Religious credulity and the recent spate of godly ‘science’

I usually like Cornelia Dean’s science reporting, but this recent collection of book reviews put me off from the opening paragraph. She begins with the tired old claim that “scientists have to be brave” to embrace religion. Malarkey. I’ve never heard a scientist bring up the subject of religion, pro or con, at a scientific conference or associated informal gathering. You can be as devout as you want to be with no risk to your professional career (you may even find yourself an icon for the compatibility of science and religion!), and as for your personal life, being religious in a country in which 90% of the residents self-identify as religious, and in which religiosity has become a defining character of our political leadership, is hard to characterize as boldly bucking a trend. The rest of the review is an exercise in credulity.

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Think before morphing

Oh, good. I saw this WaPo article with a morphing animation of a lemur into SJ Gould, and I was mildly appalled—it’s a very badly done gimmick that doesn’t say anything about how evolution works, and actually grossly misleads the viewer on the morphological transformations that had to have occurred. Fortunately, I don’t have to deepen my reputation as a cranky internet curmudgeon by complaining about it— Carl Zimmer has done it for me.

Transforming grid coordinates is an interesting tool in describing the transformations between forms—D’Arcy Wentworth Thompson did it well—but you need to start with forms you know are linearly related and you’ve got to define and align anatomical features very carefully. Picking random photos of various primates and blending them ain’t it.

Age of the Earth

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Just as a lark and as a little exercise in making HTML tables (and to make clear what one error was in that last post), I threw together this table of the geological time scale, taken from Mayr’s What Evolution Is. I come from that generation of biologists where we were required to memorize the timescale to this level of detail; I’m a bit rusty on the dates now (but these are pretty much the same as what I had to learn in the late 1970s), and I was just realizing that we don’t even mention this stuff in introductory biology anymore.

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Coming to Life

Books from Nobel laureates in molecular biology have a tradition of being surprising. James Watson(amzn/b&n/abe/pwll) was catty, gossipy, and amusingly egotistical; Francis Crick(amzn/b&n/abe/pwll) went haring off in all kinds of interesting directions, like a true polymath; and Kary Mullis(amzn/b&n/abe/pwll) was just plain nuts. When I heard that Christiane Nüsslein-Volhard was coming out with a book, my interest and curiousity were definitely piqued. The work by Nüsslein-Volhard and Wieschaus has shaped my entire discipline, so I was eagerly anticipating what her new book, Coming to Life: How Genes Drive Development(amzn/b&n/abe/pwll) would have to say.

It wasn’t what I expected at all, but I think readers here will be appreciative: it’s a primer in developmental biology, written for the layperson! Especially given a few of the responses to my last article, where the jargon seems to have lost some people, this is going to be an invaluable resource.

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Generic bumps and recycled genetic cascades

How do you make a limb? Vertebrate limbs are classic models in organogenesis, and we know a fair bit about the molecular events involved. Limbs are induced at particular boundaries of axial Hox gene expression, and the first recognizable sign of their formation is the appearance of a thickened epithelial bump, the apical ectodermal ridge (AER). The AER is a signaling center that produces, in particular, a set of growth factors such as Fgf4 and Fgf8 that trigger the growth of the underlying tissue, causing the growing limb to protrude. In addition, there’s another signaling center that forms on the posterior side of the growing limb, and which secretes Sonic Hedgehog and defines the polarity of the limb—this center is called the Zone of Polarizing Activity, or ZPA. The activity of these two centers together define two axes of the limb, the proximo-distal and the anterior-posterior. There are other genes involved, of course—this is no simple process—but that’s a very short overview of what’s involved in the early stages of making arms and legs.

Now, gentlemen, examine your torso below the neck. You can probably count five protuberances emerging from it; my description above accounts for four of them. What about that fifth one? (Not to leave the ladies out, of course—you’ve also got the same fifth bump, it’s just not quite as obvious, and it’s usually much more tidily tucked away.)

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David Prentice’s shoddy stem cell scholarship

A reader sent me copy of a letter that will be published in Science this week, criticizing the dishonest tactics of the anti-scientific adult stem cell “advocates” (in quotes because they aren’t really science advocates of any kind—they’re only using it as an issue to limit stem cell research.) Anyway, it raises the interesting question of who you’re going to believe: scientists with expertise in the issues under discussion, or a flunky for Sam Brownback and shill for the religious right?

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