Fig. 2
The distribution and the statistical analysis of the FSSs for the alternative genetic codes. A The frequencies of occurrence of the FSSs in the random codon tables and the compatible codon tables. B The means and standard deviations of the sum FSSs of different types of genetic codes. T-tests indicate that the sum FSS of the NGC is significantly higher than the mean FSS of the random or compatible genetic codes in all six comparisons (Pāāā0) (Table S3). NGC: natural genetic code; FSSs were calculated using matrices PAM250, BLOSSUM62, and GON250. The probability densities were computed using a normal distribution function, and the diagrams were plotted in the language R