Monday, June 19, 2006

Evolution: my dialogue with a scientist

A month ago I exchanged email with Douglas L. Theobald, a Postdoctoral Fellow in the Department of Chemistry and Biochemistry University of Colorado at Boulder and the author of 29 proofs of macroevolution . He was kind enough to answer two questions which I have concerning evolution. I greatly appreciate his patience.

My first question concerned the probability of evolution occurring:

It seems to me that the concept of evolution might be compared to the concept of an illiterate author.
Let's say that someone wanted to publish books and become a great author. But he was totally illiterate. He could not read or write one word; letters looked to him like meaningless scratches on the page.
So he came up with a solution. He would buy a printing press, open a bookstore, start printing and make more copies of whatever sold. At first he just arranged his printing type at random, printed and put the results on the shelves. No one bought anything since it was all gibberish. He threw all these failures into the recycling bin and continued printing. Eventually, purely by chance, one small booklet actually made sense and in fact became a best seller. So he kept printing more copies of it. Occasionally, there would be some typographical error in the printing, purely by chance. A page would be smudged, a line would be missing. Generally these errors would cause the book to be unpurchased and it would be thrown into recycling. However once in a while a typo would add more meaning to a copy of the book - a few interesting new sentences. People would ask for more copies of it. That typo would be then be faithfully reproduced by the illiterate author. Gradually entire new books developed through this process of random typographical errors and customer selection. Eventually, the inventory in the book shop had expanded to include tens of millions of titles including novels, plays, poetry, scientific textbooks, history, biography, huge dictionaries and encyclopedias and so on. In fact, these books were actually far more beautiful and profound than books ever written by any human author. All produced by a totally illiterate author through a process of random printing, typos and customer selection over a very long period of time.

Needless to say most people, including most mathematicians, would be very skeptical about this story of an illiterate author. Even given billions of years and billions of illiterate authors making the attempt it seems to be ridiculously unlikely that it could ever happen. However this is exactly what evolutionists consider to be the origin of life - nature is a mindless engineer, combining molecules at random until some became self reproducing. Then random mutations and natural selection combine together to create all the diversity and complexity we see in life around us.

Dr. Theobald answered me as follows:

Your analogy is, for the most part, sound. However, there are several points to be made. First, just because you think something is astounding has very little relevance to its scientific validity. There are all kinds of things in science that amaze me: particles behave as waves and tunnel through walls, Euclidean geometry does not work in the real world, stars are billions of miles away, invisible radiowaves are carrying messages all around me (and through me) right now, etc. Our amazement is irrelevant; the real question is whether the amazing thing is true or not. Second, your insinuation that "most mathematicians [are] skeptical" of random mutation and natural selection is false. As it turns out, the mathematics of genetics is extremely rigorous and a large field in its own right (and has been for 100 years), and there is no contradiction between what the math says and what biological genomes show. For example, see morphological rates and genetic rates.


As far as the Internet references which Dr. Theobald provides, as I understand them, the first demonstrates that if we measure the rate of change which is observed to occur within species, as a result of selective breeding or environmental pressures, and extrapolate this same rate of change over geological time, we should in fact see evolution progressing far more rapidly than the geological record indicates. In other words, if a breeder can breed a Great Dane from a coyote in 200 years, he should be able to breed an elephant from a coyote in 5,000 years. I think most animal breeders would be highly skeptical of such an assertion.

The second reference indicates that genetic mutations occur sufficiently frequently to account for the transformation of an ape into a human in approximately 6 million years. This seems to assume that all mutations add reproductive value to their recipient (or, in my analogy, they are good typos which add to the marketability of the book), while in reality few if any do. Click here for more detail.

As I understand it, Dr. Theobald is conceding that the evolution is difficult to believe, however, like many other amazing events, it may nevertheless actually have taken place. It should be obvious however that extraordinary claims require extraordinary evidence. If I claim that I ate breakfast this morning with my wife, little evidence would be required to convince someone. If I claim that I ate breakfast this morning with President Bush, stronger evidence would be needed.

Since evolution allegedly occurred during eons of prehistoric time, the only possible direct evidence of evolution would be the fossil remains of animals in the process of evolving. Therefore I asked Dr. Theobald about the strength of this evidence:

Animals which have only soft body parts, of course, may not be preserved as fossils. Also, terrestrial animals may seldom be fossilized because when they die their bodies lie exposed and are usually quickly destroyed. However marine animals which have bones or shells are often fossilized as they die and their bodies fall to the ocean floor and are covered by sediment. This sediment turns to stone and creates fossils. According to Darwin, we should therefore today have a beautiful record of the gradual transition, in millions of tiny steps, from the earliest vertebrates over 510 million years ago up to modern fish about 200 million years ago. There should be a detailed record in the fossils of every branch of fish evolution. In fact, that is not the case. New species appear suddenly in the fossil record. And to claim that indeed fish evolution did take place, however new species always originated in small, isolated bodies of water whose fossils have been lost is a poor excuse. Darwin wrote in "Origin of Species" chapter 10 at the end: "Those who believe that the geological record is in any degree perfect, will undoubtedly at once reject the theory [of evolution]." Not very much has changed since then.


Dr. Theobald answered me as follows:

Actually, much has changed since then, as we have found many many more fossils, esp. transitional forms that were predicted by evolutionary theory. Darwin was correct in his statement above -- but it is the highest absurdity, given what we know about geology and fossilization, to think that "geological record is in any degree perfect".


As I understand him, Dr. Theobald is agreeing that some, however not very strong, direct evidence of evolution exists.

For more details about the problem of transitional fossils, click here.


I would suggest that each reader review the above dialogue carefully and draw his own conclusions.

2 comments:

J.I. said...

Improbable things, even extremely improbable things, happen all the time. According to the laws of probability, the most improbable things also have to occur sometimes.

Also, it depends from what end you look at things. If you looked at the probability of human life evolving before it evolved, then you would say that it is extremely improbable. But if you look at it from the present, then you know that it did happen, so to argue that it is improbable and therefore couldn't have happened doesn't work.

In addition, how can we know whether the laws of probability existed in the very distant past? If probability is some kind of mathematical Truth - do Truths always exist or do they also come into being at some point?

jewish philosopher said...

“it is improbable and therefore couldn't have happened doesn't work”
It could not have happened by chance. Someone did it deliberately.