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).

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.

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.

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.

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

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.

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.

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?