This is Overview Section 6: “Biochemical Similarities,” and it is arguably the most obviously wrong section so far. That’s not good, because there are many other sections yet to go.
Ow! This has got to hurt. When you write something, and then you publish it in a book, and you try to push that book on science classes throughout the United States and even into some civilized parts of the world, and what you wrote is so obviously wrong, and everybody knows it and are making fun of you, where do you go from there? You go to the Discovery Institute Center for Science and Culture (CSC), that’s where you go. And that’s where Dean Kenyon (author) and Charles Thaxton (editor) of the creationist text Of Pandas and People now are twenty years after the original publication of the book. Both are listed as fellows of the CSC, and it’s something I guess they have to live with. Percival Davis is the other author besides Kenyon, and he is currently visiting professor of biology at Clearwater Christian College in Tampa, Florida.
In a previous section the authors discussed homology-similarity between diverse life forms. In that section the discussion related to morphological homology, similarity of form or body plan. In this section the discussion relates to chemical homology. On page 34:
Homology Writ Small
We all intuitively regard a horse as more similar in general structure to a cow than to a bird, but there is no way of measuring the difference between them in mathematical terms. Deciding which organisms should be classed together based on comparative anatomy and homology is always plagued by an element of subjective judgment. The revolution in molecular biology changes all that. It provides a new way to compare organisms based on the structure of their proteins and DNA.
One of the important procedures of biochemical taxonomy is the determination of amino acid sequences in protein, and the sequences of triplets in DNA. Researchers employ DNA and protein sequence analyzers to determine these sequences. Many proteins are used in a variety of organisms. It has been found that the sequence of a given protein, say cytochrome c, is not fixed but varies from species to species. Usually cytochrome c is composed of a string of one hundred and four amino acids. Though it performs the same function and is similar enough to be recognized as the same protein, it nevertheless differs among the various taxa. The amino acid sequences from two different organisms can be compared by aligning the two sequences and counting the number of individual amino acids that differ. Similar comparisons can be made between two strands of DNA. As an illustration, consider the two series of letters below:
These two series consist of ten letters each and differ in the three positions numbered. The measure of the difference is therefore 30 percent; if they diverged in two positions the difference would be 20 percent, and so on.
Animals with a greater number of similarities in DNA or amino acid sequence are classified more closely taxonomically. The classification system that emerges from molecular biology to a large extent confirms classifications traditionally made by taxonomists from anatomy. That is, a horse is more like a cow than it is like a bird not only in obvious appearance but also in the sequence of amino acids of its proteins, and of triplets in its DNA.
I reproduced the explanation from Pandas, because the book did seem to get that part right. Almost immediately the discussion goes completely off track. Immediately the statement, “Animals with a greater number of similarities in DNA or amino acid sequence are classified more closely taxonomically” is misleading. Animals are not classified closely taxonomically because of similar amino acid sequences. They are classified closely taxonomically because they share a recent common ancestor. Davis-Kenyon continue, heading off into the swamp.
Scientists are attempting to make additional evolutionary trees through biochemical comparisons, to check the older ones. But when measurements of the similarities between proteins are put side, the pattern that emerges contradicts the expectations based on Darwinism. Let’s look at this pattern in detail. Table 1 shows the percent of difference in amino acid sequence in cytochrome c between several organisms. (Note that even when the percentages are identical for more than one organism, the actual amino acid positions where they diverge are not likely to be the same.)
Davis-Kenyon are flatly wrong in the sentence I have highlighted above. Their own Table 1 puts the lie to their argument.
For your convenience I have reproduced here Davis-Keynon’s Table 1. I do not have another source for this information, so what follows is based on the assumption the authors have gotten this right. Here’s how it works: For example, humans are number 1. Look at column number 1. It shows to nobody’s surprise that human cytochrome c differs from human cytochrome c by a zero amount. Now get serious. Davis-Kenyon are going to talk about the silkworm moth (item 15), which is an insect. Please notice that the first 14 items, humans through lamprey, are vertebrates. Recall from your high school biology that insects (arthropods) and vertebrates diverged from each other at the same time millions of years ago. Now look at column 15 (moth). The first 14 differences are 28, 28, 25, 27, 24, 26, 26, 25, 26, 27, 30, 25, 30, 30. All the vertebrates differ from the insect by roughly the same amount. I emphasize the word “roughly.” This is biology, not rocket engineering. We are looking at a molecule that has changed from time to time in the last 500 million years, and God was not keeping score. Now see what Davis-Kenyon have to say:
Now look at the entry for silkworm moth (No. 15 at the top of the table) and this time go down the table from vertebrate class to vertebrate class. Notice that the cytochrome c of this insect exhibits the same degree of difference from organisms as diverse as human, penguin, snapping turtle, tuna, and lamprey. Considering the enormous variation represented by these organisms, it is astonishing that they all differ from the silkworm moth by almost exactly the same percent.
Well, that’s refreshing. I have not witnessed such naiveté on the part of educated scientists in quite some time. Actually, not since I last reviewed a creationist’s book advocating Intelligent Design. One of several possibilities has occurred: The authors have started to believe their own stuff and now think that the form of the cytochrome c molecule should closely track the form of the organism. That would be so puzzling, first because there is no reason the chemical makeup of the molecule should take a cue from body plan and vice versa. Second, the whole idea of tracking molecular differences is to trace the history of the evolution of the various species. For the past 500 million years the cytochrome c molecule has been passed down from generation to generation, and now I have my own copy. Only, along the way, due to accidental mutations in the DNA sequence that produces the cytochrome c protein, there have been changes to the molecule between consecutive generations, and the new molecule has been passed down to subsequent generations after each change. Arthropods and vertebrates went their separate ways over 500 million years ago, and the changes in arthropod cytochrome c and vertebrate cytochrome c have not tracked each other ever since. They have gone their separate ways, and differences have accumulated all this time-around 25 to 30% according to table 1.
The other possibility to consider is that Davis and Kenyon are deliberately lying to their readers, who are supposed to be high school students trying to make the decision whether to believe in the true God of Abraham or the false god of natural science. I am thinking that lying to students is not the way to win hearts and minds. I mentioned Glen Morton in a previous post. He believes in God and creation, but he is also a real scientist, a geologist. At a creationist meeting in Dallas he cautioned creationists in attendance against teaching their children the false notions of so-called flood geology and a young (less than 10,000 years) Earth. He warned that when they later learned the truth they would lose faith in what they had been taught at home and at church.
I am inclined to go with the second of these two conclusions, and here is my reasoning:
Davis has an M.A. degree in zoology from Columbia University-no slouch of an academic institution. He also holds a Ph.D. in instructional design from the University of South Florida-by no means a diploma mill. Dean Kenyon received a B.Sc. degree in physics from the University of Chicago and a Ph.D. in biophysics from Stanford. The editor of Pandas is Charles Thaxton, who has a Ph.D. in physical chemistry from Iowa State University. What I am getting at is that none of these people have any excuse for making a mistake like what they have written in this book. The only reasonable possibility is they set out in the morning to perpetrate a hoax on their readers.
I appreciate a liar more than I do a fool. Somebody once complained about my position on this, but my standard response is, “At least a liar will listen to reason.”
Whether or not the authors know what they are doing, they proceed to dig themselves deeper. On page 38 they provide additional “evidence.” Here I have reproduced their Figure 9, except without the nice artwork, including silhouettes of the various animals.
Figure 9. The sequence differences (percent divergence) between the cytochrome c molecules of the carp and several other vertebrates. Notice how close these percentages are to each other.
Please notice for yourself. All other vertebrates diverged from fish at the time of the emergence of amphibians (the frog), and all show about the same molecular differences from the carp (a fish). Quickly, before your lose consciousness from all this BS, please go back to Table 1 and see for yourself.
The carp is a fish, and it differs from other fish, lamprey, dogfish and tuna by 12, 14 and 8. Evaluate these differences in light of the fact that the carp is a boney fish with a jaw, like the tuna, and the dogfish is a kind of shark, a fish with cartilage instead of bone. Fish with jaws diverged from jawless fish a long time ago, and the carp is a jawed fish while the lamprey is a jawless fish. Assume the table is correct and see for yourself whether it correlates well with the hierarchy of life forms on this planet as explained by the modern theory of evolution.
What I find so amusing is that this argument involving molecular homology is the same one that young-Earth creationist Duane Gish used to make in his debates with scientists decades ago. Gish’s nonsense has been picked apart in public rebuttals all this time, and one debater used the term “bullfrog” instead of a similar word when the topic came up. I even published a review in the July 1998 issue of The North Texas Skeptic. There is more in the October 2001 issue.
The authors say a lot more along the same line as the arguments I have quoted, but I will not belabor the point. That would require me to post just about the entire chapter on-line. Please contact me if you need additional quotes but don’t have access to a copy of the book.
This is the last of the Overview sections in the book. The remainder of Pandas involves what the authors call their Excursion chapters, beginning with Chapter 1, “The Origin of Life.” They are going to take the same topics they covered in the first part of the book and elaborate on the discussion in greater detail. Stand by for more of the same. And may God have mercy on your soul.