Synopsis Of Chapter Eleven, Signature In The Cell, by Stephen Meyer
ISBN: 9780061894206; ISBN10: 0061894206; Imprint: HarperOne
Biological determinists will argue on the assumption that universal laws undergird the origin of life. Such an appeal to natural law is of course not a novel one. Indeed even thousands of years ago Aristotle philosophized over the existence of some universal organizing principle that could shape life into the easily identifiable forms we see today. From a protein sequence perspective Pennsylvania State University biochemists Gary Steinman and Marian Cole gave seemingly empirical substance to the idea that there were certain combinations of amino acids that were more likely to form as a direct result of amino-acid bonding energies.
Along the same grain, biophysicist Dean Kenyon became a die-hard advocate of the view that proteins first assembled into functional entities through the selective affinities that specific amino acids had for one another. To be sure, Kenyon believed that specific protein sequences were somehow predestined to form as a direct result of such constraints. The title of his much-respected tome Biochemical Predestination, which he co-authored with Steinman, became a spark that served to boost his credibility. But as his joint book garnered strength as a staple text for biochemistry graduate studies in the 1970s, Kenyon himself began to have personal doubts over the validity of his own proposition. Interviewed as part of the Discovery Institute’s documentary Unlocking the Mystery Of Life, Kenyon’s own testimonial brought clarity to the depth of his ongoing struggles:
“There was this enormous problem of how you could get together into one tiny sub-microscopic volume of the primitive ocean all of the hundreds of different molecular components you would need in order for a cell replicative cycle to be established. And so my doubts into whether amino acids could order themselves into meaningful biological sequences on their own without pre-existing genetic material being present just reached an intellectual breaking point. The more I conducted my own studies including a period of time at the NASA Ames Research Center the more it became apparent that there were multiple difficulties with the chemical evolution account”.
I first learned of Kenyon’s misgivings in the Foreword he wrote for another ground-shifting manifesto The Mystery Of Life’s Origins where he noted how it was the information-bearing attributes of both polynucleotide and polypeptide sequences that he had found most vexing and unexplainable. For Stephen Meyer, his own philosophical pilgrimage brought him to the writings of Michael Polanyi who at the end of the 1960s argued that the language-style content of DNA could not be reduced to the mere operation of natural and physical laws. Just as the ink on a paper could not explain the message communicated on a printed page, so the information conveyed in a DNA molecule transcended the chemical and physical properties of its smaller component subunits.
The structures of DNA and RNA presented no escape chute for the chemical evolutionist. As with proteins, there were no constraining forces or ‘differential affinities’, this time along the phosphate backbones of DNA and RNA, that would make any given base sequence more likely than any other. Meyer transpicuously relays this point to the reader by comparing the base letters of DNA and RNA to magnetic letters on the metallic surface of a refrigerator (For further discussion see We Have No Excuse: A Scientific Case for Relating Life to Mind by Robert Deyes and John Calvert). In the same way that the placing of such letters into meaningful strings cannot be reduced to the magnetic forces between them and the refrigerator, so the information-carrying aspects we observe in DNA and RNA bases cannot be attributed to physical and/or chemical constraints.
Constructing his case on the shoulders of prominent philosophers and scientists, Meyer shows how the absence of biological determinacy is a fundamental feature of both codon/amino-acid assignments and the correspondence between amino acids and their respective tRNA molecules. The need for sequence “freedom” in DNA is imperative if it is to be a molecule of “virtually unlimited novelty” that can store information. To draw yet again from one of Meyer’s outstanding depictions, there is no more inevitability in the assembly of functional genes from the ground up than there is in the construction of the palace of Versailles from bricks and mortar.