BFB 10. The Case of the Creeping Fox Terrier Clone

While attending a National Science Teachers Association convention in 1987, Gould took the opportunity to examine all of the biology textbooks that were being marketed in the exhibit hall. He found some concessions to the political forces of creationism, but on the whole was pleasantly surprised in this regard. He was much less happy about another trend, this one the fault of the science community itself: these high school textbooks all present a nearly identical story, using the same examples in the same order. Natural selection, for example, is always presented in contrast to Lamarckism, and via the example of the giraffe’s neck; fossil evidence for evolution invariably discusses the horse lineage. Gould would accept the reasoning behind this approach, if it represented a well-honed optimum; but it does not. In fact, he states, the examples are misleading if not downright inaccurate. [He discusses problems with the giraffe neck example in LMC 16, and with the progression of horses in the next essay, BFB 11.] So why are all the textbooks the same, at least when it comes to discussing evolution? The answer, Gould charges, is that textbook writers (as well as writers of popular books on science) copy from one another, changing just enough to avoid copyright infringement; he refers to this as “cloning.” It is encouraged by the recent “big business” nature of textbook publishing, he continues, but it has been going on for decades.

In support of this charge of textbook cloning, he selects an example that is both distinctive and repetitive: the example of a modern animal that is about the same size as Hyracotherium, the small, multi-toed animal that appeared some 60 million years ago and is the ancestor of modern horses. The almost universal measure of Hyracotherium size today is the fox terrier. (Gould states that he was about to write this phrase himself in another essay when he realized he had no idea how big a fox terrier was!) Using a research assistant and his personal library, he tracked down eighty-six similes for expressing the size of this animal, dating back to the formal description of Eohippus by O. C. Marsh in 1974. (It turns out that the same animal, under the different name of Hyracotherium, had been identified from fragments by Richard Owen in 1841. Gould prefers Owen’s name Eohippus, meaning “dawn horse,” but under the rules of naming organisms discussed in BFB 5, Hyracotherium takes precedence.) Marsh identified the animal as being about the size of a fox, and many later publications repeat this. In the early 20th century, two alternative animals were proposed: the house cat, and the fox terrier. The latter first appeared in 1904, Gould determined, in a popular article entitled The Evolution of the Horse. The author was Henry Fairfield Osborn, famous vertebrate paleontologist [see BFB 29] and president of the American Museum of Natural History in New York; the article was reprinted as a small book, and remained in print and for sale at the museum for fifty years. Gould uses a quasi-humorous tone to describe the eventual victory of the fox terrier simile over its competition (in Darwinian terms). His point is that cloning occurs. To add injury to insult, he notes that the weight of Hyracotherium has been revised upwards to some 50-55 pounds, while fox terriers weigh in at 15-20 pounds. The cloning of textbook material not only propagates errors; students, he argues, can pick up on the lack of effort and enthusiasm by the authors, and as a result are more likely to lose interest in the subject.