Evolution of the genetic code

The origin of the genetic code is not merely an evolutionary juggling of codon assignments until some optimal configuration is achieved. I t is, rather, the more interesting and profound problem of how codon assignments arose. This is part and parcel of the origin of a translating mechanism. A plausible scheme for the evolution of translation starting from a simple class of nucleic acid components is presented. Such an evolution may appear unique, idiosyncratic, when viewed only in terms of structural details. However, in its general features, on a more fundamental level, this evolution is a prototype study in the refinement of a process, in the emergence of macro-order. In approaching the evolution of the genetic code the biologist will be forced to reexamine many of his fundamental prejudices, indeed, the meaning of Biology itself.