Inverted retina, bad design or brilliant?

[T'ai Chi]

http://www.uncommondescent.com/intelligent-design/another-icon-of-bad-design-bites-the-dust/

Very interesting.

[TobiasTheViking]

in what way?

[ImaginalDisc]

in what way?

In that it's full of babble that supports Tai'Chi's preconceived notions that he is too cowardly to even express, lest he be called on them.

[Tanstaafl]

Here we go again.

[Dr Adequate]

So if the inverted retina of mammals is a good design --- does that mean that the uninverted retina of octopods is a bad design?

Incidentally, what is so "brilliant" about having a blind spot?

[Dr Adequate]

in what way? It's a fascinating insight into the bovine stupidity of creationists.

[Tanstaafl]

Incidentally, what is so "brilliant" about having a blind spot?

It gives god an opportunity to show off his visual processing algorithms.

[Myriad]

Yeah, who knew? The layer of cells through which light must pass to reach the photoreceptors in the human retina isn't opaque, as scientists wrongly believe! It's ingeniously designed to allow light to pass through!

It turns out we can see after all, despite what those silly "naturalists" and "Darwiniacs" claim!

Another Creationist straw man has been soundly defeated by Creationists! Huzzah!

(Note to those suffering from detached retinas: you still risk severe visual impairment or blindness. God apologizes; it's just the cost of such ingenious design.)

Respectfully,
Myriad

[Dragonrock]

http://www.uncommondescent.com/intelligent-design/another-icon-of-bad-design-bites-the-dust/

Very interesting.


Not really, it's just someone trying to justify their fantasy by twisting reality. Pretty much like all of ID.

[Wat Tyler]

...it's neither of the above - it's a good evidentiary example of how evolution is a non-directed process.

ETA: And one that occurs by the cumulative effect of small, random changes over time.

[fuelair]

Here we go again.
Off down the road again.

[Mercutio]

Dembski's source article speaks of "lots of light reflecting in synaptic and nerve layers, but with regular patterns of empty holes with no scattering"; within the holes (actually, Müller cells), there is excellent transmission of light (with a funnel-shaped deally to increase the amount of light collected). They conservatively report that "the müller cells can capture and transmit as much light as possible" (that is, given that the retina is back-to-front, this organization allows light through the maze of nerve cells and blood vessels. Dembski, though, crows that "now we find inside the eye optic fibers that transmit 100% through the layers of “bad” stuff in front of the cones and rods." Either he is carefully phrasing it so that he is speaking only of the transmission through the Müller cells--and thus his comment omits any admission that there is, in fact, loss of information through the synaptic and nerve layer scattering, or he simply misunderstands his source article.

The source article is far more interesting than Dembski's.

The most interesting thing on the Dembski page itself is this (http://www.uncommondescent.com/darwinalia/panda-monium.swf). I must say, though, I don't quite understand the point of its presence there.

[Gord_in_Toronto]

Dembski's source article speaks of "lots of light reflecting in synaptic and nerve layers, but with regular patterns of empty holes with no scattering"; within the holes (actually, Müller cells), there is excellent transmission of light (with a funnel-shaped deally to increase the amount of light collected). They conservatively report that "the müller cells can capture and transmit as much light as possible" (that is, given that the retina is back-to-front, this organization allows light through the maze of nerve cells and blood vessels. Dembski, though, crows that "now we find inside the eye optic fibers that transmit 100% through the layers of “bad” stuff in front of the cones and rods." Either he is carefully phrasing it so that he is speaking only of the transmission through the Müller cells--and thus his comment omits any admission that there is, in fact, loss of information through the synaptic and nerve layer scattering, or he simply misunderstands his source article.

The source article is far more interesting than Dembski's.

The most interesting thing on the Dembski page itself is this (http://www.uncommondescent.com/darwinalia/panda-monium.swf). I must say, though, I don't quite understand the point of its presence there.

You don't suppose that the phrase "the müller cells can capture and transmit as much light as possible" means as much as possible given the screwy backwards "design" do you? ;)

[CapelDodger]

So if the inverted retina of mammals is a good design --- does that mean that the uninverted retina of octopods is a bad design?

You beat me to it :) .

[CapelDodger]

Something I find interesting is the way that contrarian cultists of widely varying natures become fixated on ever narrower arguments, as if victory on this one specific point will turn around the whole war. Their resources become massively committed - Dembski is a pretty massive resource, and boy is he committed - while the mainstream bats their best efforts away without pausing. For climate denialists it's the Mann et al climate recounstruction, for 9/11'ists it's what chunks of landing-gear are hurled right through the building, for creationists it's the eye - which Darwin foresaw, sharp chap that he was.

It's a sign of defeat. They're just not making any headway. It must be terribly frustrating for them. I like to think so, anyway.

[Wowbagger]

The most interesting thing on the Dembski page itself is this (http://www.uncommondescent.com/darwinalia/panda-monium.swf). I must say, though, I don't quite understand the point of its presence there.
The whole point is at the very end, when an announcer says "No valid arguments were harmed in the making of this game." Get it, now?!

[Mojo]

Incidentally, what is so "brilliant" about having a blind spot?


It's well handy if there's stuff you don't want to see.

[Wowbagger]

Incidentally, it doesn't matter if we humans think that a design is "good" or not: for that is merely a subjective judgment.
What matters most is the empirical evidence, and it seems to converge on the retina being a product of evolutionary process.


And, for the record, I wanted to mention that I like this response:
...it's neither of the above - it's a good evidentiary example of how evolution is a non-directed process. Pay attention to it, Tai Chi.

[Foster Zygote]

It's well handy if there's stuff you don't want to see.

I just throw my towel over my head.

[joobz]

YEAH!!!!!

I missed the T'ai Chi "interesting" articles.

[joobz]

http://www.uncommondescent.com/intelligent-design/another-icon-of-bad-design-bites-the-dust/

Very interesting.
but very stupid....

[Jeff Corey]

Very interesting, "Hemorrhoids, Bad Design or Brilliant?" http://www.hemorrhoids.com

[strathmeyer]

The article didn't really make any sense to me, but I'd like to point out that if you invert the image going into your eye ("magical glasses") you'll easily adjust to it in about a week, and feel the same strange disorientation when you stop using them.

[wollery]

http://www.uncommondescent.com/intelligent-design/another-icon-of-bad-design-bites-the-dust/

Very interesting.

Nope.

[Cuddles]

The comments section makes my head hurt.

[Orangutan]

The article didn't really make any sense to me, but I'd like to point out that if you invert the image going into your eye ("magical glasses") you'll easily adjust to it in about a week, and feel the same strange disorientation when you stop using them.

You might have to follow the links to the actual research. The linked article is just babble. As far as the original research all that proves is given a poor start evolution can refine the design to a working model. No God necessary.

[Belz...]

Very interesting.

I KNEW it! I KNEW it!

If this thread didn't start with you saying the word "Interesting", I'd have been very dissapointed.



And why do I have an odd feeling of déjà vu ?

[Mojo]

I KNEW it! I KNEW it!

If this thread didn't start with you saying the word "Interesting", I'd have been very dissapointed.


This one didn't (http://forums.randi.org/showthread.php?t=81096).

[ponderingturtle]

You don't suppose that the phrase "the müller cells can capture and transmit as much light as possible" means as much as possible given the screwy backwards "design" do you? ;)

Hence it supports my theory of Bureaucratic Design. Animals are designed through a series of comities who are the low bid engineering bidders on the design contract.

If this theory only had predictive power it would be perfect I tell you.

[dakotajudo]

You might have to follow the links to the actual research.

How did you find the orignal research?

From this section in Dembski's


A recent article in PNAS now indicates that living optical fibers create a clear passage for light to the light-sensitive cells at the back of the eye. Concerning his research in this area, Andreas Reichenbach remarks, “Nature is so clever. This means there is enough room in the eye for all the neurons and synapses and so on, but still the Müller cells can capture and transmit as much light as possible.” Go here for a summary of the research as well as for a reference to the relevant PNAS article.

I followed the "go here" link, to this page http://www.theregister.co.uk/2007/05/01/eye_eye/ , but the only reference to a releveant PNAS article is this
The research, entitled "Müller cells are living optical fibers in the vertebrate retina" is published in the 30 April edition of the Proceedings of the National Academy of Sciences (PNAS)

But I can't find any such article under PNAS USA (there is no 30 April edition); searching for "Muller cells" and "living optical fibers" didn't turn up anything that matched. I did find this - http://www.pnas.org/cgi/content/abstract/103/47/17759 - searching for "Andreas Reichenbach".

Using google, I did find this: http://www.uni-leipzig.de/~pwm/kas/seminars/seminars.html , and PubMeding "Reichenbach" did turn up quite a few papers on retinal function, but nothing matching the Register article. Google hit a few other abstracts, but no published research.

[I less than three logic]

This one didn't (http://forums.randi.org/showthread.php?t=81096).
The best ones catch you off guard like that... now my side hurts.

:dl:

[Mercutio]

From a 2006 article, "Müller cells in the healthy and diseased retina", where Reichenbach is co-author, the abstract:Müller glial cells span the entire thickness of the tissue, and ensheath all retinal neurons, in vertebrate retinae of all species. This morphological relationship is reflected by a multitude of functional interactions between neurons and Müller cells, including a 'metabolic symbiosis' and the processing of visual information. Müller cells are also responsible for the maintenance of the homeostasis of the retinal extracellular milieu (ions, water, neurotransmitter molecules, and pH). In vascularized retinae, Müller cells may also be involved in the control of angiogenesis, and the regulation of retinal blood flow. Virtually every disease of the retina is associated with a reactive Müller cell gliosis which, on the one hand, supports the survival of retinal neurons but, on the other hand, may accelerate the progress of neuronal degeneration: Müller cells protect neurons via a release of neurotrophic factors, the uptake and degradation of the excitotoxin, glutamate, and the secretion of the antioxidant, glutathione. However, gliotic Müller cells display a dysregulation of various neuron-supportive functions. This contributes to a disturbance of retinal glutamate metabolism and ion homeostasis, and causes the development of retinal edema and neuronal cell death. Moreover, there are diseases evoking a primary Müller cell insufficiency, such as hepatic retinopathy and certain forms of glaucoma. Any impairment of supportive functions of Müller cells, primary or secondary, must cause and/or aggravate a dysfunction and loss of neurons, by increasing the susceptibility of neurons to stressful stimuli in the diseased retina. On the contrary, Müller cells may be used in the future for novel therapeutic strategies to protect neurons against apoptosis (somatic gene therapy), or to differentiate retinal neurons from Müller/stem cells. Meanwhile, a proper understanding of the gliotic responses of Müller cells in the diseased retina, and of their protective vs. detrimental effects, is essential for the development of efficient therapeutic strategies that use and stimulate the neuron-supportive/protective-and prevent the destructive-mechanisms of gliosis. In another article, gliosis (inflammation of the Müller cells) is seen as either reflecting or causing the neuronal degeneration which contributes to loss of vision after retinal detachment (even following reattachment surgery).

But, yeah, dakotajudo, I am not finding anything at all like the PNAS article claimed as the source. Indeed, there is no "30 April edition" (there is a May 1 edition, which does not have the article, and three earlier April editions, none of which have the article) at all. Like you, I searched the database (I looked for "vertebrate retina")--90 articles, no hits.

[Foster Zygote]

From a 2006 article, "Müller cells in the healthy and diseased retina", where Reichenbach is co-author, the abstract: In another article, gliosis (inflammation of the Müller cells) is seen as either reflecting or causing the neuronal degeneration which contributes to loss of vision after retinal detachment (even following reattachment surgery).

But, yeah, dakotajudo, I am not finding anything at all like the PNAS article claimed as the source. Indeed, there is no "30 April edition" (there is a May 1 edition, which does not have the article, and three earlier April editions, none of which have the article) at all. Like you, I searched the database (I looked for "vertebrate retina")--90 articles, no hits.

Now that's interesting!

[Gord_in_Toronto]

Now that's interesting!

Verrry interesting. Is it IDer policy to invent refertences knowing that its followers are to stupid to check them? I thought they only specialized in Quote Mining (qv). :mad:

[cyborg]

Off down the road again.

Going down the only road I've ever known.

[Belz...]

This one didn't (http://forums.randi.org/showthread.php?t=81096).

Yes, I noticed that. Still, this happened. (http://forums.randi.org/showpost.php?p=2571004&postcount=47)

[Wowbagger]

Let's not forget that these müller cells open up new avenues for investigating the evolution of the eye. There could be clues in their structure, and in the genetics that induce them, about the history of past selection pressures.

I wonder if the original report (which I could not find, at the moment) actually makes predictions of what we might find, if we study them more precisely.

Also, far from being an argument for ID, their discovery, by real biologists, actually shows us that evolution is a powerful-enough theory for increasing our scientific knowledge of the world.
Müller cells would never be discovered by an ID "scientist". They would have stopped studying the eye long before these sorts of details could ever be worked out.

[Mercutio]

Anyone speak German? His email is listed here. (http://www.uni-leipzig.de/~pfi/pfi/de/neurophysiologie/mitarbeiter/mitarbeiter.html) (yeah, I know he is probably a better English speaker than I am, but it only seems polite...)

[strathmeyer]

Ok, so I finally read the articles, and somebody's using the definition of invert that isn't "turn upside down". (http://www.arn.org/docs/odesign/od192/invertedretina192.htm) What the heck is the idea of maladaption? Evolution is about the best among a set of random choices, not somehow magically getting the best of everything. Are humans maladapted because they can't smash animals with their giant fists? Are monkeys maladapted because they aren't humans?

If we all lived in some strange future world, where not having a blind spot was obviously necessary for our survival, and some of the people were exactly like us alive today, but others had no blindspot? Then I guess I'd call the people with blindspots maladapted. Unless not having a blindspot also means that you'll die of cancer at an early age. See? I can make up stuff all day.

[Foster Zygote]

Are humans maladapted because they can't smash animals with their giant fists?

Ahem...

[joobz]

From a 2006 article, "Müller cells in the healthy and diseased retina", where Reichenbach is co-author, the abstract: In another article, gliosis (inflammation of the Müller cells) is seen as either reflecting or causing the neuronal degeneration which contributes to loss of vision after retinal detachment (even following reattachment surgery).

But, yeah, dakotajudo, I am not finding anything at all like the PNAS article claimed as the source. Indeed, there is no "30 April edition" (there is a May 1 edition, which does not have the article, and three earlier April editions, none of which have the article) at all. Like you, I searched the database (I looked for "vertebrate retina")--90 articles, no hits.
It is possible they were referring to an "early edition" publication date. If you go to that section, it has a number of articles listed available on April 30th. However, I couldn't find this article either.

[Belz...]

So if the inverted retina of mammals is a good design --- does that mean that the uninverted retina of octopods is a bad design?

Incidentally, what is so "brilliant" about having a blind spot?

That's what I was thinking, too.

They say it's a good design, after all, but they seem to forget WHY we call it a bad design in the first place.

Typical strawman argument.