Monday, February 7, 2011

A Creationist Examines Human Tails

First, a bit of background. Human tails are an atavism: the reappearance of an ancestral trait in certain individuals after many generations. Atavisms are an important piece of evidence for evolution because they help show how various animal species diverged. In particular, human tails represent the resurgence of the more robust tail of earlier primates. There are other examples of atavisms that I find more exciting than human tails (for example, whale legs), but it's still quite an interesting phenomenon.

Now, a few months ago I found an article by Andrew Lamb on the Creation Ministries International website entitled "Human tails and fairy tales," which disputes information presented in Douglas Theobald's "29+ Evidences for Macroevolution." Theobald discusses instances of "true human tails" containing vertebrae and presents an x-ray from a scientific paper as visual proof.

Lamb, however, claims that the coccyxes of the children described in the paper are in fact perfectly normal:
"In fact that x-ray shows a normal healthy spine, as admitted in the original research paper by Bar-Maor et al. from which that x-ray image (Figure 3 in the paper) was taken."
I was taken aback by Lamb's assertion, and began to wonder if Theobald's excellent article was not as accurate as I had thought. I decided to investigate, and found that in fact Theobald was correct and Lamb was completely wrong. If Lamb read the paper to its conclusion, he should have seen that:
"Our first patient had no obvious coccygeal protuberance, but the coccygeal anomaly was well evident on radiographs as a tail-like structure and was the cause of his coccygodynia. This anomaly could be described in Bartels' traditional classification as 'a bony tail caused by hypertrophy of the sacrococcygeal vertebrae'. Our second and third patients had almost similar radiological findings, but in addition they had soft protuberances."
Does Lamb consider the phrases "coccygeal anomaly," "bony tail," and "hypertrophy of the sacrococcygeal vertebrae" consistent with idea that the three children's coccyxes were normal and healthy? Lamb also comments:
"Alarmingly, despite Child 2's coccyx being normal and healthy, the Bar-Maor paper goes on to say that part of the coccyx was removed during the surgery[.]"
Yes, it would be alarming, wouldn't it… if the paper gave any indication that the child's coccyx was in fact normal.

I'll grant that the paper's use of the phrase "well-developed" to describe the vertebrae could be taken to mean "developed correctly" rather than "over-developed." However, this paper isn't much more than 2 pages long. How could Lamb have missed the entire paragraph quoted above – not to mention a description of one of the coccyxes as "very prominent"?

Perhaps Lamb has expertise in anatomy, and in his professional opinion the x-rays appear normal? Nope. A quick look at his biography page shows that he only has degrees in education and computer science – no such expertise to be found. It's difficult to tell whether Lamb was intentionally deceptive or simply incompetent in his response, but to give him the benefit of the doubt I'll assume the latter.

Through this experience, I gained a fuller understanding of atavistic human tails. But more generally, it really impressed on me the importance of investigating controversial claims, especially when they come from heavily biased sources like CMI.


  1. What do you mean bias? Your not bias? You clearly believe in evolution and hold the position it occurred

  2. Taking a position on an issue is not the same thing as being biased. CMI is biased because they start with a premise—the truth of the Bible—that they absolutely refuse to question. Here's a quote taken from their Statement of Faith:

    "By definition, no apparent, perceived or claimed evidence in any field, including history and chronology, can be valid if it contradicts the Scriptural record."

    CMI refuses to examine their own unsubstantiated belief that the Bible is an accurate source of historical and scientific information. Ergo: biased.