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Darwin's greatest challenge tackled
European Molecular Biology Laboratory ^ | 10/28/2004 | EMBL

Posted on 11/03/2004 5:11:47 PM PST by general_re

Darwin's greatest challenge tackled
The mystery of eye evolution

Researchers provide concrete evidence about how the human eye evolved

When Darwin's skeptics attack his theory of evolution, they often focus on the eye. Darwin himself confessed that it was 'absurd' to propose that the human eye, an 'organ of extreme perfection and complication' evolved through spontaneous mutation and natural selection. But he also reasoned that "if numerous gradations from a simple and imperfect eye to one complex and perfect can be shown to exist" then this difficulty should be overcome. Scientists at the European Molecular Biology Laboratory [EMBL] have now tackled Darwin's major challenge in an evolutionary study published this week in the journal Science. They have elucidated the evolutionary origin of the human eye.

Researchers in the laboratories of Detlev Arendt and Jochen Wittbrodt have discovered that the light-sensitive cells of our eyes, the rods and cones, are of unexpected evolutionary origin ­ they come from an ancient population of light-sensitive cells that were initially located in the brain.

"It is not surprising that cells of human eyes come from the brain. We still have light-sensitive cells in our brains today which detect light and influence our daily rhythms of activity," explains Wittbrodt. "Quite possibly, the human eye has originated from light-sensitive cells in the brain. Only later in evolution would such brain cells have relocated into an eye and gained the potential to confer vision."

The scientists discovered that two types of light-sensitive cells existed in our early animal ancestors: rhabdomeric and ciliary. In most animals, rhabdomeric cells became part of the eyes, and ciliary cells remained embedded in the brain. But the evolution of the human eye is peculiar ­ it is the ciliary cells that were recruited for vision which eventually gave rise to the rods and cones of the retina.

So how did EMBL researchers finally trace the evolution of the eye?

By studying a 'living fossil,' Platynereis dumerilii, a marine worm that still resembles early ancestors that lived up to 600 million years ago. Arendt had seen pictures of this worm's brain taken by researcher Adriaan Dorresteijn [University of Mainz, Germany]. "When I saw these pictures, I noticed that the shape of the cells in the worm’s brain resembled the rods and cones in the human eye. I was immediately intrigued by the idea that both of these light-sensitive cells may have the same evolutionary origin."

To test this hypothesis, Arendt and Wittbrodt used a new tool for today’s evolutionary biologists – 'molecular fingerprints'. Such a fingerprint is a unique combination of molecules that is found in a specific cell. He explains that if cells between species have matching molecular fingerprints, then the cells are very likely to share a common ancestor cell.

Scientist Kristin Tessmar-Raible provided the crucial evidence to support Arendt's hypothesis. With the help of EMBL researcher Heidi Snyman, she determined the molecular fingerprint of the cells in the worm's brain. She found an opsin, a light-sensitive molecule, in the worm that strikingly resembled the opsin in the vertebrate rods and cones. "When I saw this vertebrate-type molecule active in the cells of the Playtnereis brain – it was clear that these cells and the vertebrate rods and cones shared a molecular fingerprint. This was concrete evidence of common evolutionary origin. We had finally solved one of the big mysteries in human eye evolution."

Source Article
Ciliary photoreceptors with vertebrate-type opsins in an invertebrate brain.
D. Arendt, K. Tessmar-Raible, Snyman, Dorresteijn, J. Wittbrodt
Science. October 29, 2004.


TOPICS: Culture/Society; News/Current Events; Philosophy
KEYWORDS: crevolist; darwin; evolution; eye; sight
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1 posted on 11/03/2004 5:11:47 PM PST by general_re
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To: PatrickHenry

Boink.


2 posted on 11/03/2004 5:12:25 PM PST by general_re (Drive offensively - the life you save may be your own.)
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To: general_re

Man! God's going to be pissed that you found out his secret!


3 posted on 11/03/2004 5:15:30 PM PST by Shortwave (Supporting Bush was a duty one owed to the fallen. Now, it is an honor.)
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To: general_re
"In the beginning...God."

'nuff said.

4 posted on 11/03/2004 5:19:57 PM PST by doingtherightthing (I stand with President Bush)
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To: general_re; PatrickHenry
I've been assured that science will never explain the origin of the eye. Therefore, this article is wrong.
5 posted on 11/03/2004 5:21:56 PM PST by VadeRetro (A self-reliant conservative citizenry is a better bet than the subjects of an overbearing state. -MS)
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To: general_re

eyeball ping


6 posted on 11/03/2004 5:21:57 PM PST by escapefromboston (manny ortez: MVP)
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To: general_re
This hasn't been too much of a secret. Even in the days of Darwin and Wallace, zoologists had the eye argument nailed. There are some interesting technical objections to the theory of evolution, but the 'half-eye' has never been one of them.
7 posted on 11/03/2004 5:22:16 PM PST by Starve The Beast (I used to be disgusted, but now I try to be amused)
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To: Starve The Beast

The eye cells have it!


8 posted on 11/03/2004 5:23:55 PM PST by WestVirginiaRebel ("Vote for Kerry for your own security. I'm Osama Bin Laden and I approved this message.")
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To: general_re
Yes, and all those fossilized ape skulls they occasionally find in Africa and the National Geographics staff fawn over, are really our uncles too. NOT!
9 posted on 11/03/2004 5:25:26 PM PST by Imabeliever (One need not be demon possessed to convert to Islam, but soon will be.)
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To: general_re
http://www.sciencedaily.com/releases/2004/02/040218074335.htm

Salamanders don't get glaucoma because they can readily regenerate retinal cells. The same is true of newts, frogs, and some types of fish. "We're trying to understand the remarkable regenerative powers of these lower vertebrates, and through this understanding, develop strategies to stimulate regeneration in the human retina," Reh said.

While salamanders can regenerate retinal cells through their life, many other species lose this ability as they age. "At some point in each species life cycle, the stem cells in the retina make a transition from a regenerative cell to a cell that will make a scar in response to injury, like the cells that cause scars in the spinal cord," Reh said. "Chickens make the transition a few weeks after hatching in most of their retina, though they retain some limited capacity to regenerate retinal cells throughout life. In rats, it's only a matter of a few days after the cells are generated that they lose their ability to regenerate other retinal cells."

Human retinas seemingly can't repair themselves, yet in recent studies human retinal cells have grown new neurons when cultured in the laboratory. "The hope is that many of the molecular and cellular mechanisms necessary for regeneration, that serve amphibians so well, are still in place in humans," Reh said. "Future studies from the nervous system, as well as other organ systems, should enable us to define the roadblocks in the regenerative process, and develop strategies to go around them."

10 posted on 11/03/2004 5:26:04 PM PST by Fitzcarraldo
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To: general_re

Now that's real interesting, a light sensitive cell "evolving" in a dark area. It couldn't be that God was getting it ready, oh perish the thought /sarcasm


11 posted on 11/03/2004 5:29:37 PM PST by HiTech RedNeck
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To: HiTech RedNeck
It couldn't be that God was getting it ready...

Could be. Perhaps our knowledge of how He did it is evolving as well ;)

12 posted on 11/03/2004 5:42:53 PM PST by general_re (Drive offensively - the life you save may be your own.)
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To: VadeRetro; jennyp; Junior; longshadow; RadioAstronomer; Physicist; LogicWings; Doctor Stochastic; ..
Evolution Ping! This list is for the evolution side of evolution threads, and maybe other science topics like cosmology.
See the list's description in my freeper homepage. Then FReepmail me to be added or dropped.
13 posted on 11/03/2004 5:47:25 PM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: PatrickHenry

"They have elucidated..."


Well, he just lost half the Creationists by using that big word.


14 posted on 11/03/2004 6:15:57 PM PST by Blzbba (Conservative Republican - Less gov't, less spending, less intrusion.)
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To: general_re

I see. ;)


15 posted on 11/03/2004 6:22:47 PM PST by <1/1,000,000th%
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To: Blzbba
They have elucidated..."

Well, he just lost half the Creationists by using that big word.

He sure lost the dyslexics--they think he's discussing plane geometry...

16 posted on 11/03/2004 6:25:20 PM PST by grey_whiskers (The opinions are solely those of the author and are subject to change without notice.)
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To: <1/1,000,000th%
I see. ;)

No, "Eye" see.

Ba-dum-BUM!

17 posted on 11/03/2004 6:26:51 PM PST by grey_whiskers (The opinions are solely those of the author and are subject to change without notice.)
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To: general_re; PatrickHenry
Ah, but of what possible survival benefit was the original ability to detect light?

For a well-thought out explanation go here -- and then read the book.

18 posted on 11/03/2004 6:28:02 PM PST by aculeus
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To: <1/1,000,000th%
I see. ;)

How long until a Christian brings in John 9:41 out of context?

Jesus said, "If you were blind, you would not be guilty of sin; but now that you claim you can see, your guilt remains."

19 posted on 11/03/2004 6:29:34 PM PST by grey_whiskers (The opinions are solely those of the author and are subject to change without notice.)
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To: general_re

Didn't Hume base an early version of argument-from-design upon the eye?


20 posted on 11/03/2004 6:30:22 PM PST by grey_whiskers (The opinions are solely those of the author and are subject to change without notice.)
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To: general_re

Read "Darwin's Black Box" by Michael Behe.

We are the product of intelligent design.

I find it amazing that the evolutionists can believe that all of the universe can spring from a “Big Bang” (the size of the head of a pin) but do not believe that all was created from nothing.


21 posted on 11/03/2004 6:48:44 PM PST by FatherofFive
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To: general_re

First tell me where the brain cells came from?

And, oh by the way, what went BANG! in the first place?


22 posted on 11/03/2004 6:50:27 PM PST by jpw01 (Freep the world!)
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To: general_re

Election's over, now we can go back to arguing about evolution and whether predestination is true.


23 posted on 11/03/2004 6:52:51 PM PST by JusPasenThru (Kerry: Carter without the competence, Clinton without the integrity.)
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To: jpw01; FatherofFive

The Big Bang is not a biological theory.


24 posted on 11/03/2004 6:54:18 PM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: PatrickHenry

I know, but if you believe evolution was the origin of life, you would believe the Big Bang theory too.


25 posted on 11/03/2004 6:55:21 PM PST by jpw01 (Freep the world!)
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To: jpw01
I know [The Big Bang is not a biological theory], but if you believe evolution was the origin of life, you would believe the Big Bang theory too.

The theory of evolution is not involved with the origin of life, but rather with the proliferation of species, after life has begun.

As for the Big Bang, it's a theory that is only about 50 or 60 years old, and there were loads of biologists who accepted the theory of evolution before the Big Bang theory was ever dreamed of. They're quite unrelated.

It's true, however, that a science-minded person, who is impressed by evidence and rational thought, is likely to be favorably impressed by both theories; but that doesn't mean that they're related topics.

26 posted on 11/03/2004 7:10:09 PM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: PatrickHenry
The theory of evolution is not involved with the origin of life, but rather with the proliferation of species, after life has begun.

I agree, but there are those out there who don't understand that. My point is that they have the same mentality as the people that believe that the universe originated from nothing that suddenly when BANG.
27 posted on 11/03/2004 7:13:45 PM PST by jpw01 (Freep the world!)
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To: jpw01
My point is that they have the same mentality as the people that believe that the universe originated from nothing that suddenly when BANG.

As I said, those who are impressed by evidence and rational thought will be impressed by well-supported scientific theories. The evidence supports evolution, and the Big Bang too. What's a rational person supposed to do?

28 posted on 11/03/2004 7:23:42 PM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: general_re

The article mentions "the perfection of the human eye. The human eye is far from perfect. Eagles and falcons have much better eyes than we do.


29 posted on 11/03/2004 7:26:47 PM PST by Wacka
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To: PatrickHenry

Think. Answer the question in my first post. What went bang?


30 posted on 11/03/2004 7:30:15 PM PST by jpw01 (Freep the world!)
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To: jpw01
What went bang?

I donno. What's your point?

31 posted on 11/03/2004 7:33:46 PM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: PatrickHenry

The big bang may well have happened, but it was not the origin of the universe. Something had to have been there to go bang, or it couldn't have happened.

Evolution happens, we know that. It could not have been the origin of life, however, or there would have been nothing to evolve.

The "scientific" explainations don't explain the origins of either. God is the origin.


32 posted on 11/03/2004 7:38:37 PM PST by jpw01 (Freep the world!)
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To: general_re

Now I know we are getting back to normal, more threads exposing the crevos as cranks.

Thank God!


33 posted on 11/03/2004 7:46:31 PM PST by Central Scrutiniser (Laugh While You Can, Monkey-Boy!!!!)
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To: FatherofFive

it seems to me, that God could have created a universe with or without evolution operating, and with or without a big bang. If He chose to create a universe in which evolution operates, why do people want to challenge that?


34 posted on 11/03/2004 8:07:47 PM PST by drhogan
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To: Central Scrutiniser; PatrickHenry

So many fresh, new faces. So many tired, old posts ;)


35 posted on 11/03/2004 8:08:59 PM PST by general_re (Drive offensively - the life you save may be your own.)
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To: Wacka
Eagles and falcons have much better eyes than we do.

Giant squids seem to have better eyes too. The evolutionary path is somewhat different though.

36 posted on 11/03/2004 8:31:11 PM PST by Doctor Stochastic (Vegetabilisch = chaotisch is der Charakter der Modernen. - Friedrich Schlegel)
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To: jpw01; PatrickHenry
what went BANG! in the first place?

I'll jump in here, since this is one of my favorite issues.

Same answer as where God came from . . .

I've argued this design issue extensively on another thread. The eye isn't particularly well designed. That is an opinion. Go out on a clear day, look up at the blue sky and notice all those little black things racing across the sky. Those are the red blood cells feeding the rods and cones that you see with, racing about feeding those same rods and cones. Disturbing your vision.

Because our eyes evolved from light sensitive patches under the skin, they are fed from above. As the eyes deepened for more efficiency, they kept the same configuration.

Squids, however, evolved in the cold water of oceans and their eyes are fed from beneath rather than from above, because it was more efficient to provide nutrients not being exposed to the cold water, from the beginning.

"Intelligent Design" is in the eye of the beholder.

37 posted on 11/03/2004 9:35:48 PM PST by LogicWings
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To: general_re

Election's over, out to play placemarker.


38 posted on 11/03/2004 10:03:03 PM PST by js1138 (D*mn, I Missed!)
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To: jpw01

Did Einstein wrap his mind around the concept of God always was?


39 posted on 11/03/2004 10:09:21 PM PST by Ben Chad
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To: LogicWings
I'll jump in here, since this is one of my favorite issues.

Same answer as where God came from


Different question entirely. Why did God have to come from anywhere? God is infinite, and therefore, always was and always will be. God created time for our benefit, but is not bound by His creation.

The universe, on the other hand, had to have a beginning.
40 posted on 11/04/2004 3:39:51 AM PST by jpw01 (Freep the world!)
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To: Imabeliever
"Yes, and all those fossilized ape skulls they occasionally find in Africa and the National Geographic staff fawn over, are really our uncles too. NOT!"

Proof that man descended from apes, in most movies where people are being chased, they always run upstairs.:)
It is the same as climbing a tree.:)
Only Benny Hill always runs around, while being chased.
41 posted on 11/04/2004 3:51:36 AM PST by HuntsvilleTxVeteran (Dan Rather called Saddam "Mister President and President Bush "bush")
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To: Fitzcarraldo

Behold the power of Salamanders!

[LOL!]


42 posted on 11/04/2004 5:15:22 AM PST by Salamander (Pirates of the Appalachians)
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Comment #43 Removed by Moderator

To: jpw01

Of course evolution doesn't explain the origin of life. It's not supposed to. It is a theory about the changes that life underwent after it formed. There are scientific theories about the origin of life, however. These have much less convincing evidence in their favor than does evolution. Scientists are still working on this issue. On the origin of the universe, this too has nothing to do with whether evolution is true or not. The big bang theory exists to explain the way the universe developed. There is a good deal of solid evidence to support this theory just as there is for evolution. It strikes me that neither evolution or big bang theories are incompatible with creationism, however. Is it not possible that God created the universe via the big bang and then created life (whether via a special act of creation or abiogenisis or any other method is irrelevant), and then created the mechanism of evolution to allow for the wide diversity of life we see now? Could not "let there be light" refer to a big bang? (In the earliest stages of the universe, according to the big bang, light is all there is. Matter is created from the light) The Bible also gives the order of creation of types of life in essentially the same order as the theory of evolution predicts. Maybe the scientific theories and the Bible are consistent with each other. There is only one truth. If science and religion appear to contradict each other, the problem is with our understanding of either science, the Bible, or both.


44 posted on 11/04/2004 5:39:06 AM PST by stremba
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To: general_re; PatrickHenry

Whooohooo! Back to science and evolution. :-)


45 posted on 11/04/2004 6:40:17 AM PST by RadioAstronomer
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To: RadioAstronomer

Yeh, I got real tired of Kerry/Bush babble.


46 posted on 11/04/2004 7:48:31 AM PST by furball4paws ("Facts are very stubborn things" - Peter Wimsey)
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To: stremba

I have no problem with either theory, as long as they are not used to explain the origins of life or the universe, which is often the case.


Science is a very good way of trying to understand all that God has created. It is, however, a very ineffective way of disproving God's existence.


47 posted on 11/04/2004 7:55:23 AM PST by deaconjim (Freeper formally known as jpw01 (Freep the world!))
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To: FatherofFive
I find it amazing that the evolutionists can believe that all of the universe can spring from a “Big Bang” (the size of the head of a pin)

The origins of the universe is not a topic covered by the TOE.

48 posted on 11/04/2004 9:40:49 AM PST by Modernman (Giving money and power to government is like giving whiskey and car keys to teenage boys. - P.J.)
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To: Modernman

However, the origins of cute bunnies is a topic covered by the TOE!

Check here for other questions: The Official God F.A.Q.

49 posted on 11/04/2004 11:02:29 AM PST by balrog666 (It is impossible for a man to learn what he thinks he already knows.)
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To: balrog666
However, the origins of cute bunnies is a topic covered by the TOE

I bet those bunnies would be delicious.

50 posted on 11/04/2004 11:09:07 AM PST by Modernman (Giving money and power to government is like giving whiskey and car keys to teenage boys. - P.J.)
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