One of the most fundamental problems in biology and artificial life is the definition and understanding of "the gene". As pointed out by Carl Woese, whose work provides a very strong motivation for this study, this problem continues to contribute to much debate between classical biologists who understand "the gene to be defined by the genotype-phenotype relationship, by gene expression as well as gene replication" and many molecular biologists who declared the problem to be solved when the Watson-Crick structure of DNA clearly revealed the mechanism of gene replication . Woese strongly argues against fundamentalist reductionism and presents the real problem of the gene as "how the genotype-phenotype relationship had come to be". In other words, the main question is how the mechanism of translation evolved.
The studies of Piraveenan et al. , Polani et al. , and Prokopenko et al.  considered a model for evolutionary dynamics in the vicinity of the "coding threshold": the transition when the capacity to symbolically represent nucleic acid sequences emerged in response to a change in environmental conditions. The model allows to identify conditions under which a separation between a proto-cell and its symbolic encoding becomes beneficial in terms of preserving the information within a noisy environment. Although evolutionary processes involve a large number of drives and constraints, information fidelity (i.e. preservation) is a consistent motif throughout biology: e.g., modern evolution operates close to the error threshold , and biological sensorimotor equipment typically exhausts the available informatory capacity (under given constraints) close to the limit . Adami, in fact, argues that the evolutionary process extracts valuable information and stores it in the genes . Since this process is relatively slow , it is a selective advantage to preserve this information, once captured.
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