6d ago

YOU HAVE NO POWER HERE

119 comments

This is one of many reasons the perfect eye argument by creationists is utter bullshit.
- Ugh that drives me crazy. The human eye is a perfect example of observable evolution. Organisms exist with every stage of eye development, from a photosensitive spot to a more advanced convergent evolution of our eye. And the human eye is poorly designed for it's current use, resulting in a significant percentage of people requiring corrective lenses.
  
  most of the dipshit "the eye is to perfect to have evolved" people also have cheap optics on their rifles. something to think about
  
  It's a good example of evolving towards a local maximum then being unable to travel through a valley to a more optimal design. As such it confirms exactly what evolutionary theory would predict, and not what "intelligent design by an omniscient creator" would predict.
- Clearly this means God’s chosen are the cephalopods.
  
  🧑‍🚀🔫🐙 Always have been.
  
  In the lore of Lord of the Rings, it is said that the supreme being of that universe personally created both men and elves and since men were his favorite creations, he gave them the gift of... having pretty short lives (wow, thanks). Well, octopuses have a much shorter lifespan than us, so if our universe's creator is anything like the Middle Earth's then there's a good chance they are his favorites.
- As someone with chronic back pain, eyes are the least of my issues with creationists theories
  
  exactly, bananas - amirite?
- Yeah, my eyes are so perfect, I read that as 'cartoonists' and spent a good few minutes confused.
- Bbb-but the bananas fit my hands!
- Relevant video: https://youtu.be/2X1iwLqM2t0

This arrangement actually optimizes color vision in the daytime and night vision at night. Evolution selected for the correct arrangement for those of us living on land:
https://theconversation.com/look-your-eyes-are-wired-backwards-heres-why-38319
- This is just saying that the glial cells help make this less bad than it could be, no? Nothing about why neurons behind receptors would be worse
  
  No, glia support neurons; they do things like redirecting blood flow to more-active-than-usual neurons, mylenate axons, etc. They wouldn't form a mesh around neurons' photoreceptors the same way they do neurons' somas and axons. What the article describes is that glia actually are critical at allowing for color vision during the day and night vision at night, since on land we'd get too much blue light to see color with much fidelity were it not for glia, and a similar filtration process helps us see at night. It's not that it's not as bad as it could be, it's actually that vision is better this way (barring one small blind spot outside of our fovea--which, being outside of the fovea, would have low acuity anyways).

Because of this we have blind spots, one for each eye. They are not usually noticeable because 1) the blind spot of one eye can usually be seen by the other, and 2) the brain fills in the gap.
So with this I will perform a magic trick, I will make your thumb disappear: Close your left eye and with your right look at a spot in the background, make a thumbs up gesture and place the tip of your thumb on that spot, move your thumb to the the right continuing to look at the spot in the background, when your thumb moves about 15 cm your thumb should disappear.
You can use your left eye too, just switch the directions.
- It's way too late at night for all those directions, somehow ended up creating my own blind spot by sticking my thumb in my bum.
  
  Well, I guess your thumb disappeared.
  I can try another way the blind spot is about 15 cm at arms length to the right of the right eyes center of vision. So put your thumb there and it should disappear
  
  At least your dick didn’t get stuck in the toaster.
- the brain fills in the gap
  To expand on this, current leading theory (predictive processing) says that brain first generates a visual image then confirms it with inputs and if there's no input to confirm/deny the halucination it's just accepted as is. So we can have a whole load of blind spots in all of our sensors and continue functioning rather well with an ocassional artifact.
  
  I think about this at night when my eyes are forced to attempt to make sense of the low light levels in a dark room. I know my room isn't grainy and grey-scale - that's just the best my eyes and brain can do at night. It's interesting to look around and try to imagine the proper colors and shapes of things, reckoning the difference between what I know and what I see in the moment.
  With our brains constantly making things up to explain gaps in information, it's no wonder kids think they see "monsters" in the dark. It's also no wonder that nightlights work well to keep said "monsters" away.
  
  AI witchhunting crowd hates this one simple trick !
- Woah, i didn't know that the effect would be so drastic. I want to point out to those struggling to get it to work that, as diverging mentioned, your arm needs to be fully extended. Also, the blind spot is about a thumb's width, at least for me, and is only visible at a specific x/y axis location. Any deviation from that single spot will cause it to stop working. I could tell I was close to the spot when parts of my thumb would disappear, and just had to slowly move it around until I found the spot that looked like the thumb was gone completely.
  
  Thanks you helped me see it (or not see it I guess)
- I couldn't make it work. But I did notice that the spot in the background changed focus a tiny bit at one point. I suspect my brain was tracking the thumb and simply refused to continue to truely focus on the background spot. I tried and tried, but just couldn't make it happen. Neither eye. :(
  
  Found the cephalopod
  
  Make sure to hold it at arm’s length, if you weren’t already. If it’s close to you it’s too big to vanish into the blind spot.
- It looks like there's just a gap in spacetime or something.
  By the way, your eyes are not meant to track your thumb when doing this, you have to keep still and move only your thumb for it to work, so don't move your eyes.
- Succeeded, thanks! That’s uncanny!
- What is a "spot in the background"? Like where exactly
  
  Anywhere. It makes it easier, if you have a dot or a feature to look at, but really it's anywhere in the distance. I guess generally straight ahead.

More mindflayer propaganda.
- ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn and so on

✅ Discount number of limbs
✅ Cheaply made eyeballs
✅ Held together with a bunch of inflexible bones
Wait, am I just an off-band octopus?
Damn.
- just one brain

I wonder if that afforded some level of protection to the surface dwellers' receptors when in direct contact with high levels of sunlight.
- As usual with biologists, if they do not understand what it does they claim it's a useless byproduct of evolution. A few years later they discover there is actual purpose to it, and it is actually pretty nifty. Rinse and repeat.
- I have heard the theory that it evolved this way for higher UV protection that was not needed in underwater organisms. Curious if it was really that much of a competitive advantage though.
  Edit: okay more recent studies show not so much protection but basically filtering and redirecting light so out eyes can see better color on land. See this comment: https://lemmy.world/comment/18892927
  
  See this comment:
  cheers, thanks for that!
- Wonder what would happen if an octopus looked directly at the sun
  
  Or an oarfish or anything from the midnight zone that actually has eyes

convergently evolved eyes, cephalod pod eyes evolved very differently from tetrapods. cephalpod eyes evolved by forming an invagination of those tissues. whereas the tetrapods evolved as extensions of thier brain.
plus cephalopods eyes are more like a camera, the lens move back and forth, instead of changing shapes. they do have exceptions which allows them to simulate eyes of tetrapods. they also possess the ability to regenerate thier eyes too.
- Having a larger focal point farther back from the aperture should also reduce parallax, I crease field of view and improve depth perception.

I am biology illiterate. Explanation please.
- Cephalopod precursors evolved eyes and then brains developed from the eye so their eye is structured correctly.
  Vertebrate precursors evolved the brian first and the eye evolved out the brain as a sensory stub. So it's upside down and inside out like in picture.
  The nerve cluster goes through the back of the eye splits and folds back to end in light receptors. Light hase to go through the nerves before hitting the sensor.
  There is even a reflective layer after the sensors that gives the sensors a second chance at picking up the light. This is what causes the red eye or green eye you sometimes see in flash photography.
  It would require a genetic rebuild to fix this and the intermediate steps evolution usually use would be so disadvantageous they are selected against. So the right combo of mutations to give us a working octopus eye is VERY unlikely to happen.
  
  Hypothetically, if we managed to make a genetically modified human with the eye that you are talking about, what advantages/disadvantages would it have over our current eyes?
  
  Is this at all related to why the part of the brain that does visual processioning is way in the back? Or is that a dumb question
- Octopuses don't have a dead spot in the eyes I guess
- Scallops, oysters, mussels and clams have anywhere between 40 and 200 eyes. https://en.wikipedia.org/wiki/Mollusc_eye

Shit just evolves. It doesn't evolve correctly or incorrectly.
- Evolution likes local maxima. Getting out of them is difficult. That's what the OOP meant with "evolution was powerless to correct it".
  Getting out of local maxima means you first have to go with a worse setup until you get to a new, better local maxima. That's why evolution doesn't really do that all that often and instead prefers small optimizations.
  (I use "like" and "prefer" not to say that evolution has goals or emotions, but to say that that's what the "algorithm" of evolution leads to.)
- That explains the platypus.
  Or as an old classmate told me in college: the platypus is proof that nature has a sense of humor.

https://en.wikipedia.org/wiki/Cephalopod_eye
(At a glance, this article needs some touching up and hasn't been meaningfully contributed to in some years.)

Quick way to find your blindspot:
Close your right eye
Hold your phone/monitor 1ft (30cm) away from your face
Look at the 'x' below with your left eye
Slowly bring your phone towards you (or your face towards the monitor) until the '.' disappears
undefined

. x
- Well
  It doesnt
  
  Your username says you're an owl, but you're suspiciously squid shaped
  
  God I love Splatoon character design
- The . is not visible to me at any distance without taking my eyes off the x
- The '.' never disappears???
  
  Same with me. Are we cephalods?
  
  Make sure to keep your left eye looking at the 'x' the whole time. The '.' should only be in your peripheral vision.

- Lol, at first glance I thought this was a poster for some new movie. All we need to do is change the font of "Cephalopods" to something exciting, and arrange the listed species as if they were actors' names.
- Not sure if all but at least 7. - 10. are extinct.

Do I understand correctly that our ancestors had left the water before this upgrade dropped for fish?
- I don't think you understand correctly. The cephalopod eye and the fish eye (which includes tetrapods) evolved independently.

I've said it for years, as soon as it's commercially available I'm getting photoreceptors realignment surgery.

This is the meme that set off Cylon Number Three (aka John Cavil) and eventually lead to the attack on the 12 colonies.

Is this something we could like, fix?
- Uhhhh gonna say we could theoretically, but I imagine the brain has evolved a bunch of other subfuntions to make this work.
  Though I bet you’d adjust super fast if it were only a visual change since our brains are great at adapting
  
  Cephalopod eye transplant!
  I wouldn’t be surprised if the brain could figure out how to use a cephalopod style eye, especially if it was given young.
- Geordi eyes.
- Why, is it broken?
  The workaround is good enough for now.

If vertebrae don't have it, it means they don't need it.
- that's not how evolution works. Evolution is not able to produce global maxima, only local maxima.
  
  Not really. Needs is a fairly strict word. If it was needed they would not survive without. Useful, i agree with you
  
  Dont they eventually produce global maxima by iterating towards it through the many degrees of freedom allowed by crazy mutations and time?
- No, you are 100% wrong.
  
  no they're not. by definition if you don't have what you need you don't survive. we definitively don't need it. or at least haven't for millions of years. that's different from saying we wouldn't benefit from it.
  although that's not a guarantee either. more information isn't always better.

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