Plagiarized Errors and Molecular Genetics
A Response to David Plaisted
Copyright © 1997 by Edward E. Max, M.D., Ph.D.
[Last Update: April 5, 1997]
Dear David Plaisted,
I have read your web page posting called "Shared Errors in the DNA of Humans and Apes," which is apparently a response to my essay ("Plagiarized Errors and Molecular Genetics") on Talk.Origins, although you do not mention the essay by name or URL. I thought you might be interested in my response to your response.
You state that "at first glance" you found my essay a strong argument for evolution, implying that after a while it seemed less of a problem for you as a creationist. If the numbered points in your posting reflect the reasons for your shift in attitude, my guess is that this shift occurred because you gradually forgot the details of my essay; all of your numbered points seem to me to have been already answered in the essay.
The first part of your point #2--i.e., that it is too soon to draw conclusions about the implications of pseudogenes and retroposons ("we are still learning")--is answered by section 5.2 of the essay. Hundreds of papers on pseudogenes and retroposons have been published in the last 15 years, with the findings replicated in many laboratories, so that at present "we know enough about how they arise that we do not need to postulate any mysterious designer or unknown function to explain them." We would scarcely be swayed by an accused criminal whose only defense was that "he should be found innocent because some time in the future evidence might be discovered that could exonerate him." As scientists we provisionally accept what the current evidence tells us, always recognizing that future data may require us to revise our view. Based on this current evidence, shared pseudogenes and retroposons represent ancestral genetic accidents arguing for an evolutionary model, and there is no reason--other than religious faith--to expect anything different in the future. As to your suggestion that we should see whether the similarities in the DNA of different species can be placed in a consistent evolutionary tree, this kind of data has been extensively examined and does yield a consistent evolutionary tree, within statistical error (as I indicated my section 1.1).
Your idea (point #4) that "the Lord inserted those similarities for a reason we do not understand. . .[perhaps] as tests of our faith" is answered by section 5.10 of my essay. The Lord might just as well have created--as a test of our faith--ANY scientific evidence that strongly supports evolution, including radiometric characteristics of minerals and Australopithecus fossils. Your attitude seems to be like the typical creationist approach: if a "scientific" argument seems to support creation, then they claim that scientific evidence is a valid way to bolster the truth of creation; but if the evidence supports evolution, then they call it a "test of our faith" and deny it as a valid support for evolution. This attitude seems to be shared by many creationists. Indeed in the April, 1997 Acts & Facts distributed by the Institute for Creation Research, Henry Morris, the founder of that organization, writes: " . .we believe the Bible must take priority over scientific theories." The creationist notion that you can pick and choose scientific findings that you like and discard those that don't fit your preconceived dogma--calling them Divinely created artefacts beyond our understanding, or a "test of faith"--is an anathema to real scientists like myself, and is a major reason for the vigor with which we oppose allowing the pseudoscience of creationism in science classrooms. On a personal note, I would like to make clear my own respect for those who accept a literal view of creation, placing Bible over science as a matter of religious faith. A mathematical proof compels acceptance of a theorem; but there is nothing in my essay (or elsewhere in the scientific realm) that compels a belief in evolution for someone who has chosen to believe in creation because of the religious authority of the Bible. No one should be forced to value the scientific method over religious faith. However, I believe that those who hold a view of creation based on religious faith should not try to pretend that their belief is based on unbiased scientific judgment, and should certainly not try to propel their views into the public school science classroom under the false cloak of "scientific" creationism. A creationist response to my essay that I could respect would be: "The essay seems to show strong scientific support for evolution, but my religious faith persuades me that the conclusion is wrong even though I don't see any scientific flaw in it."
Your point #3 (mutations are not completely random, so some shared mutations may have occurred independently) is a theoretical possibility, but where is the evidence that would support it if it were true? In fact, scientists cataloging the gene mutations that cause specific genetic diseases have found scores of different mutations can inactivate particular genes; so you might have a difficult time making your case that any particular shared mutations were due to independent non-random events. Your argument also overlooks my section 5.9, in which I point out that for the case of retroposon insertion, identical independent insertions have not been observed even in individuals of the same species.
Your point #5 is an ad hoc religious hypothesis, based on what seems to me rather shaky theology (God punishes monkeys for human sins?). But more importantly it neglects the fact that the most compelling, as well as the most numerous, examples that support my thesis are cases where the "errors" could hardly be considered a "curse" because they do not affect the organism's well-being in any detectable way.
As to my use of the word "error" (your point #6), I remind you that I carefully defined a rather specialized meaning of this word for the purpose of this essay (my section 2.2). You may argue as a point of rhetoric that I should have coined an entirely new term to express the concept that I defined, but I believe that this would have been more confusing to readers.
Your point #7, suggesting that a pseudogene could have evolved from meaningless DNA to resemble a functional gene by successive random mutations is preposterous, and that is why I dismissed this possibility in my section 4.7. Indeed Dr. Gish provides many calculations that demonstrate how impossibly unlikely such an event would be. His calculations are completely inappropriate to explain the probability of evolving a FUNCTIONAL gene because he ignores the evolutionary mechanism of multiple iterations of selection for tiny improvements of function. But his calculations are precisely appropriate for demonstrating that it would be impossible for random mutations to produce a pseudogene IN THE ABSENCE OF SELECTION FOR FUNCTION, which is what you propose.
Your point #8 suggests that humans and chimps may share pseudogenes for vitamin C metabolism through independent mutations resulting from loss of selective pressure to preserve functional genes, or even through selective pressure to inactivate the genes (your point #9). I fully agree that this is possible; indeed the history of galactosyltransferase genes appears to follow a very similar scheme (as I pointed out in the box to section 4.1). But as I mentioned above, when scientists examine the mutations in a particular human gene to understand the cause of a genetic disease, they generally find that many different mutations that can inactivate a gene. Therefore, as I mentioned in section 4.1, if primates closely related to humans have the SAME crippling mutations in their LGGLO pseudogenes as we see in the human pseudogenes, this finding would support the evolutionary model. As I pointed out, the data on this question are not yet available for the LGGLO pseudogenes, but in other shared pseudogenes identical crippling mutations clearly favor evolution (see my section 4.2).
Your point #10--that we should not speculate on the relationships between living organisms because these relationships reflect Divine ideas--seems to be a purely theologic argument, which I cannot comment on from a scientific perspective except to say that it sounds rather anti-science to me. (Are the relationships of living forms any more the product of the mind of God than are the laws of physics? Isn't most of theology and religion an attempt to understand what might be called the mind of God?)
I could not understand your next to last paragraph at all. Perhaps you should reformulate it.
I am sorry if my essay was marred by any appearance of sarcasm (certainly unintended), but I cannot accept your criticism that it was "biased" unless you can show me an example of a conclusion that I drew from the evidence incorrectly because a preconceived notion inappropriately swayed my interpretation. I do have a strong opinion based on my conclusions from the evidence I described, and I tried to express that opinion clearly. I consider this the appropriate function of a scientist; it's what I try to do every day in my work. A well-founded opinion is not the same as a bias. In contrast, the practice of accepting scientific evidence only when it seems to confirm your dogma, while denying dogma-challenging observations (calling them too "new" to be accepted, or a "test of faith" rather than a reflection of material reality) does reflect bias in my view. When creationists invoke the unfathomable workings of God as an alternative explanation for any evidence that contradicts their position, they may satisfy themselves that they can cling to their beliefs without facing a stark challenge to their faith; but when they do so, I believe they relinquish the right to be taken seriously as participants in unbiased scientific discourse.
P.S. A reader of your essay--the one who pointed it out to me--suggested that I post my response for readers of Talk.Origins. I am doing this by sending a copy to the Webmaster for that site.
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