but the headline here greatly exaggerates the degree to which that is true.

https://www.youtube.com/watch?v=fDoAs0qN7lU

The title is predicated on the idea that 1 cone = 100; 2 cones = 1002 = 10,000; 3 cones = 1003 = 1,000,000; so having 4 cones = 100,000,000. But this is misleading, because once you have three kinds of cones, any point within the visible range has its own unique response. The 4th cone improves the ability to make fine differentiations (the examples in other comments here are fantastic demonstrations of that), but doesn’t add entirely new colours.

Sort of like how 3 towers are enough to triangulate someone’s location on a map. A 4th tower might make the triangulation go easier, or give you more confidence in your result, but it doesn’t fundamentally alter your understanding.

permalink
report
reply

Today I Learned (TIL)

!til@lemmy.ca

Create post

You learn something new every day; what did you learn today?

/c/til is a community for any true knowledge that you would like to share, regardless of topic or of source.

Share your knowledge and experience!

Rules

  • Information must be true
  • Follow site rules
  • No, you don’t have to have literally learned the fact today
  • Posts must be about something you learned

Community stats

  • 494

    Monthly active users

  • 403

    Posts

  • 3.1K

    Comments