This eye saw 400 million years ago

September 26, 2009 • 5:48 am

Hollardops eye

I saw this photo on my Facebook page and was transfixed. It was taken by Stephen Marley, who gave me permission to post it here (the image is under his copyright).  As he said on FB:

“This is a type of eye called schizochroal, photographed on a Devonian trilobite Hollardops mesocristata (there are two other major trilobite eye types and literally thousands of individual lens configurations at the species level). What’s really cool about this specimen is that the individual calcite lenses have been preserved with some sort of iron oxide, which makes them clearly stand out from the rest of the dark exoskeleton.”

Steve added later that this specimen dates from 409-394 mya and is from the Atlas Mountains of Morocco.

If you have a serious interest in evolution, you must read about trilobite eyes. They represent the first evolutionary appearance of a compound eye, and their construction and diversity are stunning. Unlike the compound eyes of insects, trilobite eyes were hard, as they were composed of the mineral calcite (calcium carbonate).  As Richard Fortey quipped, this gives new meaning to the term “stony gaze.”

A good introduction to trilobite eyes is this site.  It’s short, but if you don’t have the attention span at least check out the photos.

And here is a paper with an irresistible title, and some even weirder photos, “A Devonian Trilobite with an Eyeshade”, by Richard Fortey and Brian Chatterton.  Fortey is a paleontologist, but also a great science writer whose books have not gotten the attention they deserve on this side of the pond.  He’s the author of Trilobite!, a popular book on the beast that I recommend highly.

Note:  Accessing the Fortey and Chatterton paper might require a subscription, so I’ll post the picture of the “eyeshade” trilobite eye below. It’s also from a Devonian fossil collected in Morocco, and the authors claim that these bizarre columnar eyes allowed the beast a full 360-degree view of the sea floor around it. The “eyeshade,” or overhanging lip on the top of the eye, supposedly prevented overhead light from striking the eye (see demonstration in D and E below).

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Fig. 1. “Eyeshade” eye from Fortey and Chatterton paper.  Here’s their caption: Erbenochile erbeni (Alberti). Devonian (Emsian) Timrahrhart Formation (Jebel Gara el Zguilma, near Foum Zquid), southern Morocco. (A) Posterior view showing overhanging eyeshades. (B) Lateral view. (C) Dorsal view. The headshield is 32 mm across. (D) Side view detail of right eye showing lenses under optimum illumination, and (E) how the eyeshade cuts out light from above, when directed as a parallel beam above the palpebral lobe.

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Preparation and photography of H. mesocristata (from SM): “This specimen was prepared by Mike Thomas using skillful application of micro air-abrasive techniques to preserve the delicate details. The photo was taken with a 55mm micro-Nikkor lens on a 35mm “film based” Nikon F2 Camera using a fiber optic illumination system. The 35mm film was scanned at 2400 dpi on a Imacon Flextight scanner and converted to a jpeg file. The eye measured 8.5 mm horizontally.”

Thanks to Steve for permission and information.

Feathered dinos older than Archaeopteryx fulfill an evolutionary prediction!

September 25, 2009 • 9:24 am

One of the puzzles in the evolution of birds from theropod dinosaurs appears to have been solved, at least according to this BBC report (I haven’t yet read the paper, which hasn’t been published).  The discovery of pre-Cretaceous feathered dinosaurs fulfills a prediction that I — and of course many others — have made about what the fossils should show about the temporal existence of feathered dinos.   The transitional “bird-lizard” Archaeopteryx had fully-formed feathers, but all of the feathered dinosaurs found in the last few years have been younger than Archaeopteryx.   This leaves a gap, since the oldest transitional form already has well-formed feathers.

On p. 44 of Why Evolution is True I say this:

“All these nonflying feathered dinosaur fossils date between 135 and 110 million years ago — later than the 145-million-year old Archaeopteryx. That means that they could not be Archaeopteryx‘s direct ancestors, but they could have been its cousins.  Feathered dinosaurs probably continued to exist after one of their kin gave rise to birds. We should, then, be able to find even older feathered dinosaurs that were the ancestors of Archaeopteryx.  The problem is that feathers are preserved only in special sediments — the fine-grained silt of quiet environments like lake beds or lagoons. And these conditions are very rare.  But we can make another testable evolutionary prediction: someday we’ll find fossils of feathered dinosaurs that are older than Archaeopteryx.”

I am chuffed to report that that day is TODAY!  A group of paleontologists from China have announced the finding of several species of feathered dinosaurs (including a “four-winged” version) that are ten million years older than Archaeopteryx.  This is a wonderful discovery, and a fulfillment of an evolutionary prediction as strong as that made by Neil Shubin, who predicted, and found, tetrapod transitional forms in Canadian rocks of exactly the right age.

Oh, and here’s another prediction:  we will some day find dinosaurs with even more rudimentary feathers than the ones described today, and these fossils will be around 160 million years old.

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Fig. 1.  One of the new feathered dinos, Anchiornis huxleyi (photo from BBC website). Download the paper (see bottom of post) for graphic interpretation of the fossil.

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Fig. 2. Reconstruction of one of the dinos with feathers on fore- and hindlimbs. (From BBC website).

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Update:  The paper is indeed online, and you can download it here as a pdf file.

Hu, D., L. Hou, L. Zhang, and X. Xu. 2009. A pre-Archaeopteryx troodontid theropod from China with long feathers on the metatarsus. Nature 461:640-643.

h/t: Greg Mayer

Kirk Cameron and Kevin Padian on the creationist Origin

September 25, 2009 • 7:54 am

Well, I hate to steer you to People magazine, but that’s where there’s a piece on Cameron and his “new edition” of The Origin (see my previous post here).  The piece is fairly ho-hum except for two things.  First, while it links to Cameron’s own promotional video, it also links to two “spoof” videos, including the one by Christina from Romania. I’d say that’s decent balance in reporting.

Second, there’s an interesting comment by Berkeley paleontologist Kevin Padian:

But academics dismiss such arguments [Cameron’s equation of Darwin with Hitler] as ludicrous.

“This has been refuted many, many times. The anti-evolutionist fearmongers have to link Darwin to every perceived evil from mankind,” says Kevin Padian, professor of paleontology and evolutionary biology at the University of California, Berkeley. “The two kinds people who believe that religion and evolution can not coexist are extreme atheists and extreme religious fundamentalists. Everyone else doesn’t really have a problem. [A majority] of Americans believe that a belief in god is compatible with evolution.”

Well, good for People to seek at least one dissenting voice, and Padian’s first sentence is on the mark.  But look further, as he equates “extreme atheists” (does he mean atheists who speak up?) to “extreme religious fundamentalists.”

Padian, of course, is President of the National Center for Science Education.  Did he really need to sneak in an anti-atheist crack like that?

It is now beyond doubt that the NCSE has a strategy, official or not, to marginalize and denigrate atheists, despite the fact that many of their officers (and members!) are unbelievers. Bad on them; very bad.  They have chosen to coddle believers in a way that alienates the rest of us. This is not a winning strategy, nor one that’s going to jack up the proportion of Americans who accept evolution.

Southwestward Ho

September 25, 2009 • 7:04 am

For the next two weeks or so (until Oct. 15), I’ll be traipsing through the wilds of California and Guatemala.  First to Los Angeles, where the Otter and I will take off for a camping interlude in one of my favorite places, Death Valley.  Then it’s off to the Atheist Alliance International conference from Oct. 2-4, where I’ll be speaking along with other apostates like Richard Dawkins, Daniel Dennett, Russell Blackmore, P. Z. Myers, and (this should be interesting) Bill Maher.  I will try to post from the meeting, but you can absolutely count on P.Z. for on-the-spot reporting.

After that, I’m off to Guatemala to give two talks (one on the problem of creationism and the other on the evidence for evolution) at Universidad Francisco Marroquín (UFM), a private university in Guatemala City.  A perk here is that I’ll have an extra ten days to see that wonderful country, which I haven’t visited since 1973.  My goal — beyond interacting with the folks at UFM — is to spot some nice birds (especially the male resplendant quetzal, the world’s most beautiful bird), soak up what culture I can in that short time, and visit some spectacular Mayan ruins like Tikal.

I will try to post sporadically during my absence, but my blogging buddies Greg Mayer and Matthew Cobb have promised to fill in for me until the 15th.

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Fig. 1.   Pharomachrus mocinno, here I come!

Coyne vs. Wright, Reader’s Digest version

September 24, 2009 • 2:15 pm

As I promised a while back, I  provided a long answer to Robert Wright, who criticized me on his website for supposedly misrepresenting his views in my review of his book, The Evolution of God, in The New Republic.

A much shorter give-and-take has just been published in The New Republic itself, which you can find here (n.b.: there are two pages).  Note that Wright threatens further “corrective comment,” but I am done.

Hall of Shame

September 24, 2009 • 10:22 am

Quote of the week, from the personal website of the Public Information Project Director of the National Center for Science Education  (speaking unofficially, of course):

If the goal of this blog is to be at all educational, one hopes that a vigorous defense of of analogy will serve some salutary effect in the difficulties people have with analogical thinking, whether they be religious fundamentalists bent on Biblical literalism, or atheists bent on insisting that literalism is the true form of religion.

Comment: I weep for the NCSE if this kind of idea is running the railroad.  We atheists don’t give a tinker’s dam about what the true form of religion might be, because we don’t think there is one! Nor do we have one.  We don’t worship Darwin, nor think that he’s infallible.  Is this part of a strategy to marginalize atheists along with Biblical fundamentalists?

Rosenhouse, Benson and Blackford on Sullivan on evil

September 23, 2009 • 12:05 pm

Jason Rosenhouse, Ophelia Benson, and Russell Blackford have chimed in on the discussion (which Russell actually started) of Andrew Sullivan’s theodicy.

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Update:  Sullivan battles back in two posts on The Daily Dish (see links and my response in the comments to this post).  But, like a hooked fish, he’s getting weaker as he fights. And Jason has sunk another hook here.

A creationist edition of The Origin

September 23, 2009 • 7:46 am

If you’ve been around the blogosphere of late, you’ll know that Kirk Cameron and Ray Comfort, those creationists of the-banana-proves-God fame, are issuing their own edition of On the Origin of Species, in a run of 50,000 copies, in time to “subvert” Darwin Day (their target date is Nov. 22, but Darwin’s book actually appeared on Nov. 24, 1859).

The book is apparently just a reprint of The Origin, which is out of copyright, with a 50-page copyrighted introduction by Ray Comfort. You can download the introduction on The Huffington Post page by clicking on the pdf link.  Since we’ve all read Darwin, you don’t need to get the book; you can just read the free intro.

The introduction is notable for two things.  First, its intellectual vacuity.  That’s nothing new for creationist tracts, but this intro is a lot closer to Gish and Morris than to Dembski and Berlinski.  Apparently Comfort and Cameron haven’t really absorbed all the “new” creationist arguments against evolution: they simply repeat the old canards about the lack of transitional forms (incuding — God help us — Piltdown Man), the irreducible complexity of complex organs (but of the eye, not biochemistry!), and the fact that “random chance” simply couldn’t produce organisms.  There’s no mention of the “fine-tuning” of the universe.

And the introduction is rife with out-of-context quotations.  Once again, Darwin’s quote on the difficulty of seeing how the eye evolved gradually is trotted out (with his response omitted, as usual), and Steve Gould’s punctuated equilibrium is used to imply that organisms appeared suddenly, without ancestors.  Unsurprisingly, Francis Collins pops up, emphasizing his take on the DNA code of humans: “I can’t help but look at those pages and have a vague sense that this is giving me a glimpse of God’s mind.”  (Note: this quote is NOT out of context. You don’t need to selectively quote Collins to find words that give succor to creationists.)

If you’re looking for new creationist arguments, you won’t find them here.

Second, the introduction is funny.  Not intentionally funny, but funny in its single-minded religiously-based stupidity.  Toward the end of the introduction, for instance, Comfort gives up any pretense of discussing evolution and simply lapses into straight evangelical preaching.  Are you saved? If not, you’ll burn in the fires of hell for sure. And the only way to be saved is to accept Jesus. . . yadda yadda yadda.   One of the funniest parts is on pp. 46-47, where Comfort considers four major religions: Hinduism, Buddhism, Islam, and Christianity.  Which of these will bring you eternal salvation?  You guessed it.  But it’s not a fair fight, because Comfort assumes from the outset that the tenets of Christianity are correct. If you buy that, then of course doing what Muhammad tells you won’t save you from an eternity in molten sulfur.  Here’s a snippet about Islam:

Islam: Interestingly, Islam acknowledges the reality of sin and Hell, and the justice of God, but the hope it offers is that sinners can escape God’s justice if they do religious works. God will see these, and because of them, hopefully He will show mercy—but they won’t know for sure.  Each person’s works will be weighed on the Day of Judgment and it will then be decided who is saved and who is not—based on whether they followed Islam, were sincere in repentance, and performed enough righteous deeds to outweigh their bad ones.

So Islam believes you can earn God’s mercy by your own efforts. That’s like jumping out of the plane and believing that flapping your arms is going to counter the law of gravity and save you from a 10,000-foot drop.

But back to Comfort’s “scientific” attack on evolution.  Here are his arguments:

1. “Mindless chance” can’t produce complex organisms. Of course not; none of us ever said it could.  But natural selection is not “mindless chance”; it’s the antithesis of it. Surely these people have read Dawkins.  If they have, they’re duplicitous.  If they haven’t, they’re willfully ignorant, and that’s duplicitous too.

2. Similarities of DNA don’t prove common ancestry, just the common “plan” of God. I’ve thought of this argument myself, because it’s so obvious; and that’s why I didn’t use DNA similarities as evidence for evolution in my book.  Nevertheless, the creationist argument is wrong here, but for a subtle reason. Yes, you could claim that the similarity of DNA between hippos and whales reflect a fundamental “mammality” that goes along with their common plan of having lungs, homeothermy, milk glands, etc.  But what refutes this argument is the observation that nonfunctional DNA (including non-coding nucleotides and pseudogenes) gives the same set of similarities as does functional DNA!  It’s hard to understand how genes that don’t produce a product, and therefore can’t function in building an organism, will be more similar between whales and hippos than between whales and, say, fish.  Creationism offers no explanation, but evolution does.  Richard Dawkins has a wonderful discussion of the molecular-similarity issue in The Greatest Show on Earth.

3.  There are no transitional fossils. This is the dumbest argument of all given the profusion of such forms found in the last three decades, including transitional fossils showing  whale evolution, bird evolution, and tetrapod evolution.  These are either ignored or dismissed as reflecting God’s plan.  A lot is made of Piltdown Man (no mention, of course, that the hoax was revealed by scientists) and of the fake dino-bird Archaeoraptor, which turned out to be a forgery, but not before it was touted as a transitional form by National Geographic. (Again, the fraud was quickly caught by scientists.)

The early primate Ida (Darwinius) appears, along with a breathless statement by David Attenborough implying that she was a human ancestor and the predictable response that evolutionists were fooled again.  But within a day after the fossil was announced, scientists quickly weighed in proclaiming that Darwinius was probably not our ancestor, but an early, lemur-like creature that probably left no descendants.  Comfort discusses none of this, but are you surprised at this intellectual dishonesty?

4.  Transitional forms could not evolve by natural selection (i.e., there could not be a selective advantage of intermediate forms).  Much is made of why both blood and the circulatory system must have been simultaneously created because neither would function without the other.  No discussion, of course, about how blood and its vessels might have coevolved, or how a precursor of blood could function in a coelom without vessels. And even the eye shows up, an organ for which Darwin already showed, in The Origin,  a plausible series of intermediate stages.  Instead, Comfort says this:

The eye is an example of what is referred to as “irreducible complexity.” It would be absolutely impossible for random processes, operating through gradual mechanisms of geneti mutation and natural selection, to be able to create forty separate subsystems when they provide no advantage to the whole until the very last state of development. Ask yourself how the lens, the retina, the optic nerve, and all the other parts in vertebrates that play a role in seeing not only appeared from nothing, but evolved into interrelated and working parts. Evolutionist Robert Jastrow acknowledges that highly trained scientists could not have improved upon “blind chance”. . .

Well, they could have had the decency to update this argument and use Intelligent Design examples of blood clotting or immunology, which sound more plausible to the layperson.  After all, if you read the book itself, you’ll see Darwin himself refutes what Comfort says in the introduction.

5. Vestigial organs say nothing about evolution because they might be of some use. This is a common argument, but it misses the point: vestigial organs show evolution because they are understandable only as holdovers from ancestors.  Whether the vestigial kiwi wing has a use or not (and I seriously doubt that it does!) does not refute the argument that this tiny nub is the remnant of the wing of its flying ancestors.

That’s the gist of what little “science” is adduced here.  And just to make sure that evolution is properly smeared, Comfort also brings up Hitler’s “Darwinian” views on selective breeding, and presents a few statements of Darwin about the inferiority of women and blacks.  (There is no mention of Darwin’s ardent anti-slavery activities.)  Yes,  Darwin was a man of his times, and showed some racism and misogyny, but that doesn’t disprove evolution!  We could turn this argument on its head, of course, and say that the Inquisition disproves Christianity.

Since we’ve been discussing theodicy, it’s appropriate that Comfort’s peroration is about the goodness of God.  But he unintentionally shows that God isn’t so good after all.  On pp. 43-44 you can read this:

To say that there will be no consequences for breaking God’s Law is to say that God is unjust, that He is evil. This is why.

On February 24, 2005, a nine-year-old girl was reported missing from her home in Homosassa, Florida. Three weeks, later, police discovered that she had been kidnapped, brutally raped, and then buried alive. Little Jessica Lunsford was found tied up, in a kneeling position, clutching a stuffed toy.

How Do You React?

How do you feel toward the man who murdered that helpless little girl in such an unspeakably cruel way? Are you angered? I hope so. I hope you are outraged. If you were completely indifferent to her fate [ed: like God apparently was!], it would reveal something horrible about your character. Do you think that God is indifferent to such acts of evil? You can bet your precious soul He is not. He is outraged by them. The fury of Almighty God against evil is evidence of His goodness. If He wasn’t angered, He wouldn’t be good. We cannot separate God’s goodness from His anger. Again, if God is good by nature, He must be unspeakably angry at wickedness.

What angers me almost as much as Comfort and Cameron’s duplicity about science is their slavish worship of a god whose plan called for Jessica Lunsford to be raped and murdered in the first place.

Enough. You don’t have to read this introduction; the theology is as dreadful as the science.

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Update:  Salon takes on Cameron/Comfort here.