Quite an eye opening article. Ha ha.
So intricate is the eye that its origin has long been a cause célèbre among creationists and intelligent design proponents, who hold it up as a prime example of what they term irreducible complexity—a system that cannot function in the absence of any of its components and that therefore cannot have evolved naturally from a more primitive form. Indeed, Charles Darwin himself acknowledged in On the Origin of Species—the 1859 book detailing his theory of evolution by natural selection—that it might seem absurd to think the eye formed by natural selection. He nonetheless firmly believed that the eye did evolve in that way, despite a lack of evidence for intermediate forms at the time.
Direct evidence has continued to be hard to come by. Whereas scholars who study the evolution of the skeleton can readily document its metamorphosis in the fossil record, soft-tissue structures rarely fossilize. And even when they do, the fossils do not preserve nearly enough detail to establish how the structures evolved. Still, biologists have recently made significant advances in tracing the origin of the eye—by studying how it forms in developing embryos and by comparing eye structure and genes across species to reconstruct when key traits arose. The results indicate that our kind of eye—the type common across vertebrates—took shape in less than 100 million years, evolving from a simple light sensor for circadian (daily) and seasonal rhythms around 600 million years ago to an optically and neurologically sophisticated organ by 500 million years ago. More than 150 years after Darwin published his groundbreaking theory, these findings put the nail in the coffin of irreducible complexity and beautifully support Darwin’s idea. They also explain why the eye, far from being a perfectly engineered piece of machinery, exhibits a number of major flaws—these flaws are the scars of evolution. Natural selection does not, as some might think, result in perfection. It tinkers with the material available to it, sometimes to odd effect.
It is amazing that species on such a different evolutionary track from humans have evolved such a similar eye — like the eagle. How did that happen?
I’m no questioning evolution, BTW; I just still find it amazing.
Did our eyes evolve a pickin’ long time ago when we and the eagle shared shared a common relative and then quit evolving? Or did they evolve nearly identically from all those million years ago?
Is this news?
This was all documented in a 1987 BBC Horizon documentary called “the Blind Watchmaker”.
This can be viewed at
http://video.google.com/videoplay?docid=6413987104216231786#
Best grab it before google delete it permanently.
#1 GregAllen
Probably a little of both. Similar environments (earth) will have similar pressures which result in similar structures.
Those blind fish that live in caves don’t really need eyes. Needing visual acuity to see prey from the air (eagles) and see predators hiding in savahnnah grass (apes) both result in complex eyes.
So, do beer goggles reverse evolution?
tee3,
>> Similar environments (earth) will have similar pressures which result in similar structures.
But nearly identical? Aren’t there quite a few ways eyes of vertebrates _could_ have evolved a bunch of different ways?
How many times are scientists going to describe something as the ‘nail in the coffin’. It’s like they have an agenda other than science.
Frequently these types of discoveries start with the assumption of evolution to prove evolution. We know things evolve and natural selection, therefore let’s see why this feature/organ/species gives an evolutionary advantage. It’s a bit of circular reasoning that leads to fantastic theories.
Lyin’ Mike: “Scientists” don’t describe anything as “nail in the coffin.” Non-scientist writing for non-scientists describe things that way.
What is evolution? Descent from common ancestors with modifications that have proved more adaptive to the given environment? Close Enough.
How similar is the Eagles Eye to the Human Eye? Isn’t it like 5-6 times more acute? And other “similar” eyes more able to see in the dark? etc.
Same kind of human folly that proclaims the Universe was “designed for man” when 99.9999999999999999% of it will kill us in an instant having nothing to do with humans.
The progression of genes as fully traceable in DNA has been called the greatest proof of evolution of life on earth that there is. Some structures in the Human Genome shared by the lowest of single celled organisms.
Truly awe inspiring.
#6, MikeN, I very seldom see any scientific argument that begs the question in any form comparable to the common religious argument of “complexity proves the existence of god because only god could create complexity.”
MikeN,
If they honestly think this is a “nail in the coffin” of creationism, they don’t understand Creationists!
Creationism is faith-based. Facts, logic and evidence are going to have limited impact.
“Scientific American” has become a contradiction in terms.
>> # 7 bobbo, in Repose said, on June 24th, 2011 at 6:35 am
>> How similar is the Eagles Eye to the Human Eye? Isn’t it like 5-6 times more acute? And other “similar” eyes more able to see in the dark? etc.
It’s very similar (I’m remembering an article I read years ago.) I’ll Google it…
I can’t find anything.
But, considering the hundreds (thousands?) of ways that a light-sensing organ COULD evolve, how is it that our very distant evolutionary relatives have such similar eyes?
(C’mon bobbo. Don’t let your anti-religious bigotry get in the way of a reasonable question. I’m not doubting evolution!)
Check this out:
The eyes of molluscs and vertebrates clearly evolved separately but look how similar in structure they are!
http://preview.tinyurl.com/6kf4h5u
The one on the left is the vertebrate.
I don’t care what you guys say — it’s still pretty amazing.
… oh, and the one on the right is an octopus.
http://preview.tinyurl.com/6kf4h5u
Taxed enough,
I’m a devout Christian and, just like millions of other Christians, we believe in Evolution. Including the Pope, for God’s sake!
I refuse to accept your premise that science has to be twisted into ridiculous knots in order to accommodate the way you read the bible.
It would be a strange universe indeed if all the bones of the human ape developed slowly over time, and all of the chemical/biological processes developed slowly over time, ALL as clearly evidence in comparative anatomy, but “the Eye” simply popped into existence?
How would that work?
And meanwhile all the “science” we see on tv such as earth evolving from a molten ball of rock with water arriving from asteroids all slowly cooling, freezing, warming over billions of years with all atoms except hydrogen and helium being the detritus of exploded stars all coming together by gravity. And then human popped into existence.
Ha, ha. The Eye didn’t evolve only if every friggin thing we know about the universe is wrong. I’d call that somewhat of a hurdle, philosophically speaking. Common Sense?
Greg Allan–somehow when you say “Its still pretty amazing” it just doesn’t “sound like” you are “only” saying its pretty amazing.
I suppose the direct answer was already given above: parallel evolution wherein many species/structure form in pretty much the same way in response to pretty much the same environmental conditions/pressures.
Now, what would be “amazing” would be if nocturnal animals had the same eye as daytime animals? But I’ll go back to the premise again: just “how similar” is an Eagles Eye to the Human Eye, to the Bat’s Eye, to a cat’s eye etc? Iris/Not, Eyelid/Not, Extra Lids/Not, Cone Ratio’s, so much more? What makes them “amazingly similar” and not tellingly different?
Hubris–making god in our own image. Yes, everything perfect for our enjoyment.
Greg Allan–does your faith inform you about ANYTHING in the real world==or only about those things that cannot be disproven?
Not a very helpful religion being so constrained, with so many competing ideologies all claiming exactly the same attributes?
Only science explains the world we live in. Only science is bringing the family of man together.
Quite Ironic.
Won’t change any minds. Creationist believe that they already have all the answers. As the creationist bumpersticker so eloquently states “God said it. I believe it. That settles it.”
Nikola Tesla’s View On The Human Eye.
http://unhypnotize.com/articles-newsletters/46477-nikola-teslas-view-human-eye.html
Good point Yank–but you give too much credit to limit this certainty to only “creationists.” Greg Allen “believes” in evolution as amazing as it is and has the same certainty in all things upon which his religions calls upon him to be certain.
Religion works that way. Just like science they will say: the dogma of science no different than those of religion.
Like believe only xyz from religion is the same as believe only what can be demonstrated from science. See how that is the very same thing?
Yea, verily.
Are the real Bobbo? If so, I sense you’ve taken a shift on the subject of science and religion. Maybe I’m not following your logic.
Of course my faith and religion informs my real world. Science doesn’t tell me whether I should help the poor. for example.
But science gives me tools to understand the physical world.
I’ve been hammered here for saying this but here I go again… I have a unified theory of science and theology
I believe these disciplines (and more) are ultimately trying to answer the same question but are focusing on different aspects.
By the way bobbo, I believe in evolution. I don’t “believe” in evolution.
>> bobbo, in Repose said, on June 24th, 2011 at 7:34 am
>> Greg Allen “believes” in evolution as amazing as it is and has the same certainty in all things upon which his religions calls upon him to be certain.
Once again, you terribly misunderstand religion, bobbo. The bible is filled with doubters. The history of religion is filled with doubters. And these are the heroes!
>> # 21 Deprogrammer9 said, on June 24th, 2011 at 7:31 am
>> Nikola Tesla’s View On The Human Eye.
>> http://unhypnotize.com/articles-newsletters/46477-nikola-teslas-view-human-eye.html
I love Tesla but, holy smokes, that was hard to follow! It did seem like he had some major facts wrong.
for example:
>> the eye is the means through which the human race has acquired the entire knowledge it possesses, that it controls all our motions, more still, all our actions. There is no way of acquiring knowledge except through the eye.
This isn’t even close to being true, is it?
Ha, ha. FUD from the caring christian.
Sophisticated bible thumpers have come to learn the total distinction between religion/faith and science/reality.
And everything you “know” comes from science. From the “real” world. From its demonstrability, reproducability. No need for faith. No requirement to believe. Do what you think works. Science is about what works, faith about what has no application in the real world at all.
You do make about the “best” argument for falsely trying to confuse/equate the two when you say “Science doesn’t tell me whether I should help the poor.” Can we be more specific? How to grow more food to feed the poor? How is that accomplished? Does faith or science inform that decision?
And what good does it be to be informed yet not act on it? The starving poor are all over the third world. Why don’t you pledge all that you can to feed these people Greg Allan? Nearer to god you would be.
The twin pillars of the devout: ignorance and hypocrisy.
I could post as bobbo, the evangelical anti-theist, but I am in Repose. Resting. What do you recall from past discussion that make you think I have changed? I don’t think so but any inconsistency would be of interest. To me. Your mileage may differ.
Greg–how do you resolve that other religions come to different answers with your same certainty? What would you “lose” by maintaining your humanity and just losing what cannot be proven in your best thoughts? Why not accept a mystery as a mystery?
I quoted “believe” to emphasize the connection with “amazing.” Curious as I can say the same things. Quotes perhaps because I only believe in things that can be demonstrated whereas you also believe in things that cannot be demonstrated. Clearly your belief structure is not the same as mine. Some other word is needed only clumsily approached by putting the same letters in quotes.
Interesting ideas. You never have responded to the Epicurus Logic Block:
“Is God willing to prevent evil, but not able?
Then he is not omnipotent.
Is he able, but not willing?
Then he is malevolent
Is he both able and willing?
Then whence cometh evil?
Is he neither able nor willing?
Then why call him God?”
What does believing matter when it makes no sense? Only what can be demonstrated makes sense.
Makes sense?
So, Tesla overstated his case to make the point. At least he doesn’t want to punish us for all eternity if we disagree? He just doesn’t love us that much?
Ha, ha.
GregAllan: “But — no — organs don’t just spontaneously pop out.”
Speak for yourself, buddy.
#29, HAR
(Though that is becoming less of a problem as I get older . . .)
Bobbo,
It’s kind of funny, coming from you, to be accused of hyper certainty!
I have always conceded that you could be right and I could be wrong on this religious debate. I honestly believe that atheists have things to teach we religious people.
But you! Talk about cock sure!
As for being amazed at the world around me — I suppose that could be a religious impulse. I never thought-so before, because I’ve spoken with non-religious scientists who share my marvel. It happened again just last month , actually.
Well, I gotta go.
>> Taxed Enough Already Dude said, on June 24th, 2011 at 9:04 am
>>> #13 The eyes of molluscs and vertebrates clearly evolved separately but look how similar in structure they are!
>> Resurrecting that old canard?
What’s canardy about being amazed that the human eye is so similar to the eye of an octopus. We have 70lb octopus up her in the northwest and I’ve looked them in the eye. The eye looking back seems almost human. That amazes me from a species so different.
>> Of course structures have similar purpose will be similar.
Not “of course” at all! The eye of the octopus could have evolved a 1000 different ways. Yet, it evolved to look like a human’s. That’s takes a little ‘splaing, if you ask me.
One explanation is that God just arbitrarily decided to do it that way. I’m more interested in the evolutionary explanation.
Well, I gotta go.