Pharyngula

I tell other scientists all the time that their work is being appropriated by creationists who barely understand it, and that it is getting distorted to support bogus pseudoscience. Whenever you see a creationist quote a genuine science paper, you can pretty much trust that it is going to be mangled beyond recognition.

For instance, Jonathan MacLatchie raised a peculiar collection of questions to grill me with; here’s one of them.

9) If, as is often claimed by Darwinists, the pharyngeal pouches and ridges are indeed accurately thought of as vestigial gill slits (thus demonstrating our shared ancestry with fish), then why is it that the ‘gill-slit’ region in humans does not contain even partly developing slits or gills, and has no respiratory function? In fish, these structures are, quite literally, slits that form openings to allow water in and out of the internal gills that remove oxygen from the water. In human embryos, however, the pharyngeal pouches do not appear to be ‘old structures’ which have been reworked into ‘new structures’ (they do not develop into homologous structures such as lungs). Instead, the developmental fate of these locations includes a wide variety of structures which become part of the face, bones associated with the ear, facial expression muscles, the thymus, thyroid, and parathyroid glands (e.g. Manley and Capecchi, 1998).

You might be wondering about what that paper actually says, and you should. Never trust a creationist! And here’s where I get to pull Marshall McLuhan into the frame from offscreen.

Nancy Manley of the University of Georgia wrote to me today.

As a fan of both your website and of the pharyngula stages of development, I was intrigued to see the questions posed to you by ID followers before your recent talk. And kind of surprised, and bit taken aback, when one of my postdoctoral papers was cited in one of the questions – I am the Manley of Manley et al.

Since the ID questioners used a reference to one of my papers in the question, and this is actually an issue I am personally interested in from a scientific point of view, I feel compelled to answer also. In a way, it is ironic that they used this paper to illustrate their question, since it was our analysis of the pharyngeal pouch phenotype of the Hoxa3 null mice that led to our own interest in why terrestrial animals don’t have gills, and how the thymus and parathyroids may have evolved. We hypothesized that the evolution of morphology in the pharyngeal region (i.e. loss of gills and gain of pouch-derived organs like the thymus and parathyroids) was due to changes in the expression and/or function of the Hoxa3 gene. This hypothesis was proposed in a book chapter that I co-authored (Manley, NR and CC Blackburn. Thymus and Parathyroids. In Handbook of Stem Cells, Vol. 2: Embryonic Stem Cells, R. Lanza (Ed). Academic Press, 2004 v. 1:pp 391-406). I even obtained an NSF grant (now defunct) to test this hypothesis, and recently published a paper in the Proceedings of the National Academy of Sciences about it (Chen, et al., 2010, PNAS 107(23):10555-10560). We haven’t solved the problem yet, but the data so far indicate that changes in both the expression and function of Hoxa3 may have been involved in the evolution of pharyngeal region derivatives during vertebrate evolution, including loss of gills and development of pharyngeal pouch-derived organs.

I wish I could magically pull scientists out of a hat every time some po-faced creationist stooge raises a hand at one of my talks and starts lecturing me on their memorized quotes from the scientific literature. They always get them wrong.


By the way, I’ve been playing a game with MacLatchie. Every time I look into one of his citations, I go to google and type in both the author’s name and that of Harun Yahya, the Turkish creationist. It’s amazing — every time, I get a couple of quotes from one of his books, and they’re almost exactly the same as MacLatchie’s comments.

For example,
Harun Yahya also cites Manley. Compare this with what MacLatchie wrote, above.

Those human emryonic “gill slits” are just another Darwinian myth. These pharyngeal pouches do not develop into homologous structures such as lungs or gill-like structures. The developmental fate of these pouches include a wide variety of structures that become parts of the face, ear cavities, bones of the middle ear, muscles of masticulation and facial expression, the lower jaw, certain neck parts, and the thymus, thyroid, and parathyroid glands. (Manley, N.R. and Capecchi, M.R., Developmental Biology, 195 (1):1-15, 1998)

Isn’t this just weird? Now Yahya is a notorious plagiarist who rips off everything he’s written from the Christian creationist literature, and I don’t think MacLatchie is getting it from him. On the other hand, MacLatchie is a nobody, so I don’t think Yahya stole it from him. I think there’s another creationist source book somewhere, which both are borrowing from to make their claims, and I’m itching to know what it is.

The one thing I know for sure is that neither MacLatchie nor Yahya are at all original or creative, and that both are just trained parrots echoing some other source. If anyone recognizes where these claims are coming from, let me know — I’d like to go straight to the original compendium of nonsense and prune it at the root.