Our interaction with Karl Giberson about human “tails” has reached the tail end of whatever interest it held. Writing once more today at The Daily Beast, he dismisses Casey Luskin’s voluminous citations of medical research in a series of posts (see here). Casey’s presentation lead to the conclusions that

• No babies are born with perfectly formed, fully functional tails.
• Babies that do have tails typically have serious associated neurological defects.
• The exact causes of tails are debated, but because of their persistent association with neurological defects, the most plausible view is that they result from abnormalities and deviations in development.

Giberson now tries to change the context of the disagreement. In his debate with Stephen Meyer, where Dr. Giberson displayed for the audience a Photoshopped image of a baby with a computer-generated “tail,” and failed to acknowledge it as such, Giberson was talking about tails as evidence of common descent from a tailed ancestor.

“The baby can be born with a tail like this,” he told the audience in Richmond, VA. And: “This again I think provides the sort of very compelling evidence that common ancestry should be understood as a simple fact.”

Switching gears, as of today he says, “I gave some examples of bad design and showed a picture of an infant with a well-formed tail to illustrate one example.”

“Bad design” is a perennial criticism aimed at the theory of intelligent design, but it’s a distinct issue from the question of common descent. If you want to use “tails” as evidence for common ancestry, you need to confront the mountain of counterevidence that Casey presents. Giberson hasn’t done that.

Nor does he address my questions of last week about whether he’s used the phony tail photo in the past, how often has he done so, did it ever occur to him it might have been digitally manipulated, why did he choose it over authentic “tail” photos that by no means look “well formed,” and will he desist from using it in the future?

He does say that “where the image came from is of zero import; Klinghoffer’s point does absolutely nothing to undermine the universally accepted and fully documented reality that human babies are occasionally born with tails.” Where he got the photo is indeed of less “import” than the fact that it is manufactured. No baby was ever born with a computer-generated tail.

This is a pretty disappointing response from Dr. Giberson, made more so by his repeated ad hominem insinuations. He harps on the fact that Casey (besides having a graduate degree in earth science) has a background as an attorney, as if being a lawyer itself detracts from your credibility. Dr. Giberson doesn’t say what it is in his own profession as a physicist that makes him a more believable interpreter of medical evidence.

He has also now twice alluded to our being “paid” — referring to the fact that Casey and I are both on staff with an organization, Discovery Institute’s Center for Science & Culture, that supports research and advocacy on intelligent design.

Giberson doesn’t indicate why that invalidates what we say, whereas his own past work, having served as salaried staff for the pro-theistic evolution BioLogos Foundation, never called into question his integrity as a theistic evolutionary advocate.

For goodness sake. I think that’s enough of Karl Giberson for now.

I’m on Twitter. Find me @d_klinghoffer.