Hitchens : Luskin :: Lion : Mouse

| 69 Comments

Christopher Hitchens was impressed by the existence of blind cave organisms, and wrote that they argue against a linear progression in evolution. He's quite right; creationism doesn't explain why their god tossed in to salamanders and fish a collection of complex developmental mechanisms that the animals simply throw away and do not use. Evolution does — descent from a sighted ancestor explains how blind cave animals can still possess the machinery for a lost organ.

Do you think the Discovery Institute would let this challenge pass by? Of course not. They put their top man on the job, so Casey Luskin wrote a rebuttal. After a long weekend and before a busy day of work, it always makes me happy to find a new Luskin screed — they're so dang easy to shred. Here's his devastating critique:

Hitchens, Dawkins and Carroll can have all the evidence they want that the neo-Darwinian mechanism can mess things up, turn genes off, and cause "loss-of-function." No one on any side of this debate doubts that random mutations are quite good at destroying complex features. Us folks on the ID side suspect that random mutation and natural selection aren’t good at doing very much more than that. And the constant citations by Darwinists of "loss of function" examples as alleged refutations of ID only strengthens our argument.

The claim that evolution can't create new features is one of the oldest and most tired fables in the creationist playbook — note that that link cites the Watchtower Bible and Tract Society and Henry Morris. It's false. In this case, their superficial knowledge also trips them up. The loss of eyes seems like a clear-cut case of degeneration…but when you look deeper, it's not.

The best studied case is the comparison of blind and sighted forms of Astyanax, a fish that has species that live in surface waters and have eyes, and others that live in caves and have lost them.

astyanax.jpg

The Jeffery lab has worked out the molecular details of eye loss, and it isn't as simple as messing things up, turning genes off, and causing loss-of-function mutations. To the contrary, all the genes for eyes are there and functional in the blind species. Simply transplanting small bits of organizing tissue from species with eyes to embryos of the blind forms can recruit host tissue to build a complete functional eye — that tells you the genes are still there. A comparison of gene expression patterns between the two also reveals that the blind species actually upregulates a majority of its developmental genes. Contrary to what Luskin claims, this is a positive change in development, not a loss, but an active suppression of eye expression.

What's actually going on is that there is an increased expression of a gene called Sonic hedgehog, which causes an expansion of jaw tissue, including both the bones of the jaw and the array of sensory structures on the ventral surface — this is an adaptation that produces stronger jaws and more sensitive skin, what the fish finds useful when rooting about in the dark at the bottom of underground rivers to find food. The expansion of Shh has a side effect of inhibiting expression of another gene, Pax-6, which is the master regulator of eye development. Loss of eyes is a harmless (if you're living in the dark) consequence of selection for better tactile reception.

Pathetic, isn't it, how abysmally wrong Luskin can be? His conclusion is even sillier.

Meanwhile, ID proponents seek to explain a far more interesting aspect of biological history: the origin of new complex biological features. Despite his quotation of Michael Shermer on the evolution of the eye, Hitchens has yet to do that.

Actually, despite claiming that ID proponents are trying to explain the origin of biological features, Luskin hasn't used this opportunity to even try. He can't; "Designer did it" is not an explanation.

69 Comments

Thank you PZ ^_^

Even if Luskin were correct and this did represent nothing more that a degradation, it would still be indisputable evidence for common descent. The only way he can deal with that is to move the goal posts and demand that it be evidence for the origin of the vertebrate eye. Of course it never was that, but who cares about logic when there are people to fool?

Once again, the might Casey has struck out.

Oh dear, picking on Casey Luskin, sigh, how tiresome. The only way he’s ever surprised me is from the fact that I’ve never been able to underestimate him: No matter how dull I expect his arguments to be, they are always duller than that. At least Bill “The Joker” Dembski comes up with something surprising every now and then – if never in a good sort of way.

Oh yes, Mr. Luskin, ID has the explanation for the origin of the eye: “There is no explanation, give up trying to find one, it just magically happened in some unexplained and unexplainable way.” It’s dull to even bother to complain about this.

Casey Luskin: the Jethro Bodine of Darwin-Bashers.

White Rabbit (Greg Goebel) http://www.vectorsite.net/tadarwin.html

With both the Hitchens’ article and now with this new one I’m surprised no one has brought up Darwin’s original observation about blind cave species. Paraphrasing; if species were designed then you’d expect that cave-dwelling species would be the same/related all over the world, because caves are similar environments and so demand similar designs. But cave-dwelling species on different continents aren’t similar. On each continent you find species similar to the local species on the surface and unrelated to cave-dwelling species on other continents. This is exactly what you would expect from common descent - where species migrate locally into the caves - but makes no sense whatsoever under a model of intelligent, separate creation.

Luskin Said: ID proponents seek to explain.…

I am continually amazed at how often ID fellows will say the evidence is coming, or the research is coming, the explanation, the new ideas, the revolution. But once again they sit in their arm chairs and think up arguments against science. Luskin probably makes more than I do, so he has got a sweet deal fooling the rubes. I couldn’t make a living lying to people, pathetic aren’t I?

What an amazing case! I had not seen the details of the development of these fish, and am all the more amazed. I too would have imagined it a mere “loss”. Fortunately, there are intelligent people who go beyond such assumptions to find interesting scientific facts. If only individuals like Luskin also had productive research to point to, someone might pay them some attention.

Every time. They sneer down at some ‘messed-ed up’, ‘defective’, organism of ‘mere biology’, and when I look up how it works, I’m filled with a sense of awe and reverence that I never got in their churches.

Dear Eric,

This is an excellent observation:

Eric said:

With both the Hitchens’ article and now with this new one I’m surprised no one has brought up Darwin’s original observation about blind cave species. Paraphrasing; if species were designed then you’d expect that cave-dwelling species would be the same/related all over the world, because caves are similar environments and so demand similar designs. But cave-dwelling species on different continents aren’t similar. On each continent you find species similar to the local species on the surface and unrelated to cave-dwelling species on other continents. This is exactly what you would expect from common descent - where species migrate locally into the caves - but makes no sense whatsoever under a model of intelligent, separate creation.

What Luskin and the rest of his pathetic band of Discovery Institute mendacious intellectual pornographers forget is the importance of common descent (well, maybe Behe does acknowledge it in his own peculiar way), not “design” as the key factor that’s relevant to the evolution of blind cave-dwelling species.

Appreciatively yours,

John

Vancomycin is an antibiotic that interferes with bacterial cell wall synthesis by binding to a D-alanine/D-alanine sequence that must react to cross-link the peptidoglycan of the cell wall, thereby strengthening the cell wall. In the case of vancomycin resistance, the bacteria have a mutated gene that controls non-ribosomal peptide synthesis, and instead of inserting a D-alanine in its cell wall, the NEW gene (not a broken gene) now inserts a lactate in its place. The lactate can no longer form a key hydrogen bond with vancomycin because of the D-alanine to lactate change, and the bacteria becomes resistant to the drug. This is a perfect example of a gene mutating to introduce NEW INFORMATION into the genome of an organism, information that allows survival in the presence of vancomycin.

PZ,

Funnily enough, Hopi Hoekstra and Jerry Coyne actually make a similar argument to Luskin. From the conclusion of their critique of evo-devo:

And, in contrast to the evidence for structural change, all three of the most widely cited cases have not yet produced definitive evidence that cis-regulation is involved. Moreover, these three cases focus on losses of traits rather than the origin of new traits, and in only one of the three (loss of pelvic structures in stickleback fish) is there a clear adaptive explanation for the trait loss.

http://pondside.uchicago.edu/cluste[…]e%202007.pdf

“a gene called Sonic hedgehog”

Is that really the name of the gene, that’s hilarious? Was it named for the Sonic the Hedgehog game, or was the game named for the gene?

the gene was named for the video game character

There was actually a related gene named hedgehog due to something with the appearance of the fly, so the student had to name this one sonic hedgehog. Early 90’s.

John Kwok Wrote:

What Luskin and the rest of his pathetic band of Discovery Institute mendacious intellectual pornographers forget is the importance of common descent (well, maybe Behe does acknowledge it in his own peculiar way)…

I know I’m in the minority on this, but I think that all the major DI folk, including the “token YEC” Paul Nelson, privately know that common descent is a “done deal.” IOW, even if some of them believe otherwise “on faith” (Omphalos creationists), they all know darn well that the evidence overwhelmingly supports CD, and a 3-4 billion year history of life.

I think that Behe admitted common descent years ago because (1) he is (or was) less politically savvy than most other DI spin artists, and/or (2) as a biochemist he knew that to pretend otherwise is as absurd as defending a flat-earth. But the DI needs the support of rank and file YECs and OECs, so they either play dumb about CD or vaguely doubt it (or pretend to). Even Behe, much later, added the pathetic disclaimer that there are DI folk who apparently doubt CD but are more familiar with the relevant science than he is. Of course he mentioned no names.

More importantly, when DI folk do vaguely argue against common descent, it’s always as a false dichotomy with design. And worse, they mine the literature for discussions of evolution for which a hasty read seems to agree with the false dichotomy. In reality, whether a designer is ultimately responsible or not has no bearing on whether the changes occurred in-vivo or required new origin-of-life events. There’s a strategic reason to play the bait-and-switch, though. That’s because there is a testable explanation – one that keeps passing the tests – for the in-vivo process, but none for an “in-vitro” alternative, though brave souls like Schwabe and Senapathy tried. And because most people do not understand that testable explanations are always incomplete (every confirmation adds another “gap”), whereas the increasingly vague non-explanations of ID are “complete” in the sense that they free the reader to infer whatever alternative he wants, oblivious to its “complete” lack of supporting evidence.

Whatever happened to Billy “The Kidder” Dembski? I used to see snippets about him all over science blogs and here at PT, but now we never hear of him.

Has he gone underground, died of embarrassment, or finally become as irrelevant as he was always threatening to do?

iml8 said:Oh yes, Mr. Luskin, ID has the explanation for the origin of the eye: “There is no explanation, give up trying to find one, it just magically happened in some unexplained and unexplainable way.” It’s dull to even bother to complain about this.

Actually I think this is a much rarer form of anti-evolution criticism: a specific claim about an observed natural feature where it is said (by the anti-evolutionist) that it -IS- due to mutation, but that the mutation only caused a loss rather than creating a new feature, thus they’re right and “evolutionists” are wrong.

I’m assuming that the specific “blind cave fish” PZ’s referring to is A. jordani rather than the blind form of the species A. mexicanus? If so, can this be considered another example of speciation in action?

Wheels said:

Actually I think this is a much rarer form of anti-evolution criticism …

Yes, yes, but it led to a curious declaration at the end:

Meanwhile, ID proponents seek to explain a far more interesting aspect of biological history: the origin of new complex biological features. Despite his quotation of Michael Shermer on the evolution of the eye, Hitchens has yet to do that.

“Sha-ZAM! Gosh I’m holdin’ my breath waitin’ for the revelation.”

The really appalling thing about Luskin is not his total cluelessness. Such folk are not so rare. What is appalling is that the DI would even consider using him as even an informal spokesman, instead of disclaiming any connection with him.

I was poking around on references to Larry Fafarman this weekend. Astounding as it seems, he makes Luskin look good, and the DI still doesn’t try to distance themselves from him.

White Rabbit (Greg Goebel) http://www.vectorsite.net/tadarwin.html

Re Bill “The Joker” Dembski:

Ian said:

Has he gone underground, died of embarrassment, or finally become as irrelevant as he was always threatening to do?

They probably caught him and locked him up in Arkham Asylum again.

White Rabbit (Greg Goebel) http://www.vectorsite.net/tadarwin.html

Off-topic breaking news:

Peter Enns is yet another theologian getting expelled. The Westminster Theological Seminary has accepted his resignation ahead of the 4-day heresy trial hearing they had scheduled. Google on the good professor’s name, and try not to laugh too hard.

But PZ, “the-designer(s)-did-it” is the right answer. Or did you think those eyes “poof” disappeared overnight. These little designers we call cells constantly design an redesign themselves by harnessing random variation and selection. You can say what you want, but the intelligence within cells outstrips even our best attempts at AI. :)

Yep, these little “designers-did-it”… But but but, who designed the designers?

Anyway, the histone code and riboswitches are bound to play an overwhelming role in transformations like these. Random variation and selection are going to take back seats as explanations imo. Just my 2c.

But but but, who designed the designers?

Well, following your metaphor, that would be their ancestors. ;)

Gee… no way, you must be kidding…

Those little ancestor designers also designed an redesign themselves by harnessing random variation and selection.

But but but who designed their ancestor “designers”…

No no, they “designed” their descendants, not themselves.

Of course, that’s really only the same sense in which people “design” their descendants - i.e., not really.

Probably a better way to put it would be to say that the genome designs its successor, since obviously the individual critters don’t design anything.

Henry

Ian said:

Whatever happened to Billy “The Kidder” Dembski? I used to see snippets about him all over science blogs and here at PT, but now we never hear of him.

Has he gone underground, died of embarrassment, or finally become as irrelevant as he was always threatening to do?

He just sits around whining on his blog, Uncommon Descent, with his undereducated followers. He doesn’t actually accomplish anything scientific, of course. We watch the dumb things they say and laugh about it here: http://www.antievolution.org/cgi-bi[…];act=SF;f=14

Sorry, something must have been lost in translation here.

Should have said: Those little ancestor designers also designed and redesigned, themselves through random variation (meaning copies of themselves), or ie. designed themselves with little variations by making copies of themselves by harnessing random variation and selection. Intelligence within cells outstrips even our best attempts at AI. :) Not so difficult really.

Still…who designed their ancestor “designers”…

Oh. Well, that would be the Flying Spaghetti Monster (FSM for short).

Now that is just silly IDiocy… The “TARD4FSM”

Just in case it gets lost in translation AGAIN… TARD4FSM = The Argument Regarding Design for the Flying Spaghetti Monster

The Pasta One is unnecessary (though delicious).

If thisisfunny’s definition of ‘design’ doesn’t require intelligence/purpose, then nonliving matter can do it too, and no ancestral designer is required. Of course, we could then call the orbits of the planets designed (i.e. by natural forces), too, which may or may not be a good thing.

thisisfunny said:

Sorry, something must have been lost in translation here.

Should have said: Those little ancestor designers also designed and redesigned, themselves through random variation (meaning copies of themselves), or ie. designed themselves with little variations by making copies of themselves by harnessing random variation and selection. Intelligence within cells outstrips even our best attempts at AI. :) Not so difficult really.

Still…who designed their ancestor “designers”…

Henry J said:

Oh. Well, that would be the Flying Spaghetti Monster (FSM for short).

Wheels said:

I’m assuming that the specific “blind cave fish” PZ’s referring to is A. jordani rather than the blind form of the species A. mexicanus? If so, can this be considered another example of speciation in action?

Anoplichthys jordani is considered to be a synonym of Astyanax mexicanus, that is, the Blind Cave Tetra is considered to be a blind race of the Mexican Tetra. They were originally thought to be two distinct species, but, the discovery of beady-eyed Mexican tetras near the mouths of the caves of the Cave tetras made researchers and aquarium hobbyists realize that there was a gradient from sighted, pigmented Mexican tetras to the pigmentless, blind Cave tetras. That, and they both readily interbreed with each other. In fact, didn’t Prof. Myers write a blog about how it’s possible to breed functioning eyes back into the Cave tetras by repeatedly crossing them with Mexican tetras?

Heh. The other day I was walking through an empty apartment with a double handful of tools and stuff and paying more attention to balancing the unstable load then to where I was going and I gave the dining room chandelier a header that sent it swinging and I reeling. Now I know how to describe such a thing:

It was a luskin moment. I pulled a luskin. I got luskinned. I gave it some luskin, or, put some luskin on it. Luskinized!

Had the fixture actually fallen, or had I lost my load (neither happened), that would have been a double luskin.

Hand the fixture fallen and caused a unforeseen but inevitable (due to a previous, unfortunate modification by an unknown agent) short circuit damaging the wiring system of the entire apartment, that would be a triple luskin.

Anyone who reads this far and hasn’t at least chuckled has just luskinned, or had some ludkin put on them, and probably does not know it.

And we see that, of course, cdesign proponentsists are more than happy to exploit convenient semantics. It means I have to try and find less ambiguous (or at least less exploitable) ways to describe everything from natural processes to “Creationists.” Unfortunately it’s just an example of the fact that it’s harder to appear successful arguing against a dishonest opponent than one who strives for accuracy, which is why it’s usually counter-productive to engage in a live debate with anti-evolutionists. At least the internet allows me the utility of hyperlinks and a limitless timeframe.

For goodness sakes guys, Casey (and ID) agree that Darwinian Evolution is capable of this kind of micro-evolution. Without this ability living organisms would not survive long in a changing environment. All this does is confirm how wonderful God’s design really is. It doesn’t explain how species and new body plans developed. Even the ALTENBERG 16 do not think that the current evolutionary synthesis begins to explain it. All the huffing and puffing and insults thrown around on this site just convince me that you don’t have real answers.

Both sides have huffing and puffing.

So far as I’ve seen only one side has produced descriptions of evidence that actually supports the principles of their model.

Dolly Sheriff said:

For goodness sakes guys, Casey (and ID) agree that Darwinian Evolution is capable of this kind of micro-evolution. Without this ability living organisms would not survive long in a changing environment. All this does is confirm how wonderful God’s design really is. It doesn’t explain how species and new body plans developed. Even the ALTENBERG 16 do not think that the current evolutionary synthesis begins to explain it. All the huffing and puffing and insults thrown around on this site just convince me that you don’t have real answers.

The cdesign proponentsists always misrepresent what science already knows and is currently doing. These so-called “micro-evolution” and “macro-evolution” terms are distinctions which are totally arbitrary and are exploited ruthlessly by the cdesign proponentsists. They have no particular meaning and little usefulness in science.

There no rules or laws forbidding evolution from continuing right on up from simple systems to extremely complex systems. And it is a well-known fact that cdesign proponentsists always dodge any explanation of just what such rules or laws they have in mind.

In fact, there is considerable tantalizing evidence that points to many possibilities for the evolution of living organisms from non-living systems. The fact that living systems are so complicated and so sensitive to billions of contingences is what makes the search difficult and time consuming. Technology itself is still evolving; we are just gaining capabilities that weren’t available only a few years ago. So it is not surprising that there is considerable excitement and lots of new ideas to be explored.

Just because cdesign proponentsists have short attention spans, lack the stamina and imagination required for research, and can’t tolerate the lack of instant gratification doesn’t justify their projecting their own shortcomings onto the science community.

OK Dolly, we have established that ID agrees, at least to some extent, on at least some evolutionary concepts.

We all agree on that some form of evolution exists, apparently, and we all agree that it manifests itself (eventually) in genetic mutation (that’s how changes are passed to the next generation).

We seem to agree that while most mutations are neutral or detrimental, at least some mutations lead to a survival advantage, and that is important.

We seem to agree that mutations are additive, that is, you can have an organism that has one mutation, and then add a second one. There is no apparent mechanism that limits an organism to one mutation.

So here’s the million dollar question, which you, like all ID advocates, avoid like the plague; what limits the mechanism to “micro evolution”? Why can it only take 5 steps and then has to stop?

You’ve established that it can walk, why can’t it go for a long, long stroll?

It’s a really simple question, Dolly. Why is it that the ID crowd advocating the micro-evolution shibboleth can’t ever seem to answer it?

stevaroni said:

So here’s the million dollar question, which you, like all ID advocates, avoid like the plague; what limits the mechanism to “micro evolution”? Why can it only take 5 steps and then has to stop?

You’ve established that it can walk, why can’t it go for a long, long stroll?

It’s a really simple question, Dolly. Why is it that the ID crowd advocating the micro-evolution shibboleth can’t ever seem to answer it?

You are absolutely wrong in saying ID ignores this question. In fact it is the most important question in ID today and Mike Behe devoted an entire book to answering this question : “The Edge of evolution”.

Dolly Sheriff Wrote:

You are absolutely wrong in saying ID ignores this question. In fact it is the most important question in ID today and Mike Behe devoted an entire book to answering this question : “The Edge of evolution”.

Well, you have put your finger on one of the most serious problems with the ID activists; they write books and constantly kibitz from the sidelines, but never ever learn how to do any research or make any effort to understand what real researchers have discovered.

Plus their arguments don’t address the questions that an actual alternative hypothesis would have to address, i.e., why would nature show the patterns expected by the current theory, if something basic were actually wrong with it.

Henry

You are absolutely wrong in saying ID ignores this question. In fact it is the most important question in ID today and Mike Behe devoted an entire book to answering this question : “The Edge of evolution”.

Again, no answer.

“Go look in this book.”

Not “OK, here’s two good links to real research papers that actually demonstrate a mechanism”, which would constitute what we, in the real world, would call an answer.

And for the record, “The Edge of Evolution” boils down - in a nuthell - to a giant argument based on probabilities. It has been dissected ad nauseum here by people who actually understand statistical math, and found to be significantly flawed.

Michael Behe is not exactly what you might call good with statistics. Back in ‘06, Behe found himself on the witness stand in Dover, where he got to describe his theories under oath.

During cross examination his statistical calculations were absolutely demolished by lawyers who had actually taken the time to do the math. At one point Behe had to defend his assertion that a certain mutation was so improbable it was unlikely to ever happen. The lawyers forced him to go through his own math, step by step with real numbers, revealing that the mutation Behe had just testified was too improbable to ever happen was actually occurring somewhere within the courtroom every 90 minutes or so.

But Michael Behe is best known for his immortal testimony “These are heavy”, his insightful comment on the 60 or so published works entered into evidence to refute his sworn assertion that a certain aspect of the immune system development had never been documented.

Behe is, in a nutshell, such a discredited biologist that the biology department at Lehigh University at one point put a disclaimer on their website, signed by the rest of the professors, saying that Behe does not speak for the rest of them, and please, please, please don’t judge the quality of our school by the uttering of this one fool.

So, anyway, back to the proximate question at hand. Behe’s all you’ve got, isn’t it? You don’t really have any mechanism to limit evolution to micro-evolution, do you?

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This page contains a single entry by PZ Myers published on July 28, 2008 8:41 AM.

Snake segmentation was the previous entry in this blog.

Lankester’s Migrational Selection of Blindness is the next entry in this blog.

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