Universal tree of life (uToL) and proteomic diversity. A. One optimal most parsimonious phylogenomic tree describing the evolution of 200 proteomes (50 each from Archaea, Bacteria, and Eukarya and viruses; virus families are listed in Table 2) generated using the census of abundance of 1,739 FSFs (1,517 parsimoniously informative sites; 62,061 steps; CI = 0.156; RI = 0.804; g1 = −0.325). Terminal leaves of viruses (V), Archaea (A), Eukarya (E) and Bacteria (B) were labeled in red, blue, black and green respectively Numbers on the branches indicate bootstrap values. B. FSF diversity (number of distinct FSFs in a proteome) plotted against FSF abundance (total number of FSFs that are encoded) for 200 proteomes. Major families/phyla/kingdoms are labeled. Both axes are in logarithmic scale.