OBSTACLES IN EVOLUTION PT. 4

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ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
OBSTACLES IN EVOLUTION PT. 4

As mentioned previously, the gradual evolution of photoreceptors, from a few cells to an entire eye, is simplistic to the point of irrelevance. Vision almost certainly doesn’t occur in the retina, but in the brain. Here are several other obstacles to the evolution of the eyes, focused on motion perception.

1. Motion Blur – Vision is in constant motion. Visual objects move, your eyes move, your head moves, your torso moves, your whole body moves. Move a camera half as much, and without high fps, you’ll see almost constant blur. Our eyes solves this problem through a suppression mechanism, keeping vision clear. This mechanism essentially blocks vision while our eyes shift. It also uses the vestibular system to stabilize the eyes as your head moves. Obviously, without this suppression and stabilization, you can’t see what you’re doing when franticly escaping danger.

2. External Motion – If there are two dots in front of you, and you stare at the left one which is stationary while the right one moves, the retinal image produced is identical to a scenario in which right one is stationary and your eyes track the left one as it moves. In other words, you need a system outside the retina, which can detect if the objects are moving, or your eyes are moving. One simple method is to use information from the muscles around the eyes. Without that information you wouldn’t know if a predator is coming towards you, or you are coming towards the predator.

3. Motion in Retina – Both of the above examples assume we can detect motion already. However, photoreceptors in the retina cannot detect motion. The idea that the retina can gradually increase in size, slowly cupping, until it forms a compact eye, and ta-da! you have vision, is fundamentally flawed. You need a network dedicated to the perception of motion. Such networks can be found in area V1 and MT of the brain. The system is complicated, but to simplify, imagine there are two photoreceptors, in different locations of the retina. As an image travels across the retina, it activates one receptor first, and then the next. Both of these receptors sends information to a third neuron, that fires when both receptors are activated at the same time. Obviously they can’t activate at the same time if something is moving. So these receptors have a delay system. Depending on how long the delay is, an object traveling at a specific speed, activates one receptor, then the delayed signal reaches the third neuron by the time the object activates the second receptor. Notice that these neurons can only detect objects moving at a specific speed and direction. If the object is moving faster or slower, it won’t be detected. Without an entire system of these neurons, dedicated to motion perception, an animal cannot detect motion.

4. In case you don’t know, damage to the MT portion of the brain leaves people motion blind. They see the world as independent still images. To show how problematic it is to have vision without this system, consider that people with motion blindness can’t tell which direction a car is moving or how fast. If they’re not careful they can easily be killed. Many people with motion blindness need to compensate with practice, by focusing on the sound.

I only have two questions: How did our ancestors survive before the perception of motion evolved; and how did the perception of motion evolve in the first place?

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Many of you like to tell me I don't know how evolution works. That's a beautiful statement, because the easiest people to correct, and the easiest questions to answer, are those asked by people who don't know how something works. Much harder, are the questions asked by people who do know how the thing works. So don't just tell me I don't know how evolution works, show me by answering the question. Also, if you don't know the answer, don't complain to me about it. Go find out, or move on with your life.

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CyberLN's picture
John,

John,

In another of your OPs on this subject, you wrote, “I am interested in the answer. I just don't think you guys have any. I think you guys blindly follow evolution without actually knowing anything about it. I think most atheists just read a Dawkins book and pat themselves on the back. None of this matters however, because what I think doesn't stop you from giving me an answer. The "gotcha" doesn't come when you answer. The "gotcha" comes when you don't lol.”

Well, I actually trust that these professionals aren’t full of shit. If I am curious about a particular item or would like an overview, I would read their publications. I don’t have to have all the answers in my pockets to understand they are available from trustworthy sources.

So you can continue to beat this rather dead horse, seemingly getting off on the ‘failure’ of anyone identified as atheist, but not an evolutionary biologist, to give you what you might dream as the correct answers.

Personally, I have grown to find this series of Your OPs rather amusing.

https://en.m.wikipedia.org/wiki/Level_of_support_for_evolution

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
"I don’t have to have all the

If the answers are available from trustworthy sources, could you please find those publications and share them? Thanks.

Sheldon's picture
"If the answers are available

"If the answers are available from trustworthy sources, could you please find them and share them? Thanks."

I did this already and unsurprisingly you completely dismissed it as irrelevant. However here is another link for you to ignore.

https://www.pbs.org/wgbh/evolution/library/01/1/l_011_01.html

It's a scientific fact, with scientific consensus throughout I'd need a reason to doubt that, and superstitious flimflam about talking snakes and magic apples simply is a laughable reason to deny scientific facts. As I have pointed out you are cherry picking parts of science to disagree with based on your religious beliefs, whilst this is your choice it's hilarious for you to try and pretend your objections have any scientific validity. If you want the answers then do the research, this is an atheist forum, and so evolution is largely irrelevant. If evolution were properly falsified tomorrow I'd still be an atheist, and creationism would still be superstitious nonsense without a shred of evidence to support it.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
What is with people repeating

What is with people repeating the same thing over and over?

I'm more than aware how the narrative goes. Even if I wasn't, saying it once suffices. This is a critique of that narrative. Adjust your answers accordingly.

Sheldon's picture
"What is with people

"What is with people repeating the same thing over and over?"

What is it with people asking the same question over and over, while ignoring the answer?

The truth is always the correct answer, so if you dishonestly ignore it and keep repeating your question it's axiomatic you'll get the same answer which is as true now as when you first asked.
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"Sun, 10/22/2017 - 11:16
John 6IX Breezy
If the answers are available from trustworthy sources, could you please find those publications and share them? Thanks."

I notice you are ignoring yet another answer to your question, right on cue...so here is the link you asked for.

https://www.pbs.org/wgbh/evolution/library/01/1/l_011_01.html

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
Your link: "Here's how some

Your link: "Here's how some scientists think some eyes may have evolved: The simple light-sensitive spot on the skin of some ancestral creature gave it some tiny survival advantage, perhaps allowing it to evade a predator. Random changes then created a depression in the light-sensitive patch, a deepening pit that made "vision" a little sharper. At the same time, the pit's opening gradually narrowed, so light entered through a small aperture, like a pinhole camera."

Great. Wonderful. Beautiful. In my OP I mentioned this narrative is simplistic to the point of irrelevance. I then gave you a few examples why. Can you harmonized the points I presented, and your PBS link?

Sheldon's picture
"Great. Wonderful. Beautiful.

"Great. Wonderful. Beautiful. In my OP I mentioned this narrative is simplistic to the point of irrelevance. I then gave you a few examples why."

You're not qualified to make such objections, if you were you could publish them and reverse or amend the current scientific theory of evolution. Then collect your Nobel prize and become famous. I've encountered this kind of mendacious creationist bluster before, it's nothing new, and it is of course nonsense. To falsify a scientific theory would be a paradigm shifting event, and it doesn't happen in internet chat rooms. You can ignore these facts all you want, but I'll just keep pointing them out, and you'll keep sulking.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
"You're not qualified to make

Lol you're a broken record at this point. I would venture to say the opposite: If you can answer my question, that would win you the Nobel Prize.

Sheldon's picture
"Haha you're a broken record

"Haha you're a broken record at this point."

Irony overload...

"I would venture to say the opposite: If you can answer my question, that would win you the Nobel Prize."

And I'd repeat your grasp of the scientific method is execrable, I hope your university education is free, though I suspect you're still being over charged.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
Let's play a little game. It

Let's play a little game. It's called "what was my OP's question?" Can you find it? Paste it below to receive points.

Hint: There are two of them.

Sheldon's picture
Lets not play games. Lets

Lets not play games. Lets stick to the forum topic and stop pretending you have any valid objections to scientific facts you don't even understand.

Hint: This is an atheist forum, not a science forum.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
-5 points for not finding the

-5 points for not finding the questions. I'm feeling good today, so I'll give you another chance. Can you you find the questions?

Hint 2: They're set apart by a paragraph break.
Hint 3: They have a question mark.
Hint 4: They're in the OP.

Sheldon's picture
" In my OP I mentioned this

" In my OP I mentioned this narrative is simplistic to the point of irrelevance."

You might want to Google, then try to understand the significance of, Occam's razor.

MCDennis's picture
Four times the nonsense from

Four times the nonsense from this idiot. I gave up reading his posts a long time ago

Sheldon's picture
I don't blame you, though

I don't blame you, though ironically I'm sure he thinks he's proved something when people stop responding to his tedious duplicity.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
I'm not proving, I'm

I'm not proving, I'm questioning. Know the difference.

Sheldon's picture
"I'm not proving, I'm

"I'm not proving, I'm questioning. Know the difference."

You're speculating wildly, nothing more. The facts remain the facts, and species evolution remains an established scientific fact beyond any reasonable doubt. Creationism remains nothing more than superstition.

Kataclismic's picture
When you ask a question which

When you ask a question which you are convinced you already know the answer to, that doesn't actually qualify as asking anything. I tried to make this point earlier but you didn't pay any attention. If you were actually interested in learning you would be reading, not posting.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
I just don't see the

I just don't see the relevance. Whether I know or don't know the answer, whether I'm studying or not studying, the question is still being addressed to the audience.

Alex Howe's picture
Saying that something is

Saying that something is simplistic to the point of irrelevance is great and all but that doesn’t actually prove anything. It is possible that the answer to something may be simple, evolution would not work unless things were simple as the changes are gradual and small, the idea of gradual change being “simplistic to the point of irrelevance” is ignorant and false

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
What I called simplistic is

What I called simplistic is the scripted explanation of how the eye evolved. By that I mean it doesn't take into account all the components that are needed for the eye to function. Motion perception is one such component.

Sheldon's picture
"What I called simplistic is

"What I called simplistic is the scripted explanation of how the eye evolved. By that I mean it doesn't take into account all the components that are needed for the eye to function. Motion perception is one such component."

Quelle surprise, every time the answers are given you don't like them. I'm sure your dismissal has shook the scientific world to it's very core. I can see Darwin's statue being removed form the Natural History museum in London now, and yours being unveiled. this is hilarious...

Jared Alesi's picture
So, the idea that their

So, the idea that their eyesight was terrible doesn't matter. Even if their eyes were useless, that's all: useless. The point of natural selection is not that only beneficial changes are passed on, but that any change which does not kill the organism before it mates can be passed on. So the eye is crap until it's not. Then when it works with some degree of accuracy and helps the organism survive, that model of the eye has a much greater chance of continuing its success. Maybe the next mutation screws it up. Why do you think some animals don't rely on sight? Perhaps the next mutation is even better. Hence the reason every animal has uniquely formed eyes, each with varying levels of perceptive ability.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
I think its little more

I think its little more consequential than having crappy eyes. A non-functioning eye can be ignored, but a half-working eye can't. If the crappy eye is providing crappy information, the animal will produce crappy behaviors. Animals can't just ignore or inhibit one of their senses, if the sense is sending information into the brain, the brain will process it.

For example, if I ask you to close your eyes and balance yourself on a beam, you'll do it just fine once you get the hang of it. But if I ask you to open your eyes, and I move the walls forwards and backwards, the information from the eyes automatically affects your balance. You'll sway back and forth with the wall, and fall. No one touched no, no one moved the beam. But the information from the visual system was enough to mess up your balance.

A half-functioning eye can get you killed.

Jared Alesi's picture
This isn't quite the same.

This isn't quite the same. While it's true that crappy info can get you killed, the primitive species with barely working eyes doesn't know it's crappy. If an organism only sees blurry color, no motion, and faint brightness registers, it may do fine, terrible, or the same. The primary difference here is that this organism didn't suddenly change its state of vision like in your scenario. It's always had crap vision. It learns to use that vision how it can, or ignore it. If all I ever see is varying shades of green in amorphous waves, I'll learn to function. If a later descendent can see vague outlines of figures, hooray for progress. If a later one 'sees' things that aren't correct, it'll die. But mutation is random and unbiased. There might be a thousand failures before another success. Eventually (four billion years of trial and error seems sufficient to me), high functioning eyes that can focus well and perceive useful bits of the electromagnetic spectrum may arise.

Jared Alesi's picture
For example, a blind man

For example, a blind man doesn't know color exists if you don't tell him. He'll use his other senses to get around. Most extreme-depth sea creatures are at least partially blind. They're doing fine, near as I can tell. Moles are mostly visually impaired, so they use other senses. Their partial vision doesn't distract them and cause them to walk around like drunkards.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
Well the main goal with this

Just be aware you can't say things like "learn to function" without invoking biology. You can't learn to function unless you have a system capable of learning to function. For example, we have such a system. Thus if I put prism glasses on that shift the world in either direction, I'll eventually compensate and learn to function under the new input. If the animal doesn't have something similar, it doesn't matter if it knows or doesn't know it has a half-functioning eye, because the environment won't care

I have no problem with what you're saying overall. But I don't want you to assume there aren't similar problems there too. By saying you can just use the other senses you're assuming they have them. Moles may have them, but did their ancestors? Was the ear fully developed while the eye was developing? It was probably underdeveloped too, and encountering it's own thread of problems it would have needed vision to solve.

Sheldon's picture
"A non-functioning eye can be

"A non-functioning eye can be ignored, but a half-working eye can't."

It still works, and is advantageous, half an eye is better under most circumstances than a quarter of an eye.. a few light sensitive cells can hell detect predators by sensing shadow in the right environment that's the different between surviving to pass on your DNA and becoming a hot lunch. Also these facts are well established in evolutionary science.

"A half-functioning eye can get you killed."

Yet a few light sensitive cells can save it, go figure, it's almost as if the environment is a determining factor, and advantageous attributes that help animals survive are passed on, step by step by step...

http://t1.gstatic.com/images?q=tbn:ANd9GcRVt_p4GX2oEMhcQYZkZwoN4pAjhdeC3...

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
What do you mean by half an

What do you mean by half an eye? A few light sensitive cells may detect shadows, but they cannot detect predators or food or anything else. That requires a separate system capable of making those distinctions. A shadow is a shadow regardless of its origin. Detection also doesn't equate to behavior. That requires another system that tells the animal if it ought to move towards the dark or away from it.

Sheldon's picture
"What do you mean by half an

"What do you mean by half an eye?"

It was your expression not mine. Though you meant to try and reverse engineer the completed eye to try and pretend only a complete eye is of any use, but scientists know this is simply not the case, and every stage of evolution of the eye can be seen on animals right now. from a small collection of light sensitive cells to the complete eye and every stage in between.

" A few light sensitive cells may detect shadows, but they cannot detect predators. Detection also doesn't equate to behavior. That requires another system that tells the animal if it ought to move towards the dark or away from it

Think again..."The earliest exhibits date from the Ediacaran period, around 550 million years ago. Sandstone slabs show the fossilised traces of small worm-like animals burrowing on the sea floor. The directions of their tracks suggest that they had simple photoreceptor cells containing molecules sensitive to light, which could detect the shadow of another animal passing by or guide them to brightly lit areas where their microbial food sources were more likely to be found. "

https://www.ft.com/content/ca718ed4-4303-11e6-9b66-0712b3873ae1?mhq5j=e7

So animals that have that ability have on increased chance of avoiding a predator to those that don't, and that means they are more likely to pass on that ability, that is survival of the fittest.

https://www.pbs.org/wgbh/evolution/library/01/1/l_011_01.html

https://www.sciencedaily.com/releases/2016/06/160620140929.htm

http://learn.genetics.utah.edu/content/selection/eye/

http://webvision.med.utah.edu/2014/07/evolution-of-sight-in-the-animal-k...

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