August 13, 2001
On Friday, July 13, 2001, Phil Johnson suffered a stroke. He is currently undergoing rehabilitation therapy, and hopes to return to his normal activities soon. The following Weekly Wedge Update was in preparation when Phil became ill. It covers recent correspondence between Phil and Richard Dawkins, and concludes with comments from Paul Nelson.
The correspondence begins with Dawkins commenting on questions from the Weekly Wedge Update dated July 9, 2001. Dawkins then directs questions of his own to Phil, who replies. Dawkins then clarifies his position, and Paul Nelson comments.
Date: Tue, 10 Jul 2001 07:35:41 +0100
From: Richard Dawkins
To: Phillip Johnson
> For example, what does it mean not to believe in
> "evolution?" Suppose someone argues that science
> has not discovered how life could have originated in
> the first place, or how the complex animal groups that
> appear in the Cambrian rocks could have originated.
> Exactly why is this position unreasonable? Or, suppose
> someone says that the specific qualities of the human mind
> cannot be explained by the Darwinian mechanism, and
> thus it is reasonable to conclude that the human spirit
> may be a special creation of God. Does that position
> display ignorance of science, or lack of faith in
No, of course I didn't mean either of these things. By 'not believe in evolution' I meant 'not believe that humans and lobsters share a common ancestor'. In other words, I specifically meant people like Phillip Johnson has now confirmed himself to be, but NOT people like Michael Behe and Michael Denton who, unless I am mistaken (please say if you know), would happily accept that humans and lobsters share a common ancestor.
Thank you for answering my lobster question unequivocally and honestly. This really has clarified your position. You are commonly bracketed with Behe and Dembski. You have now shown that actually you have more in common with Duane Gish, Henry Morris and Kurt Wise. No wonder you are so indiscriminate in whom you welcome into your big tent.
From your choice of the word 'phylum' in your answer, may I take it that you would give a firm yes to each of the following supplementary questions (again accepting 'ancestor' in exactly the same usual sense)?
You will understand that I am trying to discover whether, in your answer to my previous question, you chose the word 'phylum' judiciously or whether you could have said the same of more junior ranks in the taxonomic hierarchy such as class, order, family or genus. And I am at the same time trying to discover whether you accept that there is such a thing as a taxonomic hierarchy at all.
Please answer the above five as clearly as you did the lobster question, preferably in public again.
I will address your questions below. Meanwhile, it is your turn to answer a question.
On what basis are you so confident that the hypothetical common ancestor of lobsters and humans is not merely an artifact of evolutionary theory, but actually lived on the earth?
My present understanding is that your confidence is founded upon philosophy, specifically upon your belief in materialism and reductionism. That is what permits you to proclaim "Universal Darwinism," i.e., that something like Darwinian evolution must be the explanation for the existence of complex life even on distant planets, where we can make no observations. Am I correct, or do you have scientific evidence, stemming from your specialized knowledge as a zoologist, that ought to convince someone who does not already share your belief that the existence of this ancestor is a philosophical necessity?
I remind you that we are using the term "ancestor" in its usual sense, so that the hypothetical organism must be the ancestor of humans and lobsters in the same sense that two human distant cousins share a common human ancestor, but with many more generations in between.
The people who merit the full scorn of Richard Dawkins seem to be those who reject the common ancestry theory of Darwinism. As a test case, Dawkins pressed me on the question of whether I believed that if we followed the ancestry of lobsters and humans, we would arrive at a common ancestor of both lines. I answered that I believed such a common ancestor has not been identified and cited this as an illustration of the principle that the common ancestry theory clearly is not applicable to the phyla, however valid it may be within groupings far lower in the taxonomic hierarchy.
Dawkins responded by asking if Michael Behe and William Dembski share my position and pressed me on a list of other examples. Behe and Dembski can speak for themselves. I will say for myself, however, that it is very difficult to separate the common ancestry theory from the "blind watchmaker" mechanism espoused by Dawkins and other Darwinists.
I emphasize that Dawkins and I agreed to use the term ancestor in the usual sense. That being the case, there is no mystery about how grandparents are ancestors of their grandchildren. The mechanism is the normal reproductive process which employs genetic information already available in the grandparent and transmits it in the reproductive act. No influx of information is needed and no new types of organs or body plans need to be created or developed.
If humans and lobsters share a common ancestor in this sense, then there must be a reproductive process which can create from this ancestor the specific, complex, adaptive characteristics of modern humans and lobsters without an influx of information from the outside. The existence of such a powerful, creative, natural mechanism has never been demonstrated. If we stick to what scientific testing can verify, the Darwinian mechanism has never done anything more impressive than the microevolution that has been observed in the finch beak example, or in the development of resistance to insecticides or antibiotic drugs. Cyclical population variations in fundamentally stable species have been observed, but no new body plans or organs have been created.
Date: Tue, 10 Jul 2001 23:03:02 +0100
Subject: Re: Evidence
From: Richard Dawkins
To: Phillip Johnson
I have to be in London from early tomorrow morning for most of a week, and shall not be able to answer your question as fully as I would like. Very briefly, the answer to your lobster question is that it is mostly a matter of the seamless continuum of distance of cousinship (measured in practice by resemblance, nowadays especially molecular resemblance). That is what I was getting at in my series of questions, getting progressively more and more distant within the Chordates. The continuum goes on. Crustaceans turn out to be just that much more distant from us than sea squirts, and still much closer than, say, sponges, which are in their turn much closer than bacteria. The same hierarchy of cousinship appears with different molecules -- independent confirmations of the same tree. The reason we know for certain we are all related, including bacteria, is the universality of the genetic code and other biochemical fundamentals. Philosophical commitment to materialism and reductionism is true, but I would prefer to characterise it as philosophical commitment to real explanation as opposed to complete lack of explanation, which is what you espouse (Dennett's distinction between skyhooks and cranes).
When Phil Johnson sent me this correspondence for comment, I found Dawkinss last message puzzling. Dawkins writes that the reason we know for certain that we are all related, including bacteria, is the universality of the genetic code. But the genetic code is not universal. Since the mid-1980s, dozens of variant codes have been discovered, so many in fact that the National Center for Biotechnology Information maintains a web page listing them:
(For a helpful update to this web page, see the recent excellent review by Knight et al., 2001.)
Now Dawkins might reply Oh, dont be a pedant the genetic code is nearly universal, and these are only minor variants, but of course that would give away the game. If the theory of common descent predicts that the code should be universal indeed, Dawkins himself has called this a near-conclusive proof of the theory (1987, 270) but non-universality turns out to be the case, then, by strict logic, something is wrong with common descent.
Yet predictions, theories, and evidence can have a curious relationship with each other. As it happens, common descent sailed right past the discovery of the non-universality of the code. In a recent article (2001, R63-R66) the molecular biologist Niles Lehman surveyed the consequences for evolutionary theory of the discovery of non-universality:
Once thought universal, the specific relationships between amino acids and codons that are collectively known as the genetic code are now proving to be variable in many taxa. While this realization has been disappointing to some the genetic code was often hailed as the ultimate evolutionary anchor in that its universality was perhaps the indisputable piece of evidence that all life shared a common ancestor at some point it has also opened up a rich field of evolutionary analysis, by forcing us to consider what sequence of molecular events in a cell could possibly allow for codon reassignment....Our ever-expanding list of nonstandard genetics is not serving to unravel the unity of biology. Instead they are strengthening our understanding of the mechanisms of evolution.
The unity of biology (i.e., common descent) is still intact, mainly because it was never really at risk.
Thus, it would be more accurate to say that Dawkins believes that all organisms share a common ancestor, despite the fact that they do not all have the same genetic code. In any case, he cant know that common descent is true because of the universality of the code. One cannot know something that isnt so.
I also found puzzling Dawkinss claim that the same hierarchy of cousinship appears with different molecules -- independent confirmations of the same tree. This brought to mind the old story about a railway stationmaster who announced that all the trains were running on time. When passengers complained that their trains were hours late, the stationmaster replied, Actually, what I meant to say was that the trains all run on time except when they dont.
In evolutionary systematics, the evidence all runs on time, except when it doesnt. Nearly any issue of Systematic Biology, Molecular Biology and Evolution, The Journal of Molecular Evolution, or Taxon (not to mention the many other journals in the field) will carry at least one report of a new molecular study contradicting a traditional morphological tree. As I was preparing these comments, for instance, I read the paleontologist Michael Novaceks critical response to new molecular trees in mammalian systematics that (he writes) suggest a radical shakeout of the placental tree, in ways not anticipated by morphological work (2001, R573).
Do these anomalous trains to revert to the railway metaphor count for, or against, the theory of common descent? I leave that question for the readers reflection. Again, however, Dawkins cannot know that common descent is true because molecules confirm morphology. It would be more accurate to say that Dawkins believes that all organisms share a common ancestor, despite the increasingly equivocal signals from systematic data.
In short, it would be more accurate to say that common descent is a rather special kind of theory.
Copyright 2001 Phillip E. Johnson, Paul Nelson. All rights
reserved. International copyright secured.
File Date: 8.13.01