
Amino acids (n = 21)

Codons (n = 64)



Archaea/bacteria

Eukaryotes

Archaea/bacteria

Eukaryotes



Slope

Intercept

Slope

Intercept

Slope

Intercept

Slope

Intercept


Slope



0.95



0.96



0.90



0.91

Correlation coefficient

0.92

0.96

0.96

0.98

0.90

0.97

0.94

0.94

 All pairs of measures are highly correlated. Critical values: for amino acids (n = 21 including stop codons), r of 0.9 corresponds to P = 3 × 10 ^{8}. For codons (n = 64), r of 0.9 corresponds to P = 5 × 10^{24}. The x intercept is transformed as x' = 1/(50%  x) to minimize the effects of extreme values with large errors: this occurs for codons and amino acids with very flat slopes.