Figure 1. Nucleotide and amino acid composition of the dataset used in this study.

A) Bar graph displaying the percentage of A+T in the concatenation of the nucleotide sequences. B) Reduced dimensionality plot showing the main principal components of the global amino acid compositions. Dots are coloured as in Figure 1A. The group of overlapping dots at the bottom right corner contains the species with the lowest A+T %. The variances that explain the two first axes are respectively 92.3% and 6.3%.