You must log in or # to comment.
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.)
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.
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
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?
No blind spot and probably better light sensitivity. But it’s not like we really need higher light sensitivity as land-dwellers.
better light sensitivity
I like to think of it as “colors and light so brilliant and pretty it’s like tripping shrooms”
It says vertebrae wouldn’t that include cats who have insanely utilitarian eyes
It does, but their eyes still have blind spots and their eyes could possibly be even better if their photoreceptors were oriented towards the incoming light.
Hypothetically, what would be the advantages of “correcting” this evolutionary mistake in humans?
No blind spot and better light detection. The light having to pass through the nerves causes a lot to be lost.
Bragging rights
I believe no blind spot, which is the place where all the nerves bundle together and pass through the sensing layer, leaving a hole in our vision (the brain works hard to hide this hole from our perception, but it’s still there and can cause accidents) Also maybe better vision in general?
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
I wonder if that afforded some level of protection to the surface dwellers’ receptors when in direct contact with high levels of sunlight.
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
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
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.
This is the meme that set off Cylon Number One (aka John Cavil) and eventually lead to the attack on the 12 colonies.
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).
Couldn’t a neurons-behind-eyes human just have fewer blue receptors? Or a brain that attenuates the blue signal?
This is one of many reasons the perfect eye argument by creationists is utter bullshit.
Bbb-but the bananas fit my hands!
Relevant video: https://youtu.be/2X1iwLqM2t0
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.
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.
most of the dipshit “the eye is to perfect to have evolved” people also have cheap optics on their rifles. something to think about
The ones I know spend more on those optics than they spent on the rifle.
good for them. that’s what you’re actually supposed to do. that is, however, not the norm with conservative chuds. most will drop kilobuck or more money on an AR platform, and then shoot for shit with it because they don’t have a good enough scope to utilize their high precision barrel.
You’re just jealous of GWOT surplus carry handle mounted AR optics because they remind you how evolution didn’t grace you with eyestalks 🐌
Ain’t none of them there wanna be ‘high speed, low drag operators’ would be caught dead with a carry handle on them cheap ARs. They want to festoon them with rails to mount all the bling they think they need. A carry handle would only get in the way.
They have taken what was meant to a lightweight 6 1/2lbs handy little carbine and turned it into a 10lbs+ monstrosity.
It’s called a carry handle not an optic handle, God would never create such an abomination checkmate theists.
I wish i had eye stalks.
😭
As someone with chronic back pain, eyes are the least of my issues with creationists theories
exactly, bananas - amirite?
Clearly this means God’s chosen are the cephalopods.
🧑🚀🔫🐙 Always have been.
🧑🚀🔫🔫🔫🔫🔫🔫🔫🔫🐙
Always have been.
😮🫘🫘🫘
Always have beans.
🫡 👖 👖 👖
Always have Jeans.
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.
It’s been a while, so correct me if I’m wrong; but isn’t the gift moving on to something else after a mortal life? If I recall correctly, elves are stuck in the physical world forever. Even when they die don’t they just go to some limnal place for a while then come back?
Essentially, yeah.
Elves’ spirits either linger in Middle Earth or go to the Halls of Mandos in Aman. After some period of time, they can be re-embodied if they choose.
The souls of men did not linger, they were called to the Halls of Mandos upon death. Their souls would stay for a while in Mandos, separate from the elves, until they departed the Halls to only Eru knows where.
until they departed the Halls to only Eru knows where.
Isekai followup when?
Recycling without memory wiping? What a lazy ass.
isn’t middle earth wholly explicitly our earth? and thus eru iluvitar is explicitly the creator of our earth.
Yeah, my eyes are so perfect, I read that as ‘cartoonists’ and spent a good few minutes confused.
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.
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
. x
The
.is not visible to me at any distance without taking my eyes off thexWell
It doesnt
God I love Splatoon character design
Your username says you’re an owl, but you’re suspiciously squid shaped
I mean they look like a kid to me
The ‘.’ never disappears???
Same with me. Are we cephalods?
Ọ̶͍̖͇̔ù̷̡̗̠͚̤̲͆̆͆̈́̒͂̑̇̈͆r̶͔͔̘̣̪̻̽͆͗ ̶̡̢̢̠͈̲̪̜̘͔͇̟͐̒̑̿͐̈́͌̾̌͐̌̂̃̐͜ͅͅt̷̛̻̫̺́̈͂̓̊̔̈́̈́̀į̶̨͔̣̣̫͖̭̀̏͂̈́́̅̀̂̐̚͘͜͝m̴͇̘̼̻͔͍͚̍̏̽͛̋͛̃͠ͅe̶̜͌̾͒͒́̽ ̶̣̙̻̪͓̒͊̍a̵̭͔̝̣̙̠͇͎͈̺͋̈̇̓͐́̆̈́̈́͐̚ͅp̷̪̮̯̗̰̮̣̩̭̎̓̃̓̚̕͜͠ͅp̷̢̡̙͙̯̹̪͚̘͙̯̰̏͜ř̴̦͎̓͐̄̈́̽̔̇̈́̚̕͝͠o̴̢͍̘̹͎̹͝a̷͙̻̹̯̭̲̩̅̀͆͊̂̏̕̕͝c̴̮̎͑͛͝͝h̵̢͙͇̣͒͒̊̀̕̕͜ė̶̛͇̈́̈́̀͊̈́͛͋̊͂͗̀͋̒ş̵̧̛̘͙̬̯̰͎̖͇͚͖͂̅̔͋͋̏̏͘̕͝͝͝ ̷̢͍̺̣͉̬̹̣̲̪̽͒̏̆̄̆̂͗̒͐̃͛̚b̴̪̤͉̯̲̦̒̊̉͆͑̀̌̊̕r̴̢̢̺̬̜̦̘̪̅͌̐̓̎́̈́̋̈́͛̑̒͘ò̶̳̼̯̻͕͖̹̖̔͜͠t̵̛̖̫͓͎͚̙̀̂̀̃͛̎̅̌̆̇̚̚͠͝h̶͓̟̻̫̲͚͂̇̐e̶̩̻̗͎͎̞͇̠͎̦̊͗͝ȑ̷̢͕̣̳̪
Make sure to keep your left eye looking at the ‘x’ the whole time. The ‘.’ should only be in your peripheral vision.
It’s in my peripheral and it never disappears, I had no issue understanding the instructions.
-
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.
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)
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.
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 !
Succeeded, thanks! That’s uncanny!
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.
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.
✅ 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
More mindflayer propaganda.
ph’nglui mglw’nafh Cthulhu R’lyeh wgah’nagl fhtagn and so on
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
Need requires context. “if they don’t have it, they don’t need it to survive”. And survival is conditioned upon the environment. If something emerges that exploited the blindspot, then we’d need it to survive.
What was the evolutionary pressure that caused receptor orientation to be different in cephalopods that vertebral animals didn’t encounter? Or did they encounter it and have other adaptations that allowed it to deal with them.
Dont they eventually produce global maxima by iterating towards it through the many degrees of freedom allowed by crazy mutations and time?
There’s no guarantee that an evolutionary search process will lead to a globally optimal solution. It’s the same thing with evolutionary algorithms in computing
The problem is that the landscape of where the global maxima are changes faster than evolution can keep up. If the environment were entirely static, then yes, mathematically speaking any random optimizer would eventually reach a global maximum. However, it could take, say, 1050 years or more to jump from a local maximum to a distant, higher maximum.
Ah good point, thanks
Imagine an alligator. Quite good at catching prey with their current anatomy.
An alligator that shoots laser beams for tracking and bullets would be even better. There’s however no path from their current anatomy to this state, regardless of the randomness and timescale for mutations. In fact, in order to achieve this higher state several non advantageous intermediates would be necessary and therefore never selected for.
So no, evolution can’t achieve global maxima, it can however optimize the shit out of what it’s given to work with.
There needs to be pressure for animals with a mutation to reproduce more or animals without the mutation to die before reproduction. Like a disease for example. Otherwise the genes don’t spread and just disappear in the soup of all that species genes and never become dominant. Without any evolutionary pressure the mutation will only spread in one family and probably be gone after a few generations. Like there are human families that are more likely to produce offspring with 6 digits on their hands, but since it isn’t more advantageous than 5 digits (6 digit people don’t produce more offspring and 5 digit people aren’t more likely to die before reaching reproductive maturity) that mutation doesn’t spread across the entire species. Sure if you could sample the genome of every human on earth and identify every advantageous gene mutation you could build the ultimate human DNA. But that’s artificially created, something like that will never happen through evolutionary pathways.
No.
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.
Okay true, but I still feel the comment was misleading. If it were phrased as “If vertebrae don’t have it, it means it wouldn’t improve their fitness” it would be wrong. I’ll admit that the comment as worded is true, but it does depend on a very literal interpretation of what “needs” means. Why even post that? In my opinion, that makes it low-quality content, so worth a downvote.
disagree. again, we don’t even know if such a change would be beneficial.
also, more importantly, the post is entirely stupid.
suboptimal by what measure? became disadvantageous how? against what? last time i checked ve**rtebrates were still dominating. now even more than they did during the ages of dinosaurs.
evolution was too late to correct it… what? first of all, is it even a mistake to correct? where’s the evidence of that? second of all, did evolution stop? too late how? it’s complete bullshit, and if anything the original comment wasn’t harsh enough on it.
I’m not claiming that this change in how eyes work would be an improvement. I’m claiming that the following does not hold generally: “Doesn’t have adaptation X ⇒ adaptation X would not improve fitness.”
yeah but that’s not part of the original comment, not even by implication. the opposite is also not true so it doesn’t factor in at all. even though you’re not claiming it would be an improvement the original post clearly does and that’s what the top level comment is countering.
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.)
Not sure if all but at least 7. - 10. are extinct.
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.
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.
