The Discovery Institute's latest attack on the PBS Evolution series provides a remarkable glimpse of the actual caliber of the scientific "evidence" they claim to have developed against Darwin. In a single paragraph in one of their press releases, they accused the series of having made three important "factual errors" in support of Darwin's theories. A close look at their criticisms, however, shows that it's the scholars of Discovery Institute, not PBS, who have just gone 0 for 3.
Strike 1:
"Evolution" . . . makes numerous factual errors that exaggerate the evidential support for Darwinism. The series asserts that the universality of the genetic code establishes that all organisms had a common ancestor. But biologists have known for well over a decade that the genetic code is not universal.Wrong. The genetic code is indeed universal. If it weren't, genetic engineers would not be able to swap genes between organisms as different as humans, insects, bacteria, and yeast and still have them work. For better or for worse, gene swapping does work and it works brilliantly. So, how did the Discovery Institute decide that the code is "not universal?" It turns out that in some organisms, a few of the 64 possible "words" of the genetic code are different. Do a few different words mean that the code is not universal? Only if you're willing to say that the US and Britain don't share a common language because elevators in the UK are called "lifts" and they spell the word "color" with a "u."
It gets better. These slight differences in the code actually support the Darwinian concept of a universal common ancestor. This was a point made by Princeton University researchers Robin D. Knight, Stephen J. Freeland and Laura F. Landweber in an article earlier this year ("Rewiring the Keyboard: Evolvability of the Genetic Code," ," Nature Reviews - Genetics. 2: 49-58 (2001)). Incredibly, the Discovery Institute, which cited this very paper in their "Viewer's Guide" to the PBS series, actually wrote:
It is now clear that the genetic code is not the same in all living things, and that it does not provide 'powerful evidence' that all living things 'evolved on a single tree of life.When Professor Laura Landweber, the senior author on this paper, read the Discovery Institute's analysis of differences in the genetic code, she minced no words. Prof. Landweber wrote:
That is indeed a horrible misinterpretation, because it is clear, particularly in the tree in our paper and in others, that each nonstandard code is a subtle derivative of the standard genetic code and that all codes are derived from it.In plain language, when these "subtle" differences in the code are examined, they actually provide powerful evidence in favor of evolution. Not only was PBS right, but, if anything, they understated the extent to which the genetic code supports Darwin's theory. The status of this scientific "evidence" against evolution? According to Prof. Landweber, it's nothing more than a "horrible misinterpretation."
Strike Two:
Brown University biologist Kenneth Miller asserts that the "imperfect" wiring of the vertebrate retina proves that natural selection, not an intelligent designer, produced the eye. God, in Miller's opinion, wouldn't have done it that way. To arrange the retina as Miller thinks best, however, would render it inoperative.In the first show of the PBS series I pointed out that the light sensitive portions of the photoreceptor cells of the vertebrate retina are not positioned optimally to face the incoming light. Instead, they are placed beneath the neural wiring of the retina. This arrangement cannot be explained in terms of intelligent design, but is perfectly understandable in light of evolution. The vertebrate retina evolved as an outgrowth of the brain, and as a result its neural wiring retains its original arrangement, scattering the incoming light before can be sensed by the photoreceptor cells.
One can argue whether or not "God would have done it that way," but on one point there can be no dispute. The Discovery Institute is dead wrong when it says that the retina would be "inoperative" if it were arranged with the neural wiring beneath a layer of light sensing cells. How can we be so sure? Because that's exactly how the eyes of many mollusks are arranged. It will, no doubt, come as a great surprise to squid everywhere that, according to the Discovery Institute, their eyes don't work!
Strike Three
Beauty may indeed be in the "eye of the beholder," but is there any excuse for criticizing a statement that was never made? The third charge made by the Institute press release was that PBS had implied that researcher Dan-Eric Nilsson had written a "computer program" that simulated the evolution of the eye:
The series leaves the distinct impression that a computer program has successfully simulated the evolution of the eye. But such a program nowhere exists " a fact recently verified by Professor Dan Nilsson (of Lund University in Sweden), the very expert that PBS interviewed about eye evolution.It's not at all surprising that Prof. Nilsson "verified" the non-existence of such a program, since the PBS series never claimed that such a program existed in the first place. Here are the exact words from the broadcast:
Narrator: "At the University of Lund in Sweden, zoologist Dan-Eric Nilsson has developed models to show how a primitive eye-spot could evolve through intermediate stages to become a complex human-like eye in less than half a million years."Not once does the PBS program refer to or even imply the existence of a "computer program." Where did the "distinct impression" come from? It's impossible to say, and I would hope that at some point our friends in the Discovery Institute would explain the thought process that led them to write a press release complaining about a statement that was never made.
Nilsson: "I've been interested in eye evolution for a long time, and in particular I've been interested in the question of how long a time it would take for an eye to evolve."
Narrator: "Nilsson envisioned a sequence of stages by which a flat patch of light-sensitive cells on an animal's skin could evolve into a camera-type eye. As a first step, nature would favor any changes that made the flat patch more cup-like."
The Discovery Institute's Box Score: 0 for 3
The Discovery Institute has complained repeatedly that PBS, as well as mainstream science, has ignored powerful evidence against Darwin's theory. Unfortunately, when given a chance to say just what that evidence might be, they have consistently struck out. Those three "factual errors" in the PBS series? They actually come from the Discovery Institute's own "horrible misinterpretation" of genetic code data, their lack of knowledge of the mollusk eye, and their comically overactive imagination.
Just like Darwin, and unlike the Discovery Institute, PBS got it right the very first time.
Kenneth R. Miller
Professor of Biology
Brown University
Providence, RI 02912
October 3, 2001
