Abstract
The present-day genetic code, while universal, is not the result of a “frozen accident”, but has evolved over time. Analysis of amino-acid frequency has recently identified amino acids that were recruited early and late into the genetic code. We use this observation to lend support to a hypothesis that the current quaternary triplet genetic code comes from an earlier quaternary doublet code, and before that from a binary singlet code.
Keywords: Evolution, genetic code, binary code, code capture, triplet, codons, aminoacids, Amino-acid gain, Doublet Code, Amino acid frequency, Frozen accident, Quaternary triplet genetic, Triplet code, Nucleotides, Hypothetical primordial, Jordan's gainers, Singlet genetic code, Triplet slots, Hydrophathy character, TAL-type III, Doublet codons