Evolution in Many-Sheeted Space-Time: Genetic Code

Abstract

In this article a physical model for the genetic code (not the only one) and its evolution are introduced and McFadden's views are compared with TGD views. A model for the evolution of the recent genetic code (3-codons) as a fusion of codes for which codons are nucleotides (1-codons) and di-nucleotides (2-codons) is discussed.  The symmetries of the genetic code, the observation that tRNA can be seen as a fusion of two hairpin like DNA molecules, and the finding that the first nucleotides of 3-codon code for the reaction path leading from a precursors of the amino acid to amino acids for hydrophobic/hydrohilic dichotomy, serve as motivations of the model. 1- and 2-codes corresponding to the two forms of RNA (the exotic 2’-5’ RNA and the usual 3’-5’ RNA) would have prevailed in RNA world.  Amino acids would have served as catalysts for the copying of RNA on one hand, and RNA molecules would have catalyzed the formation of amino acids from their precursors on one hand, meaning the presence of a positive feedback loop. In the transition to DNA-amino acid era RNA began to be translated to amino acid sequences.