Monday, January 11, 2010

Ayala Review of Signature in the Cell

Francisco Ayala, one of the world's preeminent evolutionary biologists and a former Dominican Priest has a review of Stephen Meyer's new book Signature in the Cell. The opening paragraph is a howl:
The keystone argument of Signature of the Cell is that chance, by itself, cannot account for the genetic information found in the genomes of organisms. I agree. And so does every evolutionary scientist, I presume. Why, then, spend chapter after chapter and hundreds of pages of elegant prose to argue the point? It is as if in a book about New York, the author would tell us that New York is not in Europe, and then dedicate most of the book to advancing evidence that, indeed, truly, New York is not in Europe.
This is, indeed a continual problem for the ID movement: the lack of understanding of how evolution operates. There is a disconnect between the understanding of how mutations arise and what selection does with them. It is as if supporters of ID complain about "Darwinists" but none of them have actually read any Darwin. In every generation there are a wide variety of mutations that arise in the genome. Selection acts accordingly. There is directional selection, balancing selection and disruptive selection. The best known example in humans of balancing selection is the balanced polymorphism where the sickle cell trait is maintained in a population because heterozygotes that carry one copy of the gene can fight off malaria and still not die from sickle cell anemia. Our current genome and that of all other animals is the result of generations of selection. It isn't chance at all. Ayala's complaints about the book run deeper, however:
Meyer asserts that the theory of intelligent design has religious implications. “Those who believe in a transcendent God may, therefore, find support for their belief from the biological evidence that supports the theory of intelligent design” (p. 444). I do think that people of faith may find in the world many reasons that support their belief in God. But I don’t think that intelligent design is one of them. Quite the contrary. Indeed, there are good reasons to reject ID on religious grounds, in addition to scientific grounds. The biological information encased in the genome determines the traits that the developing organism will have, in humans as well as in other organisms. But humans are chock-full of design defects. We have a jaw that is not sufficiently large to accommodate all of our teeth, so that wisdom teeth have to be removed and other teeth straightened by an orthodontist. Our backbone is less than well designed for our bipedal gait, resulting in back pain and other problems in late life. The birth canal is too narrow for the head of the newborn to pass easily through it, so that millions of innocent babies—and their mothers—have died in childbirth throughout human history.
To be fair, most of the arguments here fall under the heading of "personal incredulity." Maybe God did design these things the way are on purpose. The point is that there is no way to know whether God did it or that it just happened without the help of a designer. All we know is that we have a theory (biological evolution) that, as Mr. Spock would say "just happens to fit the facts."

Here is an odd problem, though: your average evangelical Christian views the modern workings of the world and all of its myriad problems as being the result of the curse of Adam and the resultant fall. All bad things that happen to people biologically, be it cancer, miscarriage, MS, Alzheimer's Disease to name a few, can be tied to this. It is clear from reading Ayala's other work that is not how he thinks. His is more of an "evolving creation" that operates under God given natural laws. Most practicing biologists that work with evolutionary theory have adopted some variant of this. What isn't clear is how Meyer thinks regarding this. Is there intelligent design despite the fall? Can we see the work of the designer through the muck of modern life? No ID author that I am familiar with has addressed this issue.

It is clear, however, that, based on my example of the sickle cell trait, evolution does act on the modern world. Further compounding the issue is the study of things like ERVs that indicate that, despite their virulent nature, they present a perfect example of exaptation, and that section of our functional genome came from old ERV infections.

What does all of this mean? Is God working through his fallen creation to "help us out?" Are the examples of natural selection God's plan to navigate us through the evil of the modern world? I would like to see an ID supporter like Michael Behe, Stephen Meyer, or William Dembski address this issue because the current ID argument that evolution cannot explain the modern genome leads one to wonder how it was created and, if the world is evil, why.

Hat tip to Steve Matheson.

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  1. Hi! Nice to find your blog. Re: problem of evil, some of them have addressed it, kind of. Dembski has a book/article out that argues that the earth is old but evil, e.g. animal death 500 million years ago, was retroactively caused by a literal fall of man say 10,000 or 100,000 years ago: "Christian Theodicy in Light of Genesis and Modern Science".

    Behe, "Edge of Evolution":

    "Malaria was intentionally designed. The molecular machinery with which the parasite invades red blood cells is an exquisitely purposeful arrangement of parts. (...) What sort of designer is that? What sort of "fine-tuning" leads to untold human misery? To countless mothers mourning countless children? Did a hateful, malign being make intelligent life in order to torture it? One who relishes cries of pain? Maybe. Maybe not." (p.237)

  2. "A theory that fits the facts"?

    Not good enough! A theories my seem to be the "best fit" if it is consistent with the evidence.
    Evidence plus consensus of observers does not produce an absolute fact. Evidence may show a constant probablity but not necessarily show absolute actuality.
    Many innocent people have been put to death because of this faulty reasoning.
    ...James E Gambrell