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.

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
Draconiz · 28 July 2008
Thank you PZ ^_^
David Stanton · 28 July 2008
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.
iml8 · 28 July 2008
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
Eric · 28 July 2008
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.
Frank B · 28 July 2008
Samuel Huckins · 28 July 2008
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.
watercat · 28 July 2008
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.
John Kwok · 28 July 2008
Rob · 28 July 2008
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.
SteveF · 28 July 2008
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/cluster/pdf/coyne/Hoekstra%20&%20Coyne%202007.pdf
Kevinv · 28 July 2008
"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?
skyotter · 28 July 2008
the gene was named for the video game character
Mike · 28 July 2008
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.
Frank J · 28 July 2008
Ian · 28 July 2008
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?
Wheels · 28 July 2008
iml8 · 28 July 2008
iml8 · 28 July 2008
william e emba · 28 July 2008
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 trialhearing they had scheduled. Google on the good professor's name, and try not to laugh too hard.thisisfunny · 28 July 2008
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.
Henry J · 28 July 2008
thisisfunny · 28 July 2008
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"...
Henry J · 28 July 2008
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
steve s · 28 July 2008
thisisfunny · 28 July 2008
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 · 28 July 2008
Oh. Well, that would be the Flying Spaghetti Monster (FSM for short).
thisisfunny · 28 July 2008
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
Eric · 28 July 2008
Stanton · 28 July 2008
Crudely Wrott · 28 July 2008
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.
stevaroni · 28 July 2008
Henry J · 28 July 2008
caerbannog · 29 July 2008
Rough Guide to Evolution · 29 July 2008
PZ didn't provide citations: here is a link to Jeffery's research output:
http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=DetailsSearch&Term=jeffery+WR%5BAuthor%5D
The (somewhat out of date) Jeffery lab web site is here:
http://www.life.umd.edu/labs/jeffery/
complete with movies on lens transplants!
thisisfunny · 29 July 2008
iml8 · 29 July 2008
Stanton · 29 July 2008
iml8 · 29 July 2008
Frank J · 29 July 2008
Joel · 29 July 2008
Re: origin of the gene name hedgehog:
"The cuticle from hedgehog mutant larva has a continuous pattern of denticles along the anterior-posterior axis instead of alternating patterns of a band of denticles and then a band of naked cuticle. The lawn of denticles over the larval cuticle is reminiscent of the spines of a hedgehog."
From Flynome. http://www.flynome.org/
jasonmitchell · 29 July 2008
I wonder if Luskin even realizes how much he hurts ID's case?
allegedly ID isn't about religion - but the 1st thing luskin does is point out that Hitchens is an atheist (as if that is relevant)
allegedly ID is a BETTER explanation for biological diversity - but Luskin acknowledges that "Darwinian processes", and "random mutation and natural selection" are the BEST explanation for blind cave fish (the subject of the article re was criticizing is blind salamanders)
so let's take a look at how weak ID is now
ID "accepts" (or some ID proponents accept):
1) the earth is OLD
2) common descent
3) random mutation can change traits
4) mutations are heritable
5) natural selection (at least sometimes)
yet other proponents of ID actively lobby against 1-5 being part of public school curriculum - how dumb
iml8 · 29 July 2008
Bill Gascoyne · 29 July 2008
P.J. O'Rourke (1947- )
Frank J · 29 July 2008
jkc · 29 July 2008
iml8 · 29 July 2008
Torbjörn Larsson, OM · 29 July 2008
John Kwok · 29 July 2008
Science Avenger · 29 July 2008
Frank J · 29 July 2008
John,
Thanks, those books are still on my to-read list.
Nevertheless I have read countless books and articles about the "common ancestry" of ID and classic creationism, and have read many times about who "is" a "creationist" or a "YEC." While it's futile to speculate what they privately believe (Behe could be a closet flat-earther for all we know), these people, unlike those who remained at YEC and OEC organizations, are abandoning the only claims that could make their alternative scientific. Namely starting with a basic "what happened when" (Scott's phrase). Classic creationists do it, so why not just do it without reference to the Bible or "creation"? One possibility is that they’re just not confident that the evidence will support any of those positions, all of which have been thoroughly discredited on the basis of their failed and mutually contradictory claims. Independent of their status as religious approaches. Ronald Bailey suggested that in even stronger terms. And ID has gotten even more evasive since then.
As for Nelson possibly being an Omphalos creationist (if not a closet OEC or even TE), someone speculated on that as a possibility while he was posting here a few months ago. I asked him if it were true. He ignored my question while answering others, then went away. He had nothing to lose by saying “no.” Besides, Glenn Morton also came from the YEC movement.
John Kwok · 29 July 2008
James F · 29 July 2008
Frank J · 29 July 2008
James F:
Yes!!! That's even better than I expected!
About 3 years ago I read (or imagined reading, if you ask some others) a PT comment whereby someone contacted 6 signatories and 5 admitted having been misled. No one has ever been able to find it, so about a year ago I just gave up and left it as a mystery. This video at least restores my confidence that I was not imagining it (maybe not at PT?). I only know of one signatory who had his name removed so far, but unless this guy is pulling is own scam, it looks like there will be more.
I'm not at all surprised that 14 of 16 biologists admitted common descent (CD). After all, these were mostly people approached by the scam artists, although the list was "padded" with quite a few DI activists (isn't that a conflict of interest, BTW?). In contrast, the ~20 who testified at the Kansas Kangaroo Court had a record of anti-evolution activism. In that group, most were old-earthers, but only a minority conceded CD. More importantly they were mostly very evasive, including answering the wrong question in several cases. The "unaswerable" question is: which of these 2 groups has more of a vested interest in not saying what they really think?
The only thing that bugs me is that this guy only used a list of 101 names. AIUI, it's at ~800 by now. I saw some emails dated 2007 and 2008, so he either began his survey much earlier, or didn't think that the added names changed anything significantly. I also have some quibbles with his statistics, but it doesn't detract from his point.
Here’s another list that I like to refer to when the “Dissent” list is discussed. These were not scientists who volunteered to sign a “dissent” statement, but were quote mined from their research as “challenging” “Darwinism.” To no one’s surprise, “None of the 26 respondents (representing 34 of the 44 publications in the Bibliography) agreed that their cited work provided any support for "intelligent design"; many were indignant at the suggestion.”
Wheels · 29 July 2008
Henry J · 31 July 2008
Wheels · 31 July 2008
Apparently the little giant thing was capable of taking off and slipping away into the night. That's how it escaped my revengeance.
fnxtr · 1 August 2008
Still wondering if there's a Spiny Norman gene.
James F · 1 August 2008
Eric · 4 August 2008
Sorry I didn't respond earlier, was on vacation...
In answer to both Henry J and thisisfunny, my point was that most creos use a narrow teleological definition of "design" that implies sentience and purpose. (And don't ask me to define sentience, I'm trying to represent the creo perspective to clarify my post - not defend to their perspective.)
Broaden this narrow definition and many other things could count as design/designed. This could be useful for science. Broaden the definition too much, however, and the word becomes useless. That's what I meant by 'may or may not be a good thing.' Torbjorn also alluded to the problem of an overbroad definition of design when he mentioned that calling any function "problem solving" begs the question.
Eric
Henry J · 4 August 2008
Wheels · 5 August 2008
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.
Dolly Sheriff · 5 August 2008
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.
Henry J · 5 August 2008
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.
Mike Elzinga · 5 August 2008
stevaroni · 5 August 2008
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?
Dolly Sheriff · 6 August 2008
Mike Elzinga · 6 August 2008
Henry J · 6 August 2008
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
stevaroni · 6 August 2008