Darwin And Irreducible Complexity
In On The Origin Of Species, the work in which Charles Darwin first put forth the theory of evolution, he wrote:
And I’d like to think that Darwin (unlike many of his scientific successors) would be intellectually honest enough to not just ignore the implications of such an argument.
“If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive slight modifications, my theory would absolutely break down.”Had Darwin lived an additional 120 years or so, he would’ve become familiar with the compelling argument of irreducible complexity, which basically demonstrates that, indeed, there are many complex biological systems that “could not possibly have been formed by numerous, successive slight modifications.”
And I’d like to think that Darwin (unlike many of his scientific successors) would be intellectually honest enough to not just ignore the implications of such an argument.
35 comments:
Luke, did you read the rest of the Wikipedia article and/or the sub-articles dedicated to explaining the evolution of the eye or flagella? This is not an article about how irreducible complexity shatters evolution, it is an article about how some people mistakenly believe that it does.
Have you watched the NOVA series Intelligent Design on Trial? It is very good and involves top experts going head to head on this issue.
I am no scientist, so the technical stuff is above me. But this is how it inevitably goes. ID makes the absolute claim of irreducible complexity. Evolution posits one or multiple theories of reducibility that can be explained by the theory. ID struggles to hold on to the absolute claim by further claiming that the offered reducibility theories are highly improbable. Evolution admits that the entire process looks improbable because we are looking back on it from after the fact.
Unless ID can come up with something that really cannot be explained, then it will continue to have articles written about how some people think it disproves evolution instead of how it actually does.
At best, the irreducible complexity argument is an appeal to ignorance. It can be summarized by this: "I can't think of any way to explain this using the theory, therefore it is inexplicable."
But when someone comes along and offers a cogent explanation, the bubble is burst.
Yeah, unfortunately David's right. Most of the "scientific" arguments against evolution aren't really scientific at all, and irreducible complexity is one such argument (alongside Dembski's similarly-debunked "specified complexity" and several others).
Irreducible complexity relies on a false assumption. Adaptations that are now part of a system that is seemingly "irreducibly" complex could conceivably have been used for some other purpose first and then seen the original purpose later become obsolete. IC posits that this is impossible, but it's a logically fallacious "argument from ignorance," as David was saying.
When Professor Behe, the main proponent of IC, was confronted with relatively overwhelming evidence regarding the human immune system (one of his test cases) at the Dover trial in 2005, he couldn't say anything other than that the evidence "wasn't enough." He actually admitted during the trial that "there are no peer reviewed articles by anyone advocating for intelligent design supported by pertinent experiments or calculations which provide detailed rigorous accounts of how intelligent design of any biological system occurred." I would contend that he's being intellectually dishonest by promoting irreducible complexity as science.
This is kind of funny timing...I've actually been looking into evolution a lot lately because of a video series we've been using at church, so you caught me at a time when it's all pretty fresh in my mind. I'm finding it's not unreasonable to reconcile most of evolutionary biology to my own Christian theology, which is fairly comforting.
On the other hand, it is discomforting to me when Christians frame the debate as creation vs. evolution (though atheists have done this too) when the two are not mutually exclusive. I think it's going to turn an increasingly science-oriented population against Christianity as they study science and see that it supports evolution. It doesn't have to work that way.
David and John,
This is long, so I have to break it up into pieces.
I’ll lump my response to the two of you together, since much of what you said overlapped.
(1) David condescended to explain to me that the Wikipedia article I linked to doesn’t say what I thought it said (i.e. that IC “shatters evolution”), and while I appreciate your helpfulness in this regard, I didn’t link to the article for support.
What the article does provide is a good definition of IC, a concept that a lot of people aren’t familiar with.
In addition to that, the article says that IC is rejected by the scientific community as a whole, but this isn’t groundbreaking news, and was also part of the original point of my post.
(2) I’ll start by echoing David’s confession that I’m no scientist, so a lot of this will be in laymen’s terms.
To some degree, both of you make mention of the argument that IC isn’t really irreducible—that the proteins or “pieces” needed to make complex systems could have already been present in the organism and used in some other capacity, and then later could have been “borrowed” to create the complex system in question. This argument is called “Co-option,” and it’s not something that IC proponents haven’t heard before.
Using the example of the bacterial flagella, co-optionists point out (and this is from the Wikipedia article) that the base of the flagella is similar to a needle-like structure used by pathogens to inject toxins into cells. According to the article, “The needle’s base has ten elements in common with the flagellum, but it is missing forty of the proteins that make a flagellum work.”
So that hardly solves the problem, as you’re still forty proteins short of a functional flagellum—the gap to functionality hasn’t really been bridged at all. You still need to find several other structures and account for their combination, which is at best highly implausible.
(3) Science, at its most basic, is about obtaining evidence through observation, and then following the evidence to its conclusion, regardless of whether or not that conclusion agreed with your initial hypothesis.
In my original post, I was actually giving somewhat of a tip of the hat to Darwin, because I think that’s exactly what he did. Based on the observations and information he had, he drew what he thought was a reasonable conclusion.
But here’s the thing: that’s exactly what a lot of ID proponents are doing. Not all of them are evangelical Christians who are out to prove that Jesus Christ is the Son of God. Many of them, Behe included, actually started out toeing the party line on evolution until their own research and experiences gave them honest doubts, and for that, they are lampooned and regarded as pseudo-scientists.
But really, when you look at it, the ID approach is no less reasonable than the evolutionary approach—it’s only “unscientific” because we’ve embedded within the definition of “scientific” that an “outside actor” can’t be involved in any way.
To summarize the two positions:
ID approach: When you look at some of the complex systems of life, especially at things like DNA, the sophistication of which, even now, we can’t begin to duplicate, statistically, it is unfathomably improbable that these complex systems occurred purely through natural selection. It seems that an intelligence must have played a part in the initial design.
Non-ID approach: Certainly these systems are incredibly complex, and certainly it is improbable for these systems to have developed purely through natural selection, but here we are, so it must have happened.
Either way, there are some significant assumptions at play: with the IDers, since it seems impossible, the assumption is that something else (i.e. intelligence) must be at work. With those who reject ID, the assumption is that since we know nothing else could be at work here, it must have been possible, no matter how impossible it seems.
It is a joke for those who reject ID to act like they have some sort of logical high ground based on such reasoning. I’m not going to deny that ID requires faith because you can’t prove the existence of the Designer, but the contrary view requires faith as well—just faith in unproven, human theory.
(4) John brings up what is becoming an increasingly popular mantra among liberal Christians (and I’m not using “liberal” derisively), that belief and evolution aren’t mutually exclusive (this is somewhat ironic, because at the same time, a growing number of atheists, like Richard Dawkins, are insisting that belief and evolution are mutually exclusive).
To a degree, that’s true. Evolution and natural selection occurs, but in a micro sense. In industrial London, black moths blended in better with soot-covered trees than lighter-colored moths did, and this allowed them to escape predators. This is observable; we know it happened. Furthermore, this doesn’t present any disharmony with faith, Biblical accounts, etc.
But what hasn’t been observed is evolution in the macro sense, which is what Darwin proposed: over time, these adaptations add up to form dramatically different species.
This is where the mutual exclusivity appears: you can’t believe in both God and macroevolution without severely “dumbing down” the beginning of life that is revealed in the Bible.
I believe in a literal interpretation of Genesis 1, but even that’s not really what I’m talking about. Throughout Scripture, man is treated as the crowning achievement of God’s creation—formed in the image of God, superior to other creatures, capable of sin and valuable enough to redeem. All in all, unique from the rest of creation.
I’m sorry, but that simply can’t be reconciled with “a few random mutations removed from a Neanderthal”.
Can you believe in God and evolution as proposed by Darwin? Only if your view of God is completely unorthodox and you regularly disregard Scripture. Now from his previous writings, I know that describes David pretty well (and I don’t mean that offensively), but I wouldn’t have thought it described you.
(5) As an aside, I know that the popular thing is to lump ID and creationism in together, but they’re not exactly the same.
ID suggests that “God” or some “Intelligence” designed the world, life, etc., but still leaves room for evolution to work beyond that. Natural selection plays a huge part in the world; it just doesn’t explain everything.
Creationism goes a step further, and says that not only did God create the world, but He did so as described in Genesis, one step, one species at a time (and you can sub-divide between Young Earth and Old Earth, etc.). For the record, as laughable as that may seem to you all, this is where I am.
My question to the two of you, and this is just for my own curiosity: what do you believe? To the degree that both of you consider yourselves to be Christians of some sort (I think), I would think that you believe that the universe does have an Intelligent Designer. So:
—Do you reject ID as “science” while personally, as a matter of “religion” believe in a Designer?
—Do you support ID as defined above but reject it when it’s used interchangeably with Creationism?
—Do you support ID but reject IC?
—Do you reject a Designer altogether?
1. Sorry for being condescending. I didn't that as much as I meant to use that as a way of book ending my argument.
2. We can't both admit our lack of expertise and then try to recreate the arguments between experts. I have no idea how proteins mutate or how the theoretical bridge between the structures works in the minds of scientists, so this is not ever going to be a useful discussion. There are useful observations to be made from outside the specific scientific arguments. First, that the IC claim is that there is no way that the gap could be bridged. Second, Evolution proposes one or more theories as to how the gap could have been bridged. Those theories become widely accepted in the scientific community while the original IC claim gains no traction.
3. You are right about science being about testable hypotheses. What is the hypothesis of IC?
4. To me, it looks like extremists on both sides argue that the two are mutually exclusive, but that doesn't make it true for the millions of ideological moderates.
I think my personal views would just be a distraction from this, but I will try to post them when I get a chance.
Fantastic discussion. I really enjoy reading everyone’s thoughts.
Luke, excellent thoughts. I love the line: “I’m not going to deny that ID requires faith because you can’t prove the existence of the Designer, but the contrary view requires faith as well—just faith in unproven, human theory”
I have always loved the arguments against the irreducibly complex (IC) view. Here is a classic one (straight from the wiki article and is similar to other articles I have read):
"One likely chain of development is that the eyes originated as simple patches of photoreceptor cells that could detect the presence or absence of light"
Unfortunately, what seems to escape the grasp of EVERY scientist that has ever held the argument against IC is this: Where did the "simple patches of photoreceptors" come from?
If you want to explain macro-evolution you cannot START with something (i.e. STARTING the evolution of the eye with photoreceptors)... if you do... you haven’t started at all, but continued. Take me from nothing to the eye, then I will be impressed.
I guess photoreceptors really arent all that simple... are they?
David, you asked: “what is the hypothesis of IC?” I am assuming (maybe incorrectly) that you think that there is no hypothesis for those that hold the IC view. I know many Christians who are scientists (they are even evangelical Christians) that are experts (yes, world renown experts) in their field that continue to do high level research because they are interested in how the body works. I have never heard any of them say: “Well, its irreducibly complex… we shouldn’t study it.”
They have many hypotheses.
I am not sure what particular hypothesis you are looking for, but if you let me know I can ask them and then let you know.
Can an orchestra assemble itself and perform a masterpiece?
An evolutionist would say: Sure! You start with a metal tube and after millions of years it curves itself around perfectly to become a trumpet. At the same time some other metal tubes decided to not be a trumpet, but to be big and round, and they were caught in some fabric and formed drums. Then, through a series of events (that’s my favorite… the “series of events” argument) we now have an orchestra playing! And what-do-you-know… it’s a nearly perfect masterpeice!
Another might respond: “that’s ridiculous, instruments aren’t alive, that’s impossible.”
True, but neither are ribosomes, or signaling proteins, or sodium-potassium pumps, or ATP synthases… and yet…
The human body is exponentially, dare I say INFINITELY, more complex.
… I have much more to say, but I will wait and see if there are any rebuttals.
Let me just put a placeholder out here to say that I am working on a response. It's taking me a while, but it is forthcoming. This is an excellent discussion. The current statistical improbability of a Braves Wild Card win may allow me some additional time to work on it now.
@Blands,
If you know so many and they are so renowned, ask them why none of them or any of their colleagues have ever published a real scholarly, peer-reviewed article supporting Intelligent Design.
With the hypothesis question, I was really looking for someone to word the core hypothesis of the IC argument. I think I can do it for you: "There are some complex structures which cannot be explained by evolution." Yeah, I know it's more technical, but again, none of us are scientists and it won't do us any good to just mimic scientific arguments we know nothing about.
First of all, that isn't really a hypothesis at all. It isn't testable. You can't find support for it. But in any case, it sort of functions as a negative hypothesis. It is destroyed the moment evolution comes up with a reasonable explanation for the evolution.
I might make the claim that there is "no such thing as a person with three nipples!" But as soon as you show me one, my quasi-hypothesis is ruined. I can't really go out and run experiments showing how everyone I know has two and conclude that the original statement is correct.
The evolution of the eye is another, more specific negative hypothesis. Just for one example that is pretty easy to follow, watch this:
http://www.pbs.org/wgbh/evolution/library/01/1/l_011_01.html
All of the rest of your arguments are just fallacies. The orchestra, the trumpet... Yes, I am pretty sure that all of the scientists who study this kind of thing are aware of the complexity involved (much much more than any of us who can't even pronounce the things they are discovering).
I have another, completely different approach that I think you really should consider. I don't expect anybody to be convinced by arguments from the outside.
Read The Language of God by Francis Collins. Collins is a Christian and was the head of the Human Genome Project. He is extremely qualified to speak on this kind of thing.
His book discusses how Young Earth Creationism and Intelligent Design is not only bogus science, it is dangerous to Christianity. The phrase he uses a lot is "the God of the gaps." Throughout history, many people have believed in the God of the gaps. That means that whenever a question has not yet been answered by science, they proclaim that it must have been God, had to have been God, and couldn't have been anything other than God. Then they get egg on their face when scientific explanations come along. For people who believe in the God of the gaps, their God is constantly shrinking.
Collins would say - and so would i - if you are going to believe in God, don't put him in such tiny places as the gaps. You have to expect that most of these gaps are going to be filled eventually, so it is shrinking real estate. Besides that, why shouldn't God be able to co-exist with scientific explanations?
Collins talks about that, and he is definitely worth reading.
This also goes back to the mutually exclusive discussion above. If you believe that God and science are mutually exclusive ways of explaining natural phenomenon, then God has been losing for hundreds of years. God hasn't gained any territory at all. In the ancient world, people attributed absolutely everything to supernatural forces. Now, we have scientific explanations, theories, and equations for pretty much everything.
I have to thank you for posting this, because it has prompted me to read all kinds of stuff on the issue. PBS has the best library of understandable material, especially in video form. I highly recommend them.
I laughed out loud at something I read on an ID site earlier. It said that one of the reasons why ID articles aren't found in peer-reviewed journals is because of "new paradigm opposition." I almost spewed my Capn Crunch when I read that. New paradigm? That's like someone trying to replace the germ theory of infectious diseases with the "new" theory of the evil eye curse. There's nothing new about ID. It's what people believed before we had microscopes and genome projects and extensive fossil records.
John,
Consider your place held.
What’s up with those Braves, getting our hopes up only to dash them so cruelly?
I’m looking forward to a post from you outlining what the Braves need to do this offseason to be competitive all year next year.
I think we need to make a hard run at LaRoche—it’s been night and day since we picked him up, and seems to have rejuvenated him as well.
Justin,
Thanks for the comments.
I especially like your mention of the problem at “starting” at places other than nothing, and also pointing out the non-living nature of ribosomes, etc. I hadn’t considered that before.
David,
(1) This has nothing to do with our discussion, but it drives me crazy every time I see your name, so I’ll ask: how is your last name pronounced? Is it “Mains”, “Maniss” or something else?
If all I get out of this investment of time is the correct pronunciation of your name, that will be worth something.
(2) You’d have no way of knowing this, so I’ll just point it out, but Justin is a doctoral student in exercise science. His life revolves around studying the human body.
He wouldn’t claim to be a world-class expert on evolution or ID or IC (or probably anything else), but it’s a disservice to him to suggest that he’s as scientifically ignorant as a youth minister (me) or law student (you—right?).
I’m not saying, “He’s an expert so I win,” I’m just pointing out that he’s not out of his depth in any of this discussion.
(3) As far as the “Peer-Reviewed Issue” goes, well, this sort of goes back to one of my original points.
I don’t think anyone suggests that the scientific community as a whole supports ID or IC; my whole point is that they’re not open-minded enough to even consider it.
This is the main premise behind Ben Stein’s Expelled—the scientific community rejects ID out of hand, and ostracizes any scientists who suggest that it has merit.
Ironically, it reminds me of the Catholic Church back during the days of the Inquisition, Galileo, etc. Thankfully, ID proponents just lose their jobs and get made fun of rather than getting burned at the stake.
(4) As far as hypotheses…
In general, testing for intelligence is possible, because we do it all the time. If you’re walking on the beach and come across “David Manes” written in the sand, you don’t assume that the waves created that by some freak accident. Similarly, NASA monitors signals from space, searching for signs of intelligent life somewhere. There are criteria they apply to determine whether or not a signal shows signs of intelligence. I could go on and on, but you get the idea.
With IC specifically, let’s use the hypothesis you proposed. I’ll grant that it’s a “negative hypothesis”, but even then, it’s worth mentioning that, using your example, no one has yet come close to finding anything that resembles a third nipple.
But what about the primary hypothesis of evolution? Let’s use some of the language of Darwin himself: “All complex systems we observe are formed by numerous, successive slight modifications, which are entirely accounted for by natural selection.”
If this hypothesis were readily testable, evolution could’ve been proved or disproved long ago. Instead, scientists just present example after example of natural selection in a microevolutionary sort of way, which proves nothing.
This goes back to an earlier point I was trying to make, which is that when it comes to evolution, scientists don’t follow their own rules, the same rules they try to impose on ID.
(5) Haven’t read the Collins book. Sounds interesting, and I’ll certainly look into it.
I guess I don’t really feel like I’m “gapping” God though—I believe that He’s the Designer of everything that is, and as science unveils more and more of the systems and laws He’s enacted to govern His universe, I’m constantly impressed by how big He is.
(6) I’ll agree with you that there’s some disingenuity about presenting ID as “new”—that’s just marketing. People have believed in a Designer for a long time. ID is more like an old product with new features in new packaging.
IC would be an example of one of these new features.
1. It's "MAY-ness" Yeah, I am a law student. That isn't relevant here except to maybe show that I like to debate things (I do), I know how to research intelligently, and I am able to think critically.
2. That's fine. I am so ignorant that I don't even know what exercise science involves. I am sure that field comes into contact with biology more than mine does, though. The point isn't to disparage anyone who isn't a self-proclaimed amateur biologist (you and I both are, as are most people who discuss evolution and ID).
I think the really important thing to remember is that we can have an interesting discussion about the debate from the outside without resorting to recreating the debate. I think we can do better than just restate the arguments from each side - I think we can talk about what they mean from the outside.
3. I haven't had a chance to see Stein's movie yet, but I am not sympathetic to his views. I am sympathetic to the average person who chooses to believe in a God who created the world and disregard the scientific consensus on evolution. But I have little sympathy for trained scientists (few though they are) who try to put forward their personal faith convictions as science. In short, ID could possibly be defended as a personal opinion, but it does not conform to the scientific method and cannot challenge an established scientific theory. It just doesn't exist in the same world as real science.
More to the point of this original post, IC is a philosophical argument more than it is a testable hypothesis.
4. Those "tests for intelligence" that you cite don't seem to relate here. Finding writing in the sand or intercepting beams from space can only be attributable to intelligence if no other explanation is given. For each of the supposed "signs of intelligence" put forward as examples of IC, there are reasonable explanations given that frankly make a lot more sense than assuming intelligence.
If we get in the habit of disregarding scientific theories and evidence to explain phenomena simply because the phenomena and the explanations are complex, we may as well throw out most of modern science. It would be much easier to just assume an intelligent God is responsible for hurricanes. Meteorology is far too complex. Wouldn't it be easier to disregard the study of air pressure and ocean temperature and jet streams and who knows what else? It would be easy to just say God did it?
Let's talk more about nipples.
With my initial analogy, I said the IC hypothesis is something like "no reasonable natural explanation can be given; therefore it must involve a supernatural explanation." In the nipple analogy, the third nipple is the explanation. Countless scientists have put forward explanations of the IC examples. In my brief research over the past few days, I watched lots of PBS videos and read lots of articles about the evolution of the eye and flagellum. Each example given is a nipple. There are tons of third nipples out there.
You try to re-cast the nipple analogy to say that the nipple is not the explanation, but the thing itself. Fine. But then the IC/nipple hypothesis would have to be worded like this: "there is no biological explanation for how a third nipple could develop; any third nipples in existence must have been intelligently designed." I am no nipple expert, but I don't think it would be very hard for the experts to demonstrate with theories and models and experimentation that spontaneous tri-nippleness could occur.
5. The gap isn't an overt gap, it is an inadvertent gap. The people who believe in the God of the gaps are, of course, among the most pious in the country. But when they stake out unexplored intellectual territory and say that it could never be explored or explained because only God explains it, then they are setting their God up to be defeated eventually. It's happened before and it continues to happen.
You have to believe in a God who doesn't mind that human biology, geology, and physics have advanced to the point where we can explain almost everything in the natural world that ancient people (like the biblical authors) attributed to supernatural forces. If God is really proprietary about that kind of explanation, he must be very mad by now.
6. I'm glad we don't have to argue that point. What does that point mean to you, though? To the scientific community, this not-new "theory" of ID is asking tens of thousands of scientists to disregard the advances that have been made over the past hundred years or so and go back to the way people used to think before all this knew knowledge was uncovered. That's a pretty big request. It's no wonder why the ID movement isn't gaining any traction outside of non-scientists.
7. One new thing. You mentioned earlier something to the effect that you are a young-earth creationist (YEC). So like, the Earth is 6,000 years old and dinosaurs were on the ark with Noah? Again, I don't think debating that actual debate would be that interesting. But here is an interesting part of it.
I think the only way that a person arrives at YEC is by starting with the modern English translation of the Bible as the revelation of ultimate truth. Although I find that starting point immensely disturbing for a lot of reasons, let's set it aside for a moment.
Science is about starting with the evidence, setting aside presuppositions that demand certain outcomes.
If a group of scientists lived somewhere where they had never heard of the Bible, but they had access to all kinds of scientific information about geology, astronomy, physics, and biology, there is no way they would conclude that the world is 6,000 years old. The evidence does not lead to that point.
On this basis alone, the ID movement fails to meet the definition of science. Although its spokespeople assert that the evidence leads to their position, the reality is that only evangelical Christians seem to be drawn to ID at all. The only way you arrive at the kinds of conclusions that YEC and ID and IC have to offer is by starting with the Bible, and that is not scientific.
First of all, Luke, I appreciate your willingness to thoughtfully consider these arguments and take time to respond. It's sometimes tough to get that far, even with people who adamantly believe something, and you're to be commended for your work, not only on this topic, but on many others as well. David has already covered some of the ground I was planning to cover (although I might not come to some of his same conclusions), but since I'd already prepared most of this, I'm going to post it all anyway. Hopefully I'll have a Braves post up like what you suggested on my blog in the coming weeks. I'm with you on LaRoche, even though his first-half splits scare me.
There's a veritable ton of posting material here, and it's all worth a response. I plan to tackle as much as possible in this attempt, and I'll second (third?) the disclaimer that I'm not a scientist, and I don't have all the answers. I'm also not studying science and haven't taken a science course since AP Physics in high school, so you're free to take it all with a grain of salt. This is just my synthesis of what I've come to believe over the years, punctuated by some more detailed research over the last week or two. I also appreciate what David said about not needing to cover all the arguments again, but I suppose I'm going to give in and do it anyway. My responses will be spread across several comments.
I'm not really sure where to start, so let me first answer your four questions you presented in your first batch of comments:
(1) I do reject ID as "science." I'll explain what I mean by that shortly, but you raise a good point in (3) about how we define science. I believe in a Designer, namely God, as a matter of "religion" or faith. I suppose this would also answer question 4.
(2) I support ID, but not in the way it is typically presented, as science. My faith leads me to believe in ID (but not necessarily its proponents' arguments) even though it has not been proven scientifically. I'm not sure exactly what you'd call that: either some form of old-earth creationism or theistic evolution. I understand that a large number of creationists wouldn't call the latter explanation "creationism," so I guess that's kind of a hedge answer.
(3) Accounting for my answer about ID in question 2, yes, I support ID but reject IC.
On to your prior points (numbers refer to the first group of posts, not the more recent exchange):
In point (1), you acknowledge that IC is rejected by the scientific community as a whole. I would not go so far as to say that the scientific consensus is always right, but I would want to see some compelling evidence otherwise if I were to dispute the scientific consensus, at least when it comes to observable phenomena. Having read about the content of Expelled, I think I probably have a similar opinion of Stein's work, although he's a brilliant man. The complaints about the scientific establishment not being open to ID "science" amount to little more than whining because the ID group, for the most part, doesn't attempt to use the scientific method. Specifically, I still don't think irreducible complexity holds up scientifically, and I'll attempt to show that a little more clearly now as a response to point (2).
Response to (2) on IC and "co-option":
First let's spell out Behe's "evolutionary definition" of IC: "An irreducibly complex evolutionary pathway is one that contains one or more unselected steps (that is, one or more necessary-but-unselected mutations). The degree of irreducible complexity is the number of unselected steps in the pathway."
It's tempting to point to examples like the flagellum and say that the best evolutionary explanation is 40 proteins short of reaching functionality. This was the case in the past, but it is no longer, as scientists like N.J. Matzke (http://www.talkdesign.org/faqs/flagellum.html) have sought to work through the evolutionary origins of the flagellum. Other IC test cases (the eye, the human immune system) have received similar treatment, and these prominent IC examples should no longer be considered "irreducibly complex."
I think the orchestra example presented by Justin is simply a straw man. The tone of that argument implies either (or both) that the probability of evolution getting us to where we are now is impossibly slim or that it's not possible for selection to have resulted in new species (macroevolution). I'll get to the former probability-based argument in a response to (3) and the latter argument later in my response to (4). For now, I'll just say that neither is true. (Justin, if you are familiar with evolutionary biologists who are conceding either of those two points and still arguing in favor of evolution, I'd like to see it as well. I get the impression that the example was mostly for effect, though.)
Anyhow, to say that certain systems are irreducible is not a scientific exercise. It's essentially pointing at something in nature and saying: "Here, evolutionary biology, prove that this could have come from your theory!" It's not wrong to do so, but it doesn't really serve any kind of scientific purpose.
The logical steps required to support IC seem to be as follows for any particular example:
1. Demonstrate that a particular system has a function that would not be possible if some of the pieces were removed.
2. Suggest that we don't currently know any functions for these pieces outside the process.
3. Since we don't know that these functions exist, assume it must be unexplainable.
4. [The ID Step] Because it is unexplainable based on what we know, an intelligent being must have created it.
Scientists have repeatedly "reduced" these once seemingly irreducible complexities and shown that they fit within the evolutionary framework. The formerly-unexplained complexities are continually crumbling. IC advocates can ostensibly point at something, anything, and say "prove it," but saying something is currently unproven isn't the same as proving it false. Step #3 above is an unscientific, untestable assumption. (I'll get to testability next.) Perhaps these system complexities seem unlikely without having explored them, but it doesn't change the fact that they happened. There are enough examples of evolution at work that most scientists have come to this conclusion and aptly labeled IC as pseudo-science. It's not because they have reasonable doubts and are somehow being oppressed by some sort of academic bias against creation. (I'm not on the inside, for sure, but that's my evaluation.)
Again, I'll re-emphasize that I'm not doubting an intelligent designer at all. I just don't think it can be proven scientifically, at least not based on what we know today.
Faith/Religion and Science, or a response to (3):
As I said in the previous comment, I don't think intelligent design can be proven scientifically based on what we know today. This would probably be a good opportunity to explain the distinction to which I previously eluded regarding science and religion.
Some critics of evolution (and advocates of forms of creation science/ID) argue that evolution is based on a materialistic, naturalistic world view, and that intelligent design is actually more scientific because it accounts for other explanations other than naturalism. This flies in the face of the scientific method, which requires testable hypotheses. David was getting at this as well. Major tenets of evolution can be tested and supported by science, while creation science/ID currently cannot. Proponents of creation science/ID would tend to argue for redefining the bounds of science to include "non-naturalistic" theories, but this would so radically redefine science that it would not resemble science at all.
You're correct to say that we've, over the course of history, decided that an "outside actor" has no place in science. I think this is a flawed reasoning as well to some degree (since I believe in a Designer), but I don't think the answer is to introduce an untestable piece into modern science and simply say, "if you can't explain it, it must be God (or just an 'intelligent designer')." That is, unless you're going to show how we can scientifically test theories that include a supernatural explanation, in which case you've probably made a major breakthrough. I see no conflict in letting faith take over for me where modern science, including evolution, ends.
Your synthesis of non-ID and ID arguments is solid, although it leaves out the scientific explanation for evolution in the non-ID approach. Scientists don't simply believe "it must have happened;" rather, they have presented the evolutionary framework for evaluating why they happened and supported that framework with countless examples.
Part of your argument for (3) hinges on the supposed statistical improbability of evolution. As with IC, this argument is essentially another "argument from ignorance" and can be debunked scientifically. I'll provide a short explanation here.
You've undoubtedly heard something along the lines of the "watchmaker analogy," which posits that a watch is analogous to creation in that it is complex and ordered (rather than random), and thus statistically improbable. Of course, with a watch, there was a watchmaker (intelligent designer) to put it all together. To say that Earth had a "watchmaker" is then an argument from ignorance because it takes a seemingly unreasonable conclusion (that it just happened) and presents the opposite as the only reasonable explanation (something intelligent must have designed it). It's simply a fallacious non-scientific argument.
Parts of evolution involve random elements, like the soot in the black moth example you mentioned, but evolution itself is not derived from chance. Selection is not a random occurrence, and evolution follows an ordered trajectory based on such concepts. I think the probability argument is really directed toward abiogenesis, which is not the same concept as evolutionary biology, but instead is a popular explanation for how Earth began from inanimate matter. I'm not advocating for abiogenesis.
The last sentence of (3) is false. Evolution is quite certainly human theory, but at least in terms of its major tenets, it is also quite certainly proven. Natural sciences are not "proven" in the same way as mathematics and logic. Rather they are validated through tests and compelling scientific evidence. These scientific "facts" are formed into theories which are not simply conjecture, as we might think when we hear the word 'theory.' A scientific theory is still something testable and reaches a higher standard than a simple opinion. That's just to clarify some terminology that's frequently misused.
(continued)
There are in fact ways that evolution can be tested. It's a concept called falsifiability, and a statement is considered falsifiable if a particular observation or test could prove it false. This is not the case for IC, but it is for evolution. If anyone were to observe a static fossil record or the supernatural creation of an organism, that would completely falsify evolution.
A response to (4) with regard to Micro/Macro-evolution, speciation, and interpretations of God and the Creation:
No harm, no foul on the "liberal" moniker. I've worn that for a while now and will probably continue to do so. I don't really buy Dawkins' perspective, either.
Let's move on to the point you've made about macro- and micro-evolution. This is a distinction that is commonly used among ID supporters, but it really has no logical basis. There is no difference in the way that evolution works on a micro level, as with the moths compared to the way it works on a macro level, as it's really just a matter of scale. Macro-level evolution would usually be called speciation, or the formation of new species.
It is also untrue that speciation has not been observed. The Hawthorn fly is considered such an example of a new species being formed, and you may be familiar with the concept of transitional fossils, but most of the argument about speciation seems to be around the question: "how do we know it's a new species?" The underlying principles are actually the same regardless of how we define species, because the processes are one and the same between microevolution and macroevolution. The evolutionary biology behind both processes has indeed been proven, since they are only different in terms of scale, and ultimately there is no logical difference between the two.
Having said that, I don't think a larger-scale version of evolution is inherently conflicted with a belief in the Bible. I don't think my belief is unorthodox at all, nor do I "regularly disregard" Scripture to reach that conclusion. You'd probably guess that I don't believe in a literal interpretation of the creation account in Genesis. Perhaps you'd consider that "disregard" (I'm guessing that may be where we seem to differ the most, actually). We could probably open up a whole new discussion about that, but I don't think it's a big issue as far as evolution is concerned. Even as it relates to your point (a good one) about the uniqueness of man, I don't see anything particularly wrong with thinking that God gave our species a soul and a special role on this planet, even if other species appear to be close to "His image" from evolution's standpoint. I think God created a masterful framework that modern science continues to uncover.
As David said, opponents of evolution have set God up to fail over and over again and watched him do so using the logic they've provided. I think that's terribly unfortunate.
A brief response to (5) with regard to ID and Creationism, and Conclusions:
Lots of very smart men and women over thousands of years have come to the same conclusion you have with regard to Creationism, so I don't find it laughable even if I don't think it's correct. I understand the distinction between ID and Creationism, although ID itself is a fairly recent development in opposition to evolution. Like you said, it's an old product with new packaging. It's more of a marketing strategy to make the idea of God plausible when it otherwise might not be, and organizations like the Discovery Institute haven't hid that as their motivation.
Let me see if I can quickly summarize my perspective on some of the topics we've addressed, now that we've trudged through some of the specifics.
I personally believe in a designer, God, who created the universe. The universe operates in a way that men have sought to understand through science, which is a reasonable endeavor. Over the course of history, we have come to understand more and more of God's creation and the processes he put in place. Evolutionary biology is one of those processes and is not inherently at odds with the Bible, although I will admit that my interpretation of the creation account is not literal.
Irreducible complexity and some of the other common arguments against evolution suffer from logical fallacies and are not scientific at all. This presumes a definition of science that follows what has come to be known as the scientific method, which are based on testable hypotheses. The theory of evolution is based on testable hypotheses, and many of the arguments against it are not. Evolution represents the best explanation for the way God has chosen to order the world.
That's where I am right now.
Luke, excellent thoughts. I appreciate your perspective.
David, I will talk with my mentors/heroes of physiology at our next conference about the peer reviewed articles and get back to you … you will have to wait till May, sorry. My initial feelings are similar to what Luke as already brought up: they would be completely ostracized from the scientific community if they did.
You have a lot of thoughts and I definitely can see that you have spent quite a bit of time thinking and researching about your perspective. Well done.
Unfortunately, you cant win a debate or persuade individuals to listen to your side by just saying: “your arguments are fallacies” and then not point out how they are.
I will listen again to the scientific argument when someone can tell me:
1) how something (more accurately: EVERYTHING) came from nothing. Especially in the context of a universe that is moving toward chaos.
And
2) how non-living, non-intelligent structures form a living, intelligent being.
I was going to put quite a bit of effort into a response, but it will only be heard by those who agree with me … I guess that is how most debates are.
I respect Luke intensely because he is honestly interested in your beliefs and desires to learn more about where you are coming from.
I certainly do not put GOD in the gaps and neither do my mentors/heroes. I believe GOD CREATED all, not just the things that we don’t understand (which the amount we don’t understand is actually INCREASING… not decreasing). I plan to spend my life studying HOW GOD created the human body (specifically in the context of exercise).
If this (life) is an accident then there is no purpose. What a terrible way to live.
John,
Good thoughts. I didnt address any of them because I didnt refresh my browser when I entered my post. Sorry.
Justin,
I don't think you understand the context of the discussion here. Let me try to give some perspective. I am not here trying to make anybody see the logic of evolution. I am the one here trying to see where people like you are coming from. It continues to astound me how anyone can take the approach I outlined above in my (7) point. I am willing to hear explanations and see where you are coming from.
But if all you give me are personal heroes and logical fallacies, then there is no wonder that your position is the extreme minority among educated people in the world.
From several steps back, this is what the non-debate looks like:
1. Real science has spent a hundred years gathering evidence in the fossil record and genetic material that points toward common ancestry and gradual evolution. Numerous theories and experiments have appeared to take specific elements even further with computer models and whatnot. Real science made the paradigm shift to adopt evolution a long time ago because of all of this gathering evidence.
2. Instead of looking at that evidence and coming to the same conclusions that honest observers give, some evangelicals continue to rely on the non-scientific ancient book, the Bible. They use biblical literalism, an idea also invented in the past couple hundred years, to "prove" that YEC and ID are correct despite any rational evidence to the contrary.
3. ID proponents ask questions like "how does something come from nothing?" and "how do non-living, non-intelligent structures form a living, intelligent being?" You ask these questions as if they speak for themselves and have no answers. These are the same questions that have already been asked and answered at the very beginning of the discovery of evolution. More evidence is found for these questions all the time, but we are way beyond asking the question now. So when you ask those questions, I don't know what to say. Uh, go read something about evolution? Even a casual reading will explain how those things happened. Those are not impossibly complex questions, nor are they arguments that support your side at all, except to ignorant people who are predisposed to believe the simple over the complex.
I think you must realize how much you are in the minority. By you, I mean any educated person who still believes in ID. It's fine to be in a severe minority sometimes, but when you are, you bear the heavy burden of toppling the established paradigm. Paradigms have been toppled before, in science and other fields. But you have no hope of toppling it with the kinds of "arguments" you are using here.
The analogies aren't worth talking about and here is why: they are moronically simplistic and bear no resemblance to the actual debate. I can't even begin to deconstruct them. Furthermore, they aren't even original.
We could get into a war of analogies that each side makes up. How about this one: "Evolution deniers are like a person who walks up to a mountain and says 'I don't believe in that mountain.' A nearby person asks how the mountain could be denied. The first person claims 'not only do I not believe in that mountain, I bet that you can't even find me one pebble to show that the mountain exists.' The second person is dumbfounded and again, just points to the mountain, explaining that the entire thing is made of pebbles."
Does that analogy work? There is a mountain of evidence for evolution, yet some people walk up to it and deny the whole thing, right down to the very pebble.
No, it is a stupid analogy.
Analogies have very little place in scientific arguments because science is usually not simple enough to be described in a 2 or 3 sentence fable. If all we had were 2 or 3 sentence stories that normal people could understand, we could mock all sorts of theories. "Haha, did you hear the one about this supposed theory of 'lift?' People actually think they can fly, har har har." "Dur, I don't think I can believe that little tiny alive things are making me sick, I mean, I can't even see them." Anyone who is seriously going to engage a complex issue has to admit from the beginning that simplistic analogies are not going to be useful.
David,
I’ll respond to a few of your points here, and probably some more in my response to John, but it’s getting to the point where we’re just saying the same things over and over, so I feel like the useful discussion is winding down.
(1) It’s ironic to me that you explain in such detail how useless and irrelevant analogies are in this discussion after devoting so much time to your nipple metaphor.
But maybe you only spent so much time on it because, as you say, I “re-cast” it. If I did, that was inadvertent on my part. My bad.
My point was that the explanations that IC opponents have proposed for IC (like co-option), simply don’t adequately explain the situation.
In your original example, you said the “negative nipple hypotheis” would be discounted as soon as a person with three nipples was found. My contention is simply that the arguments against IC simply don’t constitute such a person.
(2) I am a Creationist, and I do tend to believe in a young earth, though due to factors like incomplete genealogical records, you could end up with a lot more than 6000 years.
I base that belief on a literal interpretation of the creation account in Genesis, although I am aware that many Christians do not take that portion of Genesis literally. I am more at home with Biblical interpretation than I am with scientific discussion, but even there I make mistakes.
So what I’m getting at is that while I would consider myself to be a YEC, I’m not dogmatic about it—it’s not central to my faith. Things that are central to my faith would be God as the Creator of the universe, Jesus as His Son, the resurrection of Jesus from the dead, etc.
You may not care about any of that, but I say it just to point out that my faith doesn’t hinge on IC—I consider it to be a compelling argument, but to use your terminology, I’m not cramming God into that “gap.”
On this same topic, you said, “The only way you arrive at the kinds of conclusions that YEC and ID and IC have to offer is by starting with the Bible, and that is not scientific.”
Again, I think you’re making the mistake of over-generalizing here. To come up with the specifics that YEC demands, certainly I think you have to start with the Bible. But as I’ve already pointed out, not all ID and IC proponents are evangelical Christians, and as I specifically pointed out, Behe himself firmly supported evolution until his own research and observations pointed him toward ID in generally, and IC specifically. He wasn’t going out “looking to prove” the Bible.
There are other scientists with similar stories. Certainly their are Christian scientists who enter the field looking to find support for what they believe, but that’s not what all IDers have done. In the same way, certainly their are atheist scientists who enter the field looking to find support for what they (don’t) believe, but that’s not what all of them have done either.
(3) In addressing Justin’s earlier questions (how could something come from nothing, how could intelligent life come from unintelligent non-life), you said, “Even a casual reading [about evolution] will explain how those things happened.”
I’m sorry, but that’s just not true. If evolution could casually explain these ways in a convincing fashion, then you and I wouldn’t be having this discussion because I’ve read plenty casual descriptions of evolution.
Instead what you have is the infamous and comical of example of Dawkins being pushed by Stein in an interview to provide the answer to the beginning of life on our planet and him saying that he didn’t know, but maybe it could have been “seeded” by intelligent aliens from another galaxy, although those aliens themselves couldn’t have been intelligently designed.
Statements like that are part of the reason why a lot of reasonable people, myself included, don’t consider evolution to provide convincing answers to some important questions.
John,
I appreciate your comments as well as the time you took in preparing them. I won’t respond to every specific thing you’ve said, but I’ll try to hit the major points. Some of this has already been addressed (at least indirectly) anyway.
I also appreciate your attempt to refer back to my original numbers—it now occurs to me how confusing it is to number arguments when more than two people are involved. I’ll use bold text for the sake of organization and hopefully it will be clear what part of your comments I’m responding to.
“Scientific Consensus”:
Certainly I get your point here: when you have a vast majority opinion on something, they aren’t always right, but they very often are.
But, as you admitted, there are exceptions. For example, it was once the scientific consensus (or at least, the medical scientific consensus) that bleeding someone was a splendid medical treatment in a lot of situations. We now know that to not be the case (I would suggest that the current firestorm over Global Warming might be another, more modern case, except that I already have enough worms crawling around the comment section of this post without opening another can of them!).
This example doesn’t prove anything, other than to point out what you already know, which is that the scientific consensus isn’t always right. This is probably an area where Justin could actually provide many examples of how the scientific consensus has been completely wrong about the way the body has worked in the past, but that isn’t necessary either because I accept your point: the scientific consensus is usually right—I just don’t it is in this case.
Irreducible Complexity as a specific argument:
I don’t know much about the other examples, but I’ve read quite a bit about the flagella, and in that case (and I know that I’m repeating myself), co-option just doesn’t seem to account for all the problems that IC brings up.
I don’t know much about the eye at all, but Justin seems to have a much better grasp on that issue than I do, he understands science better than I do, and he thinks that IC still applies. I’m not saying, “Anything Justin believes is good enough for me,” but I do have tremendous respect for his knowledge and insight on scientific matters, and as he indicated before, people tend to only hear arguments they agree with. My point is that I’m not trying to be closed-minded, and I admit to not knowing much about the eye (except that mine are tired from reading and typing so much), but proponents of IC don’t think that the eye shatters their case in any way, so I probably wouldn’t either.
Conclusion: from what I know about Irreducible Complexity, it seems like a compelling argument to me, and the arguments against it which I have heard don’t adequately answer the problems it poses.
Intelligent Design as inherently “unscientific”:
I get this criticism, I really do, and considering the way that “science” is defined, I agree with you. I also agree with you in that I believe in a Creator because of faith, not because science tells me so. I do believe that science lends credence to that faith, but certainly many believers (and maybe IDers too, I don’t know), overstate that by saying you can prove God through science, or anything else. After all, if you had proof, that doesn’t leave much room for faith, and God asks us to believe in Him, not to prove Him.
What I take issue with is the way that many people use “scientific” and “advanced” as perfect synonyms, and then use that to imply that ID, or more specifically IC, are merely forms of backward superstition like the “Evil eye theory” that David referred to.
A lot of the arguments that ID proponents are making today are possible only through advanced technology, and in the case of IC, at the sub-cellular level. It’s not like a bunch of yokels who dropped out of high school are cooking this stuff up; these are well-educated, experienced scientists, some of whom were incredibly well-respected before joining the ID “side”. It’s easy to just write them off as “unscientific”, but I think that’s a disservice to them.
I’m not really suggesting that you’re guilty of using “scientific” in this sense, but it happens all the time, and I don’t think it’s helpful to the debate.
Abiogenesis vs. Evolutionary Biology:
You’re right, pretty early on in this discussion, evolutionary biology and abiogenesis got thrown in together. I realized this, but didn’t really try to correct it because I think for the most part, people believe in them as companion theories—if you believe in one, you believe in the other.
I could be wrong, but I’d suggest that you’re probably in the significant minority of people who accept evolutionary biology but reject abiogenesis. I (obviously) have problems with both, but many (most?) IDers would fall where you do on that spectrum, I think, which was part of the reason why I took the time to try to distinguish between ID and Creationism.
Microevolution, Speciation, etc.:
I appreciate you bringing up the Hawthorn fly—I’ve done some reading about it and it’s helped me to better define my thinking.
The Hawthorn fly fits into what I already believe, but I was guilty of an imprecision in terms in my last round of comments.
There does seem to be some debate about what constitutes a “new” species, in this case and in others. From what I read, there is little interbreeding between the “new” species of Hawthorn fly and the old, (which some use as mark for a new species) but really, this isn’t anything previously unseen—Great Danes and Chihuahuas can’t mate with each other (at least, not naturally), and they’re still considered to be of the same species.
Keeping with the examples of the dogs, this does show how years and years of breeding (in the dog case, intentionally breeding for traits, but it wouldn’t have to be so), results in a wide variety of dogs.
But like I said, this fits into what I already believe—although I believe that God is the Creator and Designer of life, I don’t think He created every specific variation of life that exists today at Creation—I think He created “base models” of different types of animals. For example, there are many different species or subspecies of giant tortoises today, but I think originally, God just created a general tortoise. Same thing with the dog example.
My point with all this is that I see a difference between these types of changes, and the wider scale changes that evolution insists on. So now we have a new fly that only eats apples and doesn’t mate with the other flies—great, but it’s still a fly, and to you or me probably looks a lot like any other fly. Show me a fly that then becomes a beetle, which then becomes a crab, etc., and then we’ll talk.
I realize how ridiculous that sounds from your point of view. After all, we’re really talking about the same process at work, it’s just a question of scale—but on the grander scale, it just hasn’t been observed, and I would contend that it isn’t observable.
Final Thoughts
My views are probably pretty clear by now, but to briefly sum up:
I believe that God created the world as described in Genesis. I believe He endowed living organisms with remarkable abilities to adapt and change, which leads to a wide variety of life on our planet.
While I don’t believe that it is possible to prove the existence of a Designer, I don’t think ID is without evidence, and I think IC is one such piece of evidence.
Basically from what I can tell, you believe Genesis to be a non-literal account of Creation, and evolution to be a method that God uses as part of His creation and governance of the universe. I disagree with that, but I understand where you’re coming from and respect your viewpoint. It leads me to some other questions about what you believe, but I’ll table that for now and, if you’re willing, might follow up with you in the future.
I appreciate your comments, and especially the tone you bring to the discussion. It’s always a pleasure to disagree with you, even though I still the Braves were pretty shady in their dealings with Smoltz (his poor performance this season aside).
Luke,
Excellent thoughts once again. Your desire to keep arguments civil is one of the reasons I keep coming back to debate some of these issues. Unlike some places and people, I feel like you're willing to consider both sides.
Your point about scientific consensus is certainly true. The prevailing scientific thought has been comically wrong on a number of things in the past. I think evolution is the best framework for evaluating modern biology, but that could change if the evidence begins to show otherwise.
With regard to IC, I still don't think that evidence is compelling, and I would still contend that IC is logically fallacious as a scientific theory.
I see what you're saying about the "advanced"/"science" lack of distinction. Certainly there's an "advanced" element to what IC proponents are contending. I don't think it's right, or that it even fits into a scientific framework, but there's no point being condescending toward ID as a matter of intelligence, especially people who are devoting their lives to studying such things.
Perhaps I am in the minority when it comes to believing in evolution but not abiogenesis. A popularly-cited 1997 Gallup poll asked both the public and scientists about where they fall among three choices:
Belief in YEC:
Public 44%, Scientists 5%
Belief in God-guided evolution:
Public 39%, Scientists 40%
Belief in evolution without God:
Public 10%, Scientists 55%
That's not to say that 40% of scientists doubt abiogenesis, but it may not be terribly uncommon. Surely some of them believe abiogenesis fits into their idea of God, although I remain skeptical about it.
On microevolution and speciation, I think it's probably also a matter of scale when you're determining where to draw the line for a new species. I don't have an answer, although I do think there's no fundamental difference between macro- and micro-evolution.
I won't say I'm unwilling to open up the debate about my interpretation of Genesis, but I don't think I'm ready to branch off in that direction right now. It's certainly a topic worth exploring in the future.
Having a minority viewpoint in the CoC certainly makes things exciting, but it's often tough to debate because a lot of people aren't willing to even consider another side to the argument. Everyone here has given me plenty to think about on this topic, and I'm grateful for the tone of the discussion as well.
I'm coming into this conversation very late, but I'll first mention: way to go, Luke, for staking out a realm of calm, polite discussion on the Internet, which so often seems degraded by anonymous animosity.
I won't get too into the overarching arguments here, but instead discuss one example that was brought up, as illustrative of the larger argument. The eye. It's always struck me that the human eye in fact demonstrates the shortcomings of the IC argument, rather than strengthening it.
My observation, which I don't think has been mentioned here, is that the "design" of the human eye possesses a couple of glaring inefficiencies that run counter to the idea that it was designed and appeared fully formed (rather than evolving through natural selection). Chief of these is the blind spot, which is located where the optic nerve exits the eye through the retina, leaving an area with no light-detecting cells. This blind spot occurs in all vertebrates, but not in the eyes of cephalopods, which developed similar-functioning, but differently structured light-sensing organs. The octopus has no blind spot; human beings do. (The octopus can also see the polarization of light! Which is cool, but I digress...)
Now, the human eye does have advantages over the octopus eye (the ability to change focal distances, for example), but the point is that neither eye is an ideal seeing apparatus. Both are snapshots in a dynamic process and differently flawed: the products of an accrual of micro-accidents that just happened to work and survive in a specific environment. Somewhere around the branching off of vertebrates in the evolutionary tree, an inefficient but functional mutation occurred, and the following generations maintained the inefficiency, building further mutations on top of it, resulting in all vertebrates having holes in their retinas.
Thus not only is the complexity of the eye reducible (as I think others in this thread have noted), its particular and inefficient complexity is an elegant illustration of how the processes of evolution can be discerned in present-tense, without observing the process is action. I think this holds whether or not one ascribes to the process a first mover or creator.
Anyway, just felt compelled to chime in.
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