Friday, July 27, 2007

The Edge of Evolution - Michael Behe

Where can we draw the line between the capabilities of random chance and the evidence of intentional and intelligent design? In other words, how far up the complexity scale can random chance really travel and how far down the complexity scale is there evidence of design? Where can we draw the line?

This is the question that Michael Behe both asks and answers in this new and compelling book. Like many in the Intelligent Design movement, he discards the notion that evolution and Darwinism are synonymous and instead examines three smaller concepts, random mutation, natural selection, and common descent, on their own individual merits. The novelty about his approach to the subject is his clarity in explanation and his astronomical empirical data sample upon which he bases his conclusions. His case is overwhelming.

More specifically, he uses the genetic data available on malaria, HIV, and E. coli (as well as the human genetic response to these micro-organisms) over roughly the past fifty years as his data sample. For malaria alone this is a sample size of approximately one hundred billion billion organisms. How much has random mutation accomplished in one hundred billion billion chances? Not much. Nothing new, nothing constructive, no new cellular machinery, no new genes or genetic material, nothing but a few “broken” genes which both damage the malarial organism and yet also make it immune or resistant to the drugs we use to kill it.

So does Darwinism work? Yes. Darwinism is the perfect explanation for the resistance that malaria gained against chloroquine (and other drugs). A random mutation provided resistance to the drug, therefore this new genetic trait caused the mutant parasite to out-compete its rivals and this mutation became a widespread trait in the population. Random mutation, natural selection, common descent all work. The question, however, is not whether Darwinism works. The question is how much random mutation can realistically accomplish. The answer, to repeat myself, is “not much”. So while random mutation (and hence Darwinism when paired with natural selection and common descent), can accomplish some relatively modest changes given a large enough population size, it is severely limited.

For reasons that I will defer to Behe to explain, random mutation can only realistically accomplish a maximum of two simultaneous and specific protein-protein interactions (that is among existing proteins), or single-point mutations. This is exactly what happened in malaria out of one hundred billion billion chances. (The details are important here and I am leaving out a lot, but I can’t give all that to you in this space. Read the book). To recap, if we draw our line where Behe does at the two-binding-sites rule, we are left with the following realization: random mutation could not have accomplished any significant evolution. Not only is this true for single-celled organisms which reproduce quite rapidly, but imagine the problem for higher animals: one hundred billion billion is more mammals than have ever existed and yet the differences between them are much much greater than two protein binding sites. Random mutation can simply not account for such changes. Especially not when you consider that those changes would involve the creation of entirely new and complex genetic material.

Here, then, is the “edge of evolution”. Random mutation can statistically generate small changes given a large enough population but if fails to create anything greater than a two-binding-site difference (see the book for an explanation). Therefore, Darwinism is a good explanation for certain biological phenomena such as antibiotic resistance in micro-organisms and certain genetic diseases like “sickle-cell”. In all of these cases, the operative change is small and although beneficial in an immediate and desperate sense actually decreases the function of the organism in question. The trait is only selected because it provides resistance to a disease or drug. Anything beyond this should be properly understood as the product of intelligent design.

Keep in mind, again, that I have left out a large amount of information in my explanations. My summaries are rough at best.


At 9:11 AM, Blogger X-Evolutionist said...

Michael Behe is one of my heros. I haven't read The Edge of Evolution, yet. But I have read his book Darwin's Black Box, and recommend it wholeheartedly.



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