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.
Great article PZ! please be a true elitist bastard and re-post this on the Pandasthumb for all the unwashed mass to see!
Simon Coude says
They actually called a gene Sonic the Hedgehog?! Biologists are even funnier than phycisists.
Fantastic re-rebuttal PZ! I learned something knew, which is something I doubt Luskin will ever be able to do.
Simon Coude says
It’s monday morning, and I meant something NEW.
Matt Heath says
#2: I’m not sure that they are funnier than physicists; Feynmann wanted to call the quark the “parton” (as in Dolly). That’s comedy gold.
I don’t get it, so [Insert Intelligent Designer] sits there as supernatural artificial selector and directs or squishes generations of species, including for example the 350,000 different beetles or something – whilst also prodding at the entire universe and people don’t find this too taxing on the brain and logic sensors?
I agree with people like Professor Myers, Richard Dawkins or even Dr Hitchens because their explanations are so much easier to understand than “Goddidit” – I am a historian and English graduate for Quetzalcoatl’s sake and yet Evolution by Natural Selection isn’t completely out of my sphere of comprehension! ID is bollocks in comparison, it explains nothing to me except complexity where there shouldn’t be, its such a waste of time!
If I can do it, why can’t they? :)
Ms. D says
There’s seriously a gene called Sonic hedgehog? That is amazing. Of all the videogame characters they had to choose Sonic.
James F says
Ugh, I made the mistake of peeking at the comments on Hitchens’ article…oh, my head. PZ, you ought to link here in the Slate comments section.
Rev. BigDumbChimp says
Our old buddy FtK wrote about this too.
I won’t link to her but…. oh boy.
Because they actively, willfully, surpress information that does not fit their preconceived notion of how things ‘ought’ to be.
In fact, what they are doing, is impressive: they take facts and do the most amazing psychological backflips to dismiss them. Or they just ignore them. Or they half-ignore them, give an answer that doesn’t really give any response to the real point of the other, and continue on as if nothing happened.
Now, those that follow these inane ideas, only need to believe them and selectively read what they want to read, and that’s that.
#2 and #6 – there is actually a whole family of Hedgehog genes. I believe in the fruit fly this family of genes originally could cause them to be spiny and hairy. When they find other genes in the family they give them alternate names, and when they first identified Shh (in the 90’s) they came up with a new Hedgehog variety that hadn’t been used for names yet. My wife did her thesis working on the Sonic Hedgehog gene expression pathway.
That’s pretty cool. And you’d think there should be some advantage to eye loss, given that it seems to happen so frequently to species in places without much light.
“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.”
Well. You know. That was caused by Our Sin.
Well, sonic was really popular at the time. And it was a version of the already discovered Hedgehog.
Simon @#2: It’s “sonic hedgehog” not “sonic THE hedgehog”, and if you think that’s funny you should read some scientific names (such as Vampyroteuthis infernalis, the vampire squid from hell).
Laser Potato says
What do you call a fish with no eyes?
Lilly de Lure says
Ms D said:
IIRC it’s part of a family of genes named “Hedgehog”, after the creature they were first discovered in. When this member of the hedgehog gene family was discovered someone found the urge to make the joke irresistable.
Seriously though, if you think that’s bad, you should see all the different names given to the “Fringe” gene family!
Great article PZ – although watching you going after the flaws in an argument by Casey Luskin does bring the words “fish” and “Barrel” to mind (you’d think he’d learn but then, even the cave fish he’s so wrong about aren’t so blind as those who won’t see)!
Is it wrong that I actually enjoy reading Luskin’s articles?? They never fail to entertain.
You get the feeling that he takes his articles home and his mom sticks them to the fridge.
Someday he’s going to reveal that he was joking all along, right??
I wonder if Casey will ever apply his keen mind to the evolution of Nylon-eating bacteria.
luskins post, before even getting to the sonic gene (pz) his argument is flawed from the onset.
quote “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.”
so, random mutation destroy complex features, so what hes saying is ‘goddidit and then random mutations tooketh away’ no doubt the sin of adam meant god decided to be mean to the poor blind cave fish, oh, hang on, the poor blind cave fish, isnt it strange how the creature with random mutation destroyed eyes JUST HAPPENS to live in a dark cave, well isnt he lucky as he doesnt need the eyes down there (his fins are ok though, and his swim blasser, and his jaws, and his scales and his gonads, i wonder why they havent also degenerated?) if random mutations are so good at destroying complex parts of bodies why dont we see this up on the surface too? i suppose luskin could say ‘eyes do degenerate just as much up here as down there, its just that up here the orgs with them will suffer the obvious disagvantage and thus perish’ oh and not pass on their genes, i think thats called ‘natural selection’. no god required for that one.
i suppose what luskin et al do is come out with stuff that sounds clever because the average twinkie munchin hillbilly christian creationist simply isnt going to know any better.
Lilly de Lure says
Oops – I just rechecked and you are quite right about this – consider my post corrected!
It does indeed!
pz, interesting expalantion, how the selection for the jaw etc actually affect the eye too, kind of by chance, up until now i assumed that it was lack of selection FOR working eyes that allowed accumulations of ‘degeneration’ effects.
next the DI brigade will be saying ‘oh, see its a ‘positive intelligent degenerative’ change therefor NS couldnt have done it so Godidit!!
Jared Lessl says
Actually, I’m surprised that the induced eyes actually work at all. Eyes are pretty complex things, there’s lots more ways to make nonfunctioning eyes than functioning ones. Without selection pressure to keep them in good order, the genes for coding them would eventually randomly wander into “does not work” territory, no?
Dammit, have been gazumped by a million people explaining why they call it sonic.
I’m glad fruitflies were so popular, drosophilists have enough sense of humour to give them interesting names. (I swear there’s something about fruitflies that make drosophilists crazy). Iirc most of the C. elegans gene names are random collections of letters and numbers (like Uncx4.1), and the genes discovered in mice and humans tend to be plain boring.
Emmet Caulfield says
I’m pretty sure Christopher Hitchens holds no doctorate.
“Breathtaking[and coffee spitting] inanity”!
In Buffalo there’s a creek that has a 4 mile long section that was covered over with a tunnel in the late 1920s.
People walking through the tunnel to explore it have seen and taken photos of fish lacking pigment… I dunno if they lack eyes yet.
Are there any known examples of such changes taking place within a span of decades?
Why do they keep letting Luskin comment on these issues? Did they learn nothing from the last go-round? He’s clearly out of his league…
Although… perhaps it’s worth considering that this is the best they can do… interesting.
The Science Pundit says
Are these the same blind cave fish you wrote about in SEED (great article, btw) a few months back? The explanation sounds very familiar.
Damian with an a says
This is a fascinating article on eye regression in cavefish:
And another about why eye loss occurs:
@23: You’re right. Hitchens graduated Oxford with a 3rd, and currently holds no postgraduate degree, not even an honorary one.
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 MAGIC 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 MAGIC only strengthens our argument.
I enjoy ridiculing creationists, especially the Christian creationists of the Discovery Institute. What I do is visit creationist blogs, choose an idiotic paragraph like the one above, and substitute the word MAGIC for every occurrence of the words ‘Intelligent Design’. For ‘designer’ I substitute ‘Magic Man’.
Intelligent design means magically created, and magic is an extremely childish idea. I like to remind the lying creationists how hopelessly stupid they are.
Rev. BigDumbCHimp says
Or the time before, or the one before, or the one before that, etc….
post #21 jared.
they might appear normal superficially but you theres a good chance that they are ‘sub optimal’ compred to the average eye of a light exposed relative, it would be hard to determine that.
Re Celtic_Evolution #26: Luskin is the best they can do. Since ID is a political movement, they don’t actually need anyone who can do real science, they just need people to point at the confusing parts of biology, and call those parts ‘God’. Luskin fits the bill nicely.
get ready for a round of trolls claiming atheists are immoral murderers:
Meanwhile, MAGIC proponents seek to explain a far more interesting aspect of biological history: the MAGICAL CREATION of new complex biological features.
Richard Eis says
Why are the ID proponents seeking to explain the origin of complex biological features? They already KNOW surely?
We know what he REALLY means, but come on he could at least try to be convincing/realistic. Is he going to resolve world hunger afterwards aswell?
I do love the fact that every time he tries to slap down evolution, i get a fascinating and positive lecture on genes from PZ. Huzzah
Michael Barrett says
#32 – it wouldn’t be too hard to find out.
Put pale, tunnel fish in tank A, put ‘normal’ fish in tank B. Put both tanks in a controlled darkened space.
Time feedings to the turning on of a light. Use progressively dimmer settings of the light, and record the response times of the fish.
If the pale cousins fail to respond, or respond differently as lower levels of light, then their eyes are different.
You could also dissect them and find the mean number of rods and cones on the retina….but then you wouldn’t get to have fish tanks in the dark.
I note that the creobots/IDiots have changed tactics some (others here have likely already detected this goal post shift) in seemingly giving credence at least to the existence of evolution. They just think it screws things up.
So evolution exists, but it screws things up, and that’s about it. If ya can’t beat ’em, make the winner’s cool stuff seem like it’s useless garbage everybody already knew about.
Interesting strategy, only for how it continues to add to the uh, complexity, of their convoluted, inconsistent and lysenkoic excuses for a designer.
So God created these darkness-dwelling species with eyes just to tease them?
I don’t see how this argument is supposed to run. Some of these cave organisms are separate species from surface varieties, no? So it seems clear that, by ID logic, the blind organisms can’t have evolved from the sighted ones, as that would be an example of “macroevolution”. Given that, it really does seem like they are forced to claim that God actually created these blind species with working eyes, functionality that would be completely useless to them and which has been lost. This really does make the Designer look less than intelligent (and more like a complete wanker).
“And the constant citations by Darwinists of “loss of function” examples as alleged refutations of ID only strengthens our argument.”
There’s nothing to refute. ID is purely inductive reasoning: we haven’t answered all the qeustions so it MUST be god. Science is purely deductive: all the evidence points to this conclusion, so thats what we accept for now. If something else changes things, then we’ll toss out that theoretical framework and build another. Thats the beauty of science – its iterative, adaptive, logical, dispassionate, rigorous and robust. All the things that ID isn’t, and precisely why it will fail in the long run.
Scientists are as likely to be comedians as any other group of people. So long ago that it seems not to have made it to the internet, some biologists had a publication called something like The Worm Runners’ Diary, about working with planaria. It was both funny and informative, and despite having read it a very long time ago, I can still recall quite a bit of information about the results of their experiments. Humour is a useful aid for learning.
Rev. BigDumbCHimp says
Seems his motives are in line with many fundies.
Funnily enough, Hopi Hoekstra and Jerry Coyne Hoekstra and 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.
I was a bit bothered by Hitchens article, which did give the impression of “reverse evolution” When loss of eyes is actually a positive adaption -progress- Just like eyes themselves are progress for those of us who live in the light. PZ’s post I like alot better, because it explains how.
Creationists: Please just give up. You lose, you have lost, and you are going to lose every future argument.
It is hard to find people who will routinely put out gibberish in press releases. Most who would do so are too busy fighting off demons from the other dimensions or hiding in their basements from the Grey UFO aliens.
There’s nothing in the story suggesting he is an atheist and if he was why would he pick a Unitarian Church? They’re almost atheists themselves.
Jared Lessl says
> they might appear normal superficially but you theres a good chance that they are ‘sub optimal’ compred to the average eye of a light exposed relative
Gotcha. Makes sense. There’d be a smooth degradation in functionality depending on how long it’d been since the species had taken up residence in the dark. More recent arrivals’ eyes might only be slightly sub-par, while anciently blind species’ eye genes would be so far gone they’d be more likely to resemble a tumor than provide sight if they were ever turned back on.
Wonder if there’s any daylight species that are descended from blind species who left their cave and managed to survive. It might just be a matter of switching their eye activator back on, or they might have to redevelop them practically from scratch.
Matt Hussein Platte says
Is he like, um, you know, a real lawyer or did his JD come from ID as well?
Matt Gerber says
After a certain point of ridiculousness, I sorta just start to feel sorry for proponents of ID.
#46, I was thinking they’d latch on to this bit:
“Karen Massey, a neighbor to Adkisson, told the Knoxville News Sentinel about a lengthy conversation she had with Adkisson a few years back in which she told him her daughter had just graduated from a bible college. She said she was surprised by his reaction when she told him she was a Christian.
“He almost turned angry,” she told the newspaper. “He seemed to get angry at that. He said that everything in the Bible contradicts itself if you read it.” She also said Adkisson spoke frequently about his parents, who “made him go to church all his life. … He acted like he was forced to do that.”
Doesn’t mean he’s an atheist, but to them it would.
Of course, even if he is an atheist, nobody here has argued that you can’t be an atheist AND psychotic.
There’s nothing in the story suggesting he is an atheist …
I assume he’s referring to where he got upset when a woman said she was Christian, and then he went on to rant about how the Bible contradicts itself. Since Bible contradictions are often cited by atheists, someone is sure to make the leap of logic that this guy must also be an atheist.
I’m betting that the man was a Christian (he was raised Christian according to the article) who experienced some trauma to make him “lose” his faith which is more anger at God than actual atheism. Either that or he was just psychotic.
Terry Small says
Excellent rebuttal, but I sincerely doubt Luskin is actually capable of comprehending the point you made just there.
I request compensation mate,I have been debating the people on mixing memory for hours now,and their intellectual level is about that of your average catholic troll.
Youre not paying me enough for this shit !!
Glen Davidson says
I’d give Luskin one thing, which is that loss of function is not as impressive as gain of function. Hitchens is hardly the best at arguing evolution, even though he did get it right as far as he went.
Of course what’s impressive is how loss of function often becomes gain of function in some other area. Many cases of “cave blindness” are indeed thought to exist not just because it’s useless to waste energy on eyes that have no light to see by, rather they shut down the eyes in order to free up nerves in their brains to enhance other senses, notably hearing and touch.
Likewise with our paltry olfactory senses. They seem to be that way not just because smell isn’t an especially useful sense to us (that is, compared with how useful it is to dogs), it’s also so that our visual sense can take over more brain. The evolution of the red cones in our brains may have been one of many phenomena which reduced olfaction in our ancestors.
So sure, there’s more to it than Hitchens knows. There’s certainly far more to it than Luskin knows, or than he will admit. Many of the evolutionary processes that ID constantly claims “could not happen” occurred by taking over some other function, for the sake of another function that is now more important.
OT The Tennessee shooting.
Not clear why the shooter targeted the Unitarian Universalists.
Apparently he described himself as “confederate” and “old south”. He might have been one of those reactionaries who thought the Abolitionists and commies of the Unitarian church needed to be taken out. Political, racial, or cultural motives.
It will come out and probably soon. Just have to wait and see.
Benjamin Franklin says
Craig @ # 138
So when do you think we will find out out what “hateful things” the looney gunman shouted out during the church’s production of Annie?
‘Us’ creationists – he pretty much lost me there.
The fact that he is wrong, however, is central to his point.
Pierce R. Butler says
confused @ # 22: (I swear there’s something about fruitflies that make drosophilists crazy).
Drosophilism is a crazy ideology in the first place, and should never be taught without fair and balanced treatment of alternative theories!
Damian with an a @ 27: … functional eyes in darkness do not stop sending information to the brain: “I detect no light. I detect no right…”
Yabbut how long until they evolve an eye that can detect wrong?
Marine Geologist says
extatyzoma @ 18
[/i]if random mutations are so good at destroying complex parts of bodies why dont we see this up on the surface too?[i/]
Actually I think you do see this on the surface. If ID/creationists and some of the crackergate trolls are any indication, brain functions for logic and reason are certainly being destroyed and the destruction propagated.
Breaking news, Shooter mad a libruls.
It seems like after the last church shooting, the shooter was initially incorrectly identified as an atheist. Not that it matters much, but I suspect this will be the same. As someone else already pointed out, being atheist does not remove all possibilities of psychosis.
They are only “wrong” if you are looking at their material as science. If, on the other hand, you recognize it as propaganda meant for the barely, or even wrongly, educated, it makes perfect sense. The crap they shovel is meant to be warm and comfortable, in a “oh that makes sense to me” sort of way.
Richard Eis says
I request compensation mate,I have been debating the people on mixing memory for hours now…
Yeah, it’s all character attacks and really bad analogies. They are really missing the point of the whole cracker stuff you did.
I don’t guess I “broke” much news. PZ beat me by ten minutes or so. Story of my life.
Oh, the Sonic Hedgehog Gene?
That’s the one that supresses the Doctor-Robotnik gene, right? ;)
Nerd of Redhead says
Ahh. Nothing like a little science reading during the morning coffee break. Another excellent article by PZ.
This is also evident in some hyoomans as well.
Note those with overdeveloped jaws, who exercise them constantly, tend not to see things very clearly. The hearing is effected as well.
“Watchtower Bible and Tract Society”? – That’s my alma mater, so to speak.
I hope they realize that the WBTS produces no original material in this area. They simply copy from other sources, who probably copied from still other sources. I actually found one case where, at the end of the circle, it turned out they were actually quoting themselves.
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. 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 now inserts a lactate in its place. The lactate can no longer form a key hydrogen bond with vancomycin because of the D-alanine (NH hydrogen bond donor) to lactate (O hydrogen bond acceptor) 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.
Norman Doering says
Hitchens is a piker. I read his article and he’s just getting started on his understanding of biological evolution.
Wait until he learns about genetic algorithms and evolutionary programming and then how it relates to artificial intelligence. I can’t wait to read him on it. I’m too much a piker at writing to give it it the powerful expression he probably will.
He’s about where I was when I first started reading Panda’s Thumb and I’m still not at PZ’s level of understanding.
The reason Hitch says that “there are some arguments you just underline” (because they’re so crazy) is something he’s says because he knows he’s not ready yet to argue those points in his debates. He knows he’s a piker and he sticks to what he can argue.
bybelknap, FCD says
I’m sort of a masochist for creotard stuff, that’s why I subscribe to the worldviewweekend newsletter, so I can get links to things like this inane babbling in my email every few days.
It takes this ninny-hammer, a “Dr.” Ron Carlson, 5 minutes to set up the tired old “we accept ‘microevolution’ but not ‘macroevolution’ and the evilutionists are LYING to you, YES LYING!” baloney.
Actually, I couldn’t watch beyond that. I want my five minutes back please. I’m sorry in advance to anyone who follows the link and loses IQ points in the watching.
OT The Tennessee shooting.
Not clear why the shooter targeted the Unitarian Universalists.
My guess: it was the closest one to his house.
Norman Doering says
Are you trying to insult Jay Leno?
But PZ, “the designer 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?
“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.”
Nawww. GOD changed the bacteria intentionally because he wants people to suffer and die.
Wait. So Hitchens finally learnt some biology?
Hasn’t that been the main complaint against him re these debates? What’s next? Will someone give him a copy of Origin?
Don’t be silly, Hitchens will much rather down 7 double-tot whiskeys (or whatever brew he favors) before he decides to educate himself.
Brownian, OM says
That’s not fair. Some of us are perfectly capable of learning whilst pickled.
Why, just the other day I had the epiphany that the guy sitting next to me wash the besht–shh, listen, I wanna tell you somethin–no, this guy; thish guy, is totally the guy–forget it, you don’ even know what I’m talkin’ about. You don’ know him. You don’t even know hi–hey, whaddaryou lookin’ at? You’re sshtupid.
Can someone further explain this process, including how they know that the transplanted tissue didn’t contain stem cells that grew into the eyes?
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.
Scooter #66 — Ten points!!!
All of the above is wrong!
Who robs cave fish of their sight? We do!
Seriously though, I wanna know if there’s been observed loss of pigment and eyes in fish in man-made tunnels. Like, observed evolution.
Dammit, where’s all the scientists on these here science blogs?!?!
agreed, what i was thinking was that very subtle initial differences might be hard to determine, ie the very slight sub optimal conditions arising possibly quite soon to subsequent generations after being in a dark environment.
but yes, it would be quite easy to devise experiments that could detect differences esp where they were more severe. indeed a fish could have a normal looking eye but have a useless optic nerve, something only experiment/dissection could verify.
michael, whoops: thats your #37, my #32!!
quote “Why are the ID proponents seeking to explain the origin of complex biological features? They already KNOW surely?”
yup, i thought that too. its rather funny, i just wonder how they actually propose to do this?
As much as I respect and admire Hitchens, I certainly would not expect to learn much about biology from him. For that I look to PZ and Dawkins.
marine geologist #59.
well in all seriousness of course there are ‘not good’ bits of bodies on the surface its just that they dont tend to run through an entire population which is surviving quite well, unless of course they are poor selectively bred goldfish that can barely move or 5oz dogs!
i did also notice that luskin actually admits to evolution here, even if its ‘backwards’.
Rey Fox says
“So it seems clear that, by ID logic, the blind organisms can’t have evolved from the sighted ones, as that would be an example of “macroevolution”.”
No, the fish didn’t become donkeys, so it’s still micro. The great impenetrable wall between micro and macro is actually another one of their movable goalposts, if I may mix metaphors wantonly.
I read in Zimmer’s At The Water’s Edge that vestigial eyes are sometimes still good enough to function as sundials. Not that this contradicts in any way what PZ just said here.
CalTech alone is proof of that. I don’t know which is funnier (and weirder): The Great Rose Bowl hoax I and II, catapulting oranges all the way to a local community college, and the Senior day off or whatever it’s called, where the underclassmen go into the seniors’ dorms and, uh, rearrange things. I think one kid took a car apart and reassembled it in someone’s room. And someone else came home to find his door was no longer there–plastered over, and even had working sconces.
Your explanation and destruction of Luskin’s argument was great and made more sense to me now that I read the book “your inner fish” by Shubin.
The book is written in a very accessible manner and even the fellows at the DI should follow it.
ID : “We don’t know how this happened, ergo
God Did Itthere must have been a designer behind it”
It’s the ultimate argument from ignorance, most often practiced by the ignorant.
pz, your article is much, much better than hitchens’ article.
for one, you’re a biologist. so your explanation makes sense and is scientifically grounded. hitchens sounds a bit like any other mostly-uninformed message board member, and then has the audacity to try to take credit for an argument i’ve heard at least a dozen times. not especially new AND arrogant. and it doesn’t cover the very basic fact that your article explains:
loss of features IS new “information.” old genes for the complete structures are still in place, and it’s NEW genes that have evolved to switch those genes off. same with just about every other secondarily-lost feature.
@ PZ myers and other biologists:
I remember hearing that in chickens the gene that regulates some aspect of mandible(jaw) morphology also negatively correlates with length of limbs(and this has been demonstated)
anyway i remember hearing it said that the gene in question explains why T-rex arms are so tiny/ and conversely why the aspect this gene positively regulates explains why even pelican’s have a change in beak morphology instead of expansion of mandibular shape to compensate for both the need of flight and the ability to change the size of their mouth accessories.
It seems resonable to expect that there would be a strong selective pressure to remove eyes from cave-dwelling animals – rather than any kind of advantage, to an animal living in perpetual darkness an eye is just a very soft, sensitive part of the nervous system, exposed to an indifferent environment with lots of sharp, pokey corners.
This is not the case in the benthic zone, where there are few things to run in to, and finding food and mates is presumably a more pressing problem. I don’t know the numbers, but it seems to me that there are a lot more bioluminescent forms among ocean-dwellers than troglodytes.
What, no Fr. J or Sandi here to stick up for gawd? Now I’ll have to settle for some nice cold watermelon instead of troll steak. Dang.
Sonic Hedgehog (Shh) is the best (well, for me, second best really)! My lab has found that Shh also interacts with the Rb/E2F cell cycle pathway in regulating brain development. This gene does so much. It’s very cool.
Yes, it is a cool name too. I have a dream that I will discover a new gene myself so that I can name it something awesome.
Oh yes, and I concur that IDiots are, well, idiots.
Try reading the whole paper. It’s about the genetic mechanism for evolving novel morphology – Cis or Trans. Hoekstra and Coyne have nothing against positive selection for trait loss, pleiotropy, or any of the other big ideas. Creotard trolls are great at looking at the abstract of this one and not wading through the many many pages of nuanced arguments therein.
Re positive selection for eye loss – not only is there no cost for losing eyes in the dark, it also loses cave dwellers a fantastic orifice for collecting irritants, parasites, and infections. In the absence of vision being an advantage, lack of eyes can be a lot more fit than presence of eyes.
craig @ #25
I never read the paper but in Lake Washington stickleback fish lost their pigmentation in about 55 yrs. Cleaning up the pollution in the lake upped visibility considerably, probably causing the change. I read about it in the seattle times.
Catherine Peichel, May 20, 2008 Current Biology
Jesus Christ…is there anything Sonic Hedgehog DOESNT do?!
No Andrew, there really isn’t (re. #100)
Nice refutation of it all. Though it’s like shooting fish in a barrel.
Come for the crackers, stay for the lernin’. :) Excellent article!
In that one quoted paragraph they admit that evolution exists and just don’t realise they’ve done it. Random mutation and natural selection exist. They provide advantageous change, even if that change is ‘backward’ or less complex.
And, whoops, that change isn’t less complex! It’s a novel genetic suppresion!
So ID is now only claiming that (positive, novel) mutations can’t or don’t exist? Is that all ID is now? Can we get that in writing from the DI? And then rub their noses in some science? (I mean, more then we already do?)
also, #81: HA!
Technically this is a misnomer, as the Vampyromorpha are neither squid nor octopi, but in their own Order. And are way cool.
Shh: Sonic Hedgehog
That has got to be the coolest name for a gene…
Its interesting to know that evolution also removes some things which because you seem to have it…redeems importance!
Steven Sullivan says
Sonic Hedgehog? As far a silly gene names go, bah, that’s nothing. I take it you’ve never heard of Shaven Baby?
The whole Sevenless/Son of Sevenless/Bride of Sevenless family? Lunatic Fringe?
Fly geneticists is the craaziest people.
I think I would prefer the analogy:
That might be fun to see.
i want a functional appendix back, goddamn it. or is that god damned it.