Signature in the Cell


Spectrum Magazine | by Ken Peterson | Sep. 23, 2009

This year marks the 150th anniversary of the publication of On the Origin of Species by Charles Darwin. The book set off what has been at times a ferocious argument concerning the validity and scope of his theories. A new book by Stephen C. Meyer, Signature in the Cell: DNA and the Evidence for Intelligent Design, is not about the transmutation of species over time. Rather, it is about a much older controversy that has extended for thousands of years concerning the origin of life, something that Darwin did not really address in his book. This old controversy has often been between two essential poles: materialistic naturalism (time plus random, undirected chance) or God.

For example, we can see elements of this controversy played out in the Bible over the centuries of its development. For the sake of brevity I will only note Genesis 1:1 (“In the beginning God created the heavens and the earth.”) and Psalms 14:1 (“The fool hath said in his heart, there is no God.”) In the 150 years since 1859 the dominant scientific establishment has, it is fair to say, fully embraced the “materialistic naturalism” model generally and specifically as applied to origins.

Signature in the Cell proposes to revisit the origins controversy particularly in light of the discovery over 50 years ago of DNA and the enormous advances in our knowledge of cellular biology and information theory since then. Meyer does this using the motif of his personal journey toward understanding what he calls “the DNA enigma.” This enigma is “the mystery of the origin of the information needed to build the first living organism.” Until such a first life exists Darwinian evolution cannot commence.

Thus, Meyer’s book, if he can successfully carry the burden of proof, is probably one of the most important books since Copernicus challenged the prevailing scientific notion 566 years ago that the Earth was the center of the universe. Here, Meyer methodically challenges the central doctrine of today’s scientific establishment that life arose from purely undirected materialistic and naturalistic forces in the absence of intelligence.

The book itself is a little over 600 pages in length, although the last 100 is made up of footnotes, bibliography and index. Meyer, currently the director of the Center for Science and Culture at the Discovery Institute in Seattle, tells his story of going to Cambridge University in the mid-1980s as he earns his Ph. D. in the history and philosophy of science. He investigates various relevant questions and narrates his odyssey to marshal the evidence necessary to provide answers. His writing is lucid and straight-forward. To a non-scientist the material is not always easy given the details he presents, so it is not really bedtime reading. I especially appreciated, however, that he handled those who disagree with him respectfully and openly. The story is engaging and the fascinating history he shares is helpful to provide a context for today’s controversy.

While the book chronicles and explains a host of issues, I was fascinated by the discussion of random chance and the assembly of the minimum amount of proteins necessary for “simple” life to function. According to Meyer the “simplest extant cell, Mycoplasma genitalium — a tiny bacterium that inhabits the human urinary tract — requires ‘only’ 482 proteins to perform its necessary functions….” If, for the sake of argument, we assume the existence of the 20 biologically occurring amino acids, which form the building blocks for proteins, the amino acids have to congregate in a definite specified sequence in order to make something that “works.” First of all they have to form a “peptide” bond and this seems to only happen about half the time in experiments. Thus, the probability of building a chain of 150 amino acids containing only peptide links is about one chance in 10 to the 45th power.

In addition, another requirement for living things is that the amino acids must be the “left-handed” version. But in “abiotic amino-acid production” the right- and left-handed versions are equally created. Thus, to have only left-handed, only peptide bonds between amino acids in a chain of 150 would be about one chance in 10 to the 90th. Moreover, in order to create a functioning protein the “amino acids, like letters in a meaningful sentence, must link up in functionally specified sequential arrangements.” It turns out that the probability for this is about one in 10 to the 74th. Thus, the probability of one functional protein of 150 amino acids forming by random chance is 10 to the 164th. If we assume some minimally complex cell requires 250 different proteins then the probability of this arrangement happening purely by chance is one in 10 to the 164th multiplied by itself 250 times or one in 10 to the 41,000th power.

That sounded like a pretty big number to me, making it a very small possibility, but is there a way to judge how small? Is there some point at which we can say that such a number is essentially “impossible”? It turns out there may be. Meyer points out there are about 10 to the 80th elementary particles in our observable universe. Assuming a Big Bang about 13 billion years ago, there have been about 10 to the 16th seconds of time. Finally, if we take the time required for light to travel one Plank length we will have found “the shortest time in which any physical effect can occur.” This turns out to be 10 to the minus 43rd seconds. Or turning it around we can say that the most interactions possible in a second is 10 to the 43rd. Thus, the “probabilistic resources” of the universe would be to multiply the total number of seconds by the total number of interactions per second by the total number of particles theoretically interacting. The math turns out to be 10 to the 139th.

If Meyer stopped here and simply asserted that “since undirected, random chance cannot produce even one protein (given the entire resources of the universe) then life must be attributable to an Intelligent Designer,” he would be guilty of something that he strenuously denies: relying on a “God of the gaps” argument. Meyer does not do this. Instead, he explains “abductive reasoning” which enables one to come up with the “best explanation” of a particular unique historical event. He calls this a “historical scientific theory.” In fact, Meyer says that Darwin and his contemporary, Charles Lyell, the father of geology, used such reasoning themselves to explain their theories. In short, “God of the gaps” argues from ignorance whereas “Inference to the Best Explanation” argues from knowledge. Of course, knowledge is continually expanding so any conclusion must be continuously re-evaluated in light of such advances.

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