The Evolution of the EYE

Creationists always drag up the old 'Half an eye is useless and part of an eye is useless' ... 'as only a fully formed, fully functional eye could be of any benefit to any organism, then it "must' have been created in the formed state...'
- er ... by a creator right?
They seem to think it could not have evolved.
All I hear with that argument is the same old circular logic but so many are blind to it.
The thought that, if creationists can just come upon one thing, one particular organ or part of a living organism that they can describe as 'too complex' or 'only of any use when fully formed' then they surmise that they have made their argument and they imagine it is a strong argument at that!!
I must be missing something?

This film simplifies it for anyone who is wondering about the possible process by which an item like an eye could have evolved whilst at the same time, providing an advantage over the less evolved eye-bearers around at the time.
Discuss!

Category:

Science & Technology

Tags:

• evolution
• darwin
• natural
• selection
• creationist
• creationism
• religion
• christian
• atheism

[cmpresents]

Ok again, in big steps. You first need a brain, stop. Just imagine the complexity of this brain to know how to evolve. We have to stop right there, this just doesn't happen. Is like telling that you have a cell, that with enough time can become all these animals and then a human too. And that this happaned by accident. Never.

[HitMeWithIt]

@cmpresents Nothing you just said actually makes any kind of logical sense. what exactly are you trying to say?

Is your argument one of 'It is far too complex for our brains to even comprehend therefore...we must stop trying to comprehend..'?

And if this is what you are saying then how can you possibly believe in a GOD?

Surely I don't have to point out the obnvious flaw here. OK I will: A GOD is utterly and totally complex and incomprehensible!

[haz020190]

@cmpresents "Just imagine the complexity of this brain to know how to evolve"

the brain doesnt decide how or know how to evolve you moron.

and you dont neccesarily need a brain (if u have eyes you need a basic nervous system minimum).

[haz020190]

@haz020190 since the clusters are linked directly to the eyes you could also suggest that they are the ancestors of more complex optic nerves, and since we have 1 optic nerve per eye as is the same with these clusters, then that may hold weight too.

If you are generally wanting to learn about this, there are plenty of free papers online, you may have to google a word every few lines but if ur willing to push through that then i suggest doing that.

[haz020190]

@pussylumpessru I think in the scheme of things those clusters would be the ancestor of the visual cortex, but in terms of complexity, its like comparing a computer processor with a single transistor. billions of cells vs a handfull of cells. so no i would say they dont have a visual cortex. And in the simple jellyfish, where they dont even have the nerve clusters. they most certainly dont. But its good that we can see a possible first step towards a visual cortex, all be it incredibly simple

[pussylumpessru]

@haz020190 if they have no brain, do they have a visual cortex? Would those clusters of nerves act as a visual cortex?

[haz020190]

@pussylumpessru (cont) However if the information is as simple as 'do' or 'dont' swim, or 'light' or 'dark'. then no processing is required and so the brain is not needed.

Box jellies have more complex eyes with retina and lenses, and yet they still only have primitive clusters of cells to process information. these clusters are essentially basic circuits (of which our brains contain billions), of nerves connecting to each other. No new features are used, just an added nerve here or there.

[haz020190]

@haz020190 (cont) " the brain must too, because the nerves exist as a passage to the brain, right?"

I think you are looking at ths from a human perspective, yes most of our nerve pathways operate via the brain.

But if we look at muscles, they respond to electrical nerve pulses. Now in humans the nerve pulses the muscles receive are essentially the same as those the brain receives, only they have been processed and filtered for useful information.

(cont)

[haz020190]

@pussylumpessru its understandable that this concept is difficult.

But if we look at jellyfish, which have no brains, and nerves which arent particularly specialised. The signal taken from the eyes is sent to the muscles sometimes directly and (at the height of jellyfish complexity) via some simple processing cells. the only signal or 'code' that is being transmitted here is either 'keep swimming this way' or 'dont swim this way' and so doesnt take much processing power.

(cont)

[pussylumpessru]

@haz020190 I don't get that... all I know is that for eyes, there must be an optic nerve, or something to transmit the light somewhere...And then if the optic nerves exist, the brain must too, because the nerves exist as a passage to the brain, right? So..I see that as a dependency through out all of those structures in the system of sight, so i don't get how only one of those pieces could do the job..

[haz020190]

@pussylumpessru sorry ill have to go find what i said lol. Also... I dont see what your question is?

Also on a quick note. the brain is not necessary. Many jellyfish have simple eyes and no brains.

[pussylumpessru]

@haz020190 I'm really sorry for this late reply. This is replying to your response of the optic nerve during eye evolution. But, I don't understand: Those early eye evolving organisms with "simple" brains like worms, as you said..already have a pair of simple optic nerves.. therefore, they would have needed to pass the first stage of being sensory nerves, as you said.