Vision and Evolution (A Critique of Dawkins)

[Peebothuhlu]

I thought I already responded to that elsewhere, but its ok. First, keep in mind we're talking about how things change or evolve. Pointing to a species with brains and no eyes isn't useful unless you're using them as a predictive step in our evolution, for example, or tying it back in to evolution. What good is a species with no eyes, in a discussion about eyes lol. Clarify that for me a little more, so we're on the same page. For now my answer is that brains can do other things besides seeing. And as far as eyes with no brains, I would ask if you're using brains in a specific sense, or as a general description of whatever processes information? Are you talking about organisms with eyes whose visual information leads absolutely nowhere?

But I agree that Dawkins' video is meant for children, I believe they are Christimas lectures even lol; I've said previously that my statements shouldn't be controversial.

Well... you've been saying that you don't understand how the whole brain and eye thing can happen.

I've just been pointing out that critters can develope eyes with out neurons behind them (Really. The Boxjelly fish has eye clusters that are not connected to neurons at all. Jellyfish really do not have brains in even a rudimentary sense.)

Why does that particular jelly have eyes when no others do? Because pretty much all other jellys are a kind of passive 'Filter feeders'.
Boxjellys activly hunt prey. Their eyes drive their motion with no neurons in any shape of a brain that can be found.

As for critters that respond to visual stimulous with out using their eyes. That's something you don't seem to have considered at all either.

My question in regards to 'Blindness' is about sort of the reverse of your questioning path.

Why are there critters (Fish, amphibians, insects) who don't have eyes while other, sister species still do?

You do grok how atrophy can happen, right?

So... you're on board with critters changing over time. Cool.
You've underestanding of the rather vast times potentially involved (Which is not to say that morphological and other changes can't happen 'Quickly' for a rather loose definition of 'Quick'.) yes?

Though, again, I'd remind you that the theory doens't actually make 'Hard' predictions about where things develope.
That's even possibly one of its failings.

For example.

We might hypothesis that... should a totally new environment appear... That creatures will (As a species, not a single indivual) over time change and adapt to different parts/elements of said enviropnment.

BUT

Not specifically how each possible critter type might change into what ever niche and in what possible way.
Other than suggesting covergent requiremnts. If there's lots of spaces and vertical motion possible then flight might emerg. If there's lots or total water then hydrodynamic traits might emerg. etc. But not in which species or what change might or might not occur or when.

Similarly. Any environment on another planet will have critters that will have 'X' looking developments. Should the planet have a descent enough atmosphere then flight might be found in regards to some critters. Some critters will be hydrodynamically streamlined for swimming etc.

That you might have a giant shrimp that looks like an Orca however is the thing that'd be waaaaay outside the box for human experiance.

Cheers.

Not at work.

[John 6IX Breezy]

Well... you've been saying that you don't understand how the whole brain and eye thing can happen.

I've just been pointing out that critters can develope eyes with out neurons behind them (Really. The Boxjelly fish has eye clusters that are not connected to neurons at all. Jellyfish really do not have brains in even a rudimentary sense.)

Why does that particular jelly have eyes when no others do? Because pretty much all other jellys are a kind of passive 'Filter feeder'.
Boxjellys activly hunt prey.

My question in regards to 'Blindness' is about sort of the reverse of your questioning path.

Why are there critters (Fish, amphibians, insects) who don't have eyes while other, sister species still do?

You do grok how atrophy can happen, right?

Not at work.

Well, all I know about jellyfish is that they have what is called a neural net with no central nervous system. I wasn't aware they had eye clusters, although I imagine they had some kind of sensory input. So I'll have to take a closer look at what you're talking about.

The atrophy question is interesting because I don't generally have any issues with things atrophying or becoming vestigial, or losing their functions overtime. So if the reason why some fish have eyes and other don't is that those fish used to have eye but that function is now lost, then I have no quarrels there. Is that what you meant by atrophy?

Edit: Just saw you added more.

I'm generally not concerned with the timing. I'm more worried about whether or not something can happen, not how long it took to happen. But yes, I'm aware of the time. As to making hard predictions I agree that it doesn't, or isn't able to. However, we're not predicting the future with these questions, we're uncovering a past that already happened. Those steps are already in whatever order they are.

[Peebothuhlu]

Well, all I know about jellyfish is that they have what is called a neural net with no central nervous system. I wasn't aware they had eye clusters, although I imagine they had some kind of sensory input. So I'll have to take a closer look at what you're talking about.

The atrophy question is interesting because I don't generally have any issues with things atrophying or becoming vestigial, or losing their functions overtime. So if the reason why some fish have eyes and other don't is that those fish used to have eye but that function is now lost, then I have no quarrels there. Is that what you meant by atrophy?

Edit: Just saw you added more.

I'm generally not concerned with the timing. I'm more worried about whether or not something can happen, not how long it took to happen. But yes, I'm aware of the time.

As to making hard predictions I agree that it doesn't, or isn't able to. However, we're not predicting the future with these questions, we're uncovering a past that already happened. Those steps are already in whatever order they are.

Yes... Australian boxjellys have four eye clusters with which their motion is guided towards 'Prey'. Whether that's other fish... Or people swimming.

So... an eye system with out a brain attached.

You're wrong about predictions on one level, though.
On a broad brush scale you can make pedictions. Both backwards in time and looking off to other worlds/environments.
Looking back through geology hypothesis can be formed and fossils found to either falsify or bolster the hypothesis.
Hence finding Tiktaalik being a successful bolstering of the theory.

If there's a planet with liquid water (Or, technically any life bearing liquid) then you will have things that look like fish.
If the atmosphere is dense enough you'll have flying critters.

What those fish looking things willactually be? That we can't guess at, hence my comment about a crustacean shaped like an Orca.

Now.. about that critter which can discern things about its surroundings and react to such while not using the eyes that it has (Though it's still using its brain).

Cheers.

Not at work.

[GrandizerII]

Maybe it just so happens to be the case that "vision" is a bit of a loaded term. And it just so happens that eyes and brains aren't necessary for a "living" detection of, and reaction to, stimuli.

For humans, part of the definition for that word "vision" involves the perception of what you see, and we require the eyes for sensing and the brain for perceiving. For jellyfish and other such simple organisms, it's a different story. And for other organisms, other different stories. It's not so clear cut black or white, after all.

[John 6IX Breezy]

Yes... Australian boxjellys have four eye clusters with which their motion is guided towards 'Prey'. Whether that's other fish... Or people swimming.

So... an eye system with out a brain attached.

You're wrong about predictions on one level, though.
On a broad brush scale you can make pedictions. Both backwards in time and looking off to other worlds/environments.
Looking back through geology hypothesis can be formed and fossils found to either falsify or bolster the hypothesis.
Hence finding Tiktaalik being a successful bolstering of the theory.

If there's a planet with liquid water (Or, technically any life bearing liquid) then you will have things that look like fish.
If the atmosphere is dense enough you'll have flying critters.

What those fish looking things willactually be? That we can't guess at, hence my comment about a crustacean shaped like an Orca.

Now.. about that critter which can discern things about its surroundings and react to such while not using the eyes that it has (Though it's still using its brain).

Cheers.

Not at work.

Well the backwards in time predictions is what I'm saying or looking for. Which is why pointing at plants, for example, doesn't do much for the conversation unless we're predicting that there were plant-like ancestors in our evolutionary lineage; or predicting how plants can evolve eyes, if they ever do.

As to the jellyfish. I guess to summarize what I've said in the past, I'm not concerned with the specific components that organisms have or don't have; I'm not saying a brain is needed to survive or eyes to sense the environment. So again, we have to insert the jellyfish into a talk about evolution for my OP to apply. For example, how jelly fish evolved, or how they can evolve to something like our system.

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Maybe it just so happens to be the case that "vision" is a bit of a loaded term. And it just so happens that eyes and brains aren't necessary for a "living" detection of, and reaction to, stimuli.

For humans, part of the definition for that word "vision" involves the perception of what you see, and we require the eyes for sensing and the brain for perceiving. For jellyfish and other such simple organisms, it's a different story. And for other organisms, other different stories. It's not so clear cut black or white, after all.

Right, I know people don't intend it this way but it almost becomes strawman-ish to talk about other unrelated species. I can understand the argument they're trying to make, just not entirely how it applies. I'm comfortable sticking with the term vision because that is what I want to focus on, vision as it applies to humans. Dawkins' video is an account of how human (or human-like) eyes evolved. So staying within our evolutionary history, and our anatomy and physiology, helps solve issues of communication somewhat.

[Peebothuhlu]

Well the backwards in time predictions is what I'm saying or looking for. Which is why pointing at plants, for example, doesn't do much for the conversation unless we're predicting that there were plant-like ancestors in our evolutionary lineage; or predicting how plants can evolve eyes, if they ever do.

As to the jellyfish. I guess to summarize what I've said in the past, I'm not concerned with the specific components that organisms have or don't have; I'm not saying a brain is needed to survive or eyes to sense the environment. So again, we have to insert the jellyfish into a talk about evolution for my OP to apply. For example, how jelly fish evolved, or how they can evolve to something like our system.

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Right. So Tiktaalik then.

You have said you don't understand the whole eyes/brain thing.

I was just pointing to a critter that has eyes and no brain because for a while that seemd to be to biological things you were hooked up on.

So... as for how things came to be?






 I've found this to be erudite and entertaining.    

Cheers.

Not at work.

[John 6IX Breezy]

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Right. So Tiktaalik then.

You have said you don't understand the whole eyes/brain thing.

I was just pointing to a critter that has eyes and no brain because for a while that seemd to be to biological things you were hooked up on.

 I've found this to be erudite and entertaining.    

Cheers.

Not at work.

I think an issue in this thread has been that other's have slowly added things to what I'm saying to the point that even I myself have lost track of what I'm saying. Certain things have snowballed where someone else reads what someone else wrongly suggests I'm saying, and brings it up again. Then when I address it, it gives the appearance to someone else that that's what we're discussing and so forth. 

So if you read the OP again, you'll see that the jellyfish would be accounted for.

I'll watch the video.

[Abaddon_ire]

http://www.notjustatheory.com/

Ramen.

My bad, its "triumphantly" just a theory. Thanks.

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Gravity is "just a theory". Wanna go walk off your nearest cliff? After all, gravity is "just a theory". Should be a breeze to you.

Gravity isn't a theory lol. Its a natural phenomenon that different theories have tried to explain (i.e. general relativity?).

Right. So the Theory of Gravity is merely a theory. It would be as valid to propose a theory of space pixies pressing all of us down to the surface, right? After all, it's just a theory, right?

And if, as you claim, gravity is not a theory, why is there a theory of gravity? Are you claiming that the Theory of Gravity simply does not exist?

[John 6IX Breezy]

My bad, its "triumphantly" just a theory. Thanks.

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Gravity isn't a theory lol. Its a natural phenomenon that different theories have tried to explain (i.e. general relativity?).

Right. So the Theory of Gravity is merely a theory. It would be as valid to propose a theory of space pixies pressing all of us down to the surface, right? After all, it's just a theory, right?

And if, as you claim, gravity is not a theory, why is there a theory of gravity? Are you claiming that the Theory of Gravity simply does not exist?

A theory of space pixies wouldn't be as accurate as another theory of gravity (depending on the theory), but yes, they would both still be just theories. So their validity would differ, but not their composition as theories.

What do you mean by if "gravity is not a theory why would there be a theory of gravity?" I don't understand.

[The Grand Nudger]

Nobody has added a damned thing to your confusion but you. Remember, all of this is just you avoiding the fact that you were wrong, lol.

Yes, there actually are “plant-like” creatures in our lineage...you share a common ancestor with cucumbers. There are also creatures with no brains or eyes.