The Myth of Human "Tails": A Physician and Surgeon's Perspective
Editor's note: For a physician and surgeon's perspective on Casey Luskin's series on human "tails," we asked ENV contributor Michael Egnor (pictured at right). Dr. Egnor is Vice-Chairman, Department of Neurological Surgery, and Director, Pediatric Neurosurgery, at State University of New York at Stony Brook. The notion of such atavistic "tails" as evidence of descent from a common tailed ancestors has been widely circulated by Darwinian evolutionary spokesmen, including Jerry Coyne and, most recently in a debate with Stephen Meyer, Karl Giberson.
Casey Luskin's series is excellent and right on target. Karl Giberson's reference to tails (and webbed feet) is junk science. He presupposes a discredited "ontogeny recapitulates phylogeny" -- don't these guys ever give up even utterly discredited ideas?
I have operated on quite a few children (at least five) with what Giberson, a physicist, would call a "tail." I just removed one of them from a newborn about a month ago. None of them -- and none of the reports in the literature that I know of -- are actual tails. A tail has vertebrae, is a continuation of the coccyx, has developed muscles, nerves and other soft tissues, etc. The appendages described in the literature, and all of the appendages on which I have operated, are dysmorphic mesenchymal tissue, often epithelialized exophytic dermal sinus tracts, that bear a superficial resemblance to a "tail." None have the structure of a tail, even in rudimentary form, and none of the ones I have operated on were attached to the coccyx in the way that a tail is. I don't know what to make of the terms "true tail" and "pseudo-tail" -- I've yet to find a cogent definition, and I don't know of any case report of a genuine tail in a human being.
The most common kind of lesion is an epithelialized sinus tract that is an exophytic appendage associated with a lumbosacral lipoma, which is generally thought to be a disorder of secondary neurulation (a process that is notoriously prone to congenital malformation). The spinal cord is often tethered (>50% of the time). The appendage many contain regions of primitive muscle, fat, nerves, blood vessels, etc., but not vertebrae.
It makes no more sense to call such a congenital malformation a "tail" than it makes to call it an arm or a leg, although normal arms and legs do contain muscle, fat, nerves, etc. There is no reason whatsoever to associate it with any sort of "evolutionary regression" or any such nonsense. Again, these Darwinists really have to let "ontogeny recapitulates phylogeny" go. It's embarrassing.
Again, these lesions aren't vestigial and they aren't tails, any more than they are arms or legs. They are congenital malformations. It also bothers me that these babies are stigmatized a bit by calling them "tails." I have to reassure embarrassed and worried parents that their child isn't some kind of "reversion" to lower animals (some have actually asked me that). A child with a sacral appendage is no more a reversion to an animal with a tail than a child with phocomelia is a reversion to a seal or a child with severe holoprosencephaly (which can be associated with a single midline eye) is a reversion to the mythical Cyclops.
Giberson is just spouting junk science for propaganda purposes, which is the Darwinist M.O.
Photo: Michael Egnor/SUNY Stony Brook.