[Alberto]

I am wondering whether this animal has sight:


To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.


Do you know if this animal evolved without any sight whatsoever namely without any possibility of perceiving luminous signals/waves?

If it is sighted, can you name an animal that is naturally without sight?

[zibber]

	Originally Posted by Alberto To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	If it is sighted, can you name an animal that is naturally without sight?

Ack. I was gonna say Stevie Wonder.

[Alberto]

	Originally Posted by zibber To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	Ack. I was gonna say Stevie Wonder.

by «naturally» I mean it is "natural" for its species to be without sight.
Is that animal such? And if not, can anyone name an animal "naturally" without any sight whatsoever?

[Elena]

This fish comes in an eyeless form of variation.
To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

[Alberto]

	Originally Posted by Elena To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	This fish comes in an eyeless form of variation. To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

Ok, so if I say that in nature there exist species (at least one) whose instances are born and die without ever knowing what light is, I am correct?
Or am I wrong?

[Elena]

I am no biologist, but using an eyeless fish like that for an example, then yes a creature can be born and die with out seeing light. Check out a list of cave living creatures, bet some are blind too.

---------- Post added 06-18-2012 at 05:41 PM ----------

A list of some more.
To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

[Alberto]

	Originally Posted by Elena To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	I am no biologist, but using an eyeless fish like that for an example, then yes a creature can be born and die with out seeing light. Check out a list of cave living creatures, bet some are blind too.

Ok so we have animals who are sightless by species, since ever - or at least, to date, evolution did not provide them with sight.

I make the following hypothesis: since we have found at least one species in nature that is sightless, if I imagine that also a mammal like the Human could have been sightless, am I making an hypothesis that is totally irrational, or am I saying something that, at least in theory, could have been our fate also (and not uniquely that of that species)?

Is such an hypothesis (that the human species could also have been sightless) totally irrational or is it an hypothesis that belongs to the set of the possible and rational hypothesis, though not realized in practice?
Or is it fairy tales?

I don't know, but I would like to know.

[Imperator]

To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

[Alberto]

	Originally Posted by Imperator To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

Ok we even have more than one species that is totally sightless.

Could this, at least in theory, have been also the fate of the human species since it was already of other species? Is this hypothesis rational or does it belong to the totally irrational like say fairy tales are?

[Imperator]

Originally Posted by Alberto To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

Ok so we have animals who are sightless by species, since ever - or at least, to date, evolution did not provide them with sight. I make the following hypothesis: since we have found at least one species in nature that is sightless, if I imagine that also a mammal like the Human could have been sightless, am I making an hypothesis that is totally irrational, or am I saying something that, at least in theory, could have been our fate also (and not uniquely that of that species)? Is such an hypothesis (that the human species could also have been sightless) totally irrational or is it an hypothesis that belongs to the set of the possible and rational hypothesis, though not realized in practice? Or is it fairy tales? I don't know, but I would like to know.

I'm not a biologist, but I would expect for a homo species to have developed without sight, the situation of their development would have to be similar to other creatures that don't have eyes or use sight, eg, deep ocean or completely dark caves.

Since we live under the sun, I'm guessing the chances of a homo variant being sightless to be fairly slim. If there was one such species, it's clearly already dead.

[Elena]

Originally Posted by Alberto To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

Ok so we have animals who are sightless by species, since ever - or at least, to date, evolution did not provide them with sight. I make the following hypothesis: since we have found at least one species in nature that is sightless, if I imagine that also a mammal like the Human could have been sightless, am I making an hypothesis that is totally irrational, or am I saying something that, at least in theory, could have been our fate also (and not uniquely that of that species)? Is such an hypothesis (that the human species could also have been sightless) totally irrational or is it an hypothesis that belongs to the set of the possible and rational hypothesis, though not realized in practice? Or is it fairy tales? I don't know, but I would like to know.

Are you saying that the fish did not evolve to be blind? I certainly think it evolved, as did other cave creatures to be naturally blind. Some 'see' light with sensors on their skin. If humans suddenly needed to live in a black dark world they would either die, because no food, or slowly get blind and evolve to eat tiny bits of food. Though we are too big for that.

[Alberto]

Originally Posted by Imperator To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

I'm not a biologist, but I would expect for a homo species to have developed without sight, the situation of their development would have to be similar to other creatures that don't have eyes or use sight, eg, deep ocean or completely dark caves. Since we live under the sun, I'm guessing the chances of a homo variant being sightless to be fairly slim. If there was one such species, it's clearly already dead.

Ok but we have species that live under the same sun and yet are sightless and nonetheless survived till today.
Yes, we have them.
No we haven't them.

Which?

[Imperator]

	Originally Posted by Alberto To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	Ok we even have more than one species that is totally sightless.

There are probably quite a few in the deep ocean.

	Could this, at least in theory, have been also the fate of the human species since it was already of other species? Is this hypothesis rational or does it belong to the totally irrational like say fairy tales are?

It's not rational in that the circumstances for human development and sightless species development are incompatible.

It's rational in that if humans developed in the deepest, darkest parts of the ocean, it's conceivable we wouldn't have developed eyes or sight.

[Elena]

	Originally Posted by Alberto To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	Ok but we have species that live under the same sun and yet are sightless and nonetheless survived till today.

They live under the sun. But some live out of reach of the sun rays. Deep in caves like that fish, underground like the star nose mole or under water like other things.

[Imperator]

	Originally Posted by Alberto To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	Ok but we have species that live under the same sun and yet are sightless and nonetheless survived till today.

We do?

So far it looks like everyone's been posting species that live in areas totally devoid of light. Caves and deep ocean species.

Besides which, there are other factors to consider in terms of how and why a species survives. I'm pretty sure it doesn't work like a one-shot thing.

Flightless birds may survive either because they've developed something else (which made flight redundant) or because they just don't have any natural predators.

[Alberto]

	Originally Posted by Imperator To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	It's rational in that if humans developed in the deepest, darkest parts of the ocean, it's conceivable we wouldn't have developed eyes or sight.

Ok so that could have been a possibility.

Though we cannot still rule out there are animals living in caves and yet exposed to some light who none the less developed no sight. Maybe other may come up with instances.

However, can you name a mammal, or an animal that lives under the sun, that is blind or whose sight is really very short (say a scope of a few meters or a dozen of meters?).

---------- Post added 06-18-2012 at 06:56 PM ----------

I shall wait a few hours for more sightless animals living under the sun or in moderately lighted areas or that have a nearly non existant sight - if any.

[Imperator]

I take it you've put this in here because you're going to (eventually) argue that evolution and the development of life on Earth could not have happened without a divine hand in play, in whatever form you wish to present such an argument.

I'll hazard a guess and say you're focusing on sight because you've got some Discovery Institute garbage you want us to look at.

I'd appreciate if you just get to that point, and put forward your claim, its evidence, and your line of thought, so we can discuss something of substance and stop dancing and playing games.

[Alberto]

	Originally Posted by Imperator To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	I take it you've put this in here because you're going to (eventually) argue that evolution and the development of life on Earth could not have happened without a divine hand in play

No.
I am all with Charles Darwin.

Can anyone answer without bias to simple questions?

---------- Post added 06-18-2012 at 07:05 PM ----------

	Originally Posted by Imperator To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	I'll hazard a guess and say you're focusing on sight because you've got some Discovery Institute garbage you want us to look at.

Nope, None.
You made a second assumption - wrong.

I am asking simple questions.

---------- Post added 06-18-2012 at 07:05 PM ----------

Dunno, for instance maybe among these mammals there are totally blind ones or instances that are so weakly sighted to be considered fundamentally blind?


To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
)

[Imperator]

You've been given lists of animals without sight.

I don't know of any animals that are sightless and live on the surface in the daytime.

Bats and various nocturnal creatures probably have different types of eyes and sight than daytime creatures, better suited for moderate or low-level light.

I've heard Bald eagles basically have binocular vision, able to see up to several hundred yards away (from above).

I've also heard earthworms have no eyes, but can still detect light.

What's your point?

[Kisai]

	Is such an hypothesis (that the human species could also have been sightless) totally irrational or is it an hypothesis that belongs to the set of the possible and rational hypothesis, though not realized in practice? Or is it fairy tales?

Its difficult to say, like postulating a spherical cow. By the time that you solve all the problems that you have to in keeping such an animal alive, you've modified its DNA so much that it would no longer be considered in the same genus.

Humans are basically upright primates that developed in tropical climes. We have large brains and wide vision because we stand upright (heat dispersion and height, respectively). If we had developed in a lightless environment, there would have been less heat, so why stand upright? Then you'd have to have a lightless environment where primates would do well in, and underground isn't where they excel in, hence the lack of subterranean primates.

Maybe you're asking, if humans today were suddenly plunged into darkness, or into underground conditions, would they develop traits that were advantageous to lightless dwelling? If their survival depended on it, yes. What exactly, we don't know. Would they lose their sight? I don't know.

[Tocsin]

As people have already pointed out, there are numerous animals which have evolved from sighted to sightless, where sight presents no benefit - as in the absence of light.

If you are going to attempt to use this as a refutation of evolution, you might want to take a gander at this first:


To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

By Christopher Hitchens

...the likelihood that the post-ocular blindness of underground salamanders is another aspect of evolution by natural selection seems, when you think about it at all, so overwhelmingly probable as to constitute a near certainty. I wrote to professor Richard Dawkins to ask if I had stumbled on the outlines of a point, and he replied as follows:   Vestigial eyes, for example, are clear evidence that these cave salamanders must have had ancestors who were different from them—had eyes, in this case. That is evolution. Why on earth would God create a salamander with vestiges of eyes? If he wanted to create blind salamanders, why not just create blind salamanders? Why give them dummy eyes that don't work and that look as though they were inherited from sighted ancestors? Maybe your point is a little different from this, in which case I don't think I have seen it written down before.

[Alberto]

	Originally Posted by Kisai To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	Its difficult to say (...). Maybe you're asking, if humans today were suddenly plunged into darkness, or into underground conditions, would they develop traits that were advantageous to lightless dwelling? If their survival depended on it, yes. What exactly, we don't know. Would they lose their sight? I don't know.

Thank you for your biasless answer. Yes, that we might have been inhabiting the deep ocean or the underground is a possibility perhaps.
Do you think it would have been possibile? I know this is theory, I am just wodnering whether it is say an educated hypothesis in your/other's judgment or a totally irrational one.

I am just wondering if making the hypotesis the human mammal could have also been sightless is an hypothesis that could have occurred (slim chances, but could have been) or if it is something totally irrational that cannot even be postulated although a few species are totally blind and perhaps (but I await more competent answers) a few mammals are nearly blind (moles?)

---------- Post added 06-18-2012 at 07:17 PM ----------

	Originally Posted by Tocsin To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	If you are attempting to use this as a refutation of evolution, you might want to take a gander at this first:

I already answered this point - don't speculate. I am just asking simple questions.
As said, I am all with Charles Darwin and I consider creationism ridiculous.

[Elena]

You were given an example in my link of a mole which is fully blind, if you bothered to look. Moles, hedgehogs, hipo's and rhino's are known for poor eye sight. You can not say 'nearly blind' really. As someone said, humans appear nearly blind if against birds of prey with their superior vision.

[Alberto]

	Originally Posted by Elena To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	You were given an example in my link of a mole which is fully blind, if you bothered to look.

I did. I am just awaiting for more opinions and a few further confirmations.
Do you think a mole is a mammal and it is blind?
If so, have we some chances also human could have been, or is this hypothesis not even to be postulated so irrational it is?

I notice a few among you look nervous? Why? Relax. I am just asking simple questions as an ignorant person like me should do.

[Imperator]

	Originally Posted by Alberto To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	I am just wondering if making the hypotesis the human mammal could have also been sightless is an hypothesis that could have occurred (slim chances, but could have been) or if it is something totally irrational that cannot even be postulated although a few species are totally blind and perhaps (but I await more competent answers) a few mammals are nearly blind (moles?)

Didn't he answer this?
By the time you deal with all the factors to make sightless humans survive in a low-light environment, the DNA has been altered to the point where they're not the same species anymore.

Are you asking if humans as they are now, living in daytime conditions, on the surface, with great need for sight, could have developed without sight and survived?

Or are you asking if the hypothesis that humans as they are now could have survived without sight is even plausible?