micro rna.jpg
micro RNA (let7; pink) bound to mRNA (lin-41; cyan). miRNAs are small non-coding RNA molecules important for gene regulation and implicated in cancer, obesity and heart disease.
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Stephen C. Meyer Philosopher of Science
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Can the Origin of the Genetic Code Be Explained by Direct RNA Templating?

Published in Bio-Complexity, Vol 2011

Origin-of-life research has a big problem, and the DRT model purports to solve part of it. Critics of intelligent design have advanced the DRT model as the answer to the sequencing problem — how genetic information in RNA (in the hypothetical RNA world) eventually could have been translated into more stable and versatile proteins. In a peer-reviewed paper published in BIO-Complexity, Stephen C. Meyer and Paul Nelson take on DRT.  In their critical review of the research they explain how the sequencing problem has not been solved, even partially. Read the paper here.

Abstract: Motivated by the RNA world hypothesis, Michael Yarus and colleagues have proposed a model for the origin of the ‘universal’ genetic code, in which RNA aptamers directly template amino acids for protein assembly. Yarus et al. claim that this “direct RNA templating” (DRT) model provides a stereochemical basis for the origin of the code, as shown by the higher-than-expected frequency of cognate coding triplets in aptamer amino acid-binding sites. However, the DRT model suffers from several defects. These include the selective use of data, incorrect null models, a weak signal even from positive results, an implausible geometry for the primordial RNA template (in relation to the universally-conserved structures of modern ribosomes), and unsupported assumptions about the pre-biotic availability of amino acids. Although Yarus et al. claim that the DRT model undermines an intelligent design explanation for the origin of the genetic code, the model’s many shortcomings in fact illustrate the insufficiency of undirected chemistry to construct the semantic system represented by the code we see today.