Figure 1.

Model of evolution of the $X$ circular code motifs (Equation (1)) by increasing its cardinality (composition) and decreasing its length. Evolution begins with $X$ motifs of minimal cardinality 1 (long repeated trinucleotides) in genomes (the examples given are extracted from Table 2 in [8]). Then, the mutations in repeated trinucleotides lead to $X$ motifs of low cardinality $<10$ (different and short repeated trinucleotides) in genomes (the examples given are extracted from Table 4 in [8]) up to $X$ motifs of high $\ge 10$ and maximal cardinality 20 coding the 12 amino acids (Equation (2)).