Bayesian phylogeny of eukaryotes based on the analysis of 125 complete or nearly complete SSU rRNA gene sequences (1,175 positions), including 56 selected environmental phylotypes (indicated in bold). The number of phylotypes belonging to each higher-level eukaryotic group is indicated in brackets next to the clade name. Phylotypes previously considered as novel eukaryotic lineages, which are in fact fast-evolving members of known groups, are highlighted in orange. Phylotypes that could be identified thanks to an increasing taxon sampling are highlighted in green. The remaining phylotypes of undetermined taxonomic position are highlighted in blue. The tree is presented with a basal bifurcation between unikonts (Amoebozoa + opisthokonts) and bikonts. The GTR + G model of evolution was used, and the topology shown is a Bayesian consensus of 20,000 sampled trees (see text). The posterior probability of each resolved node is indicated above branches, while numbers under branches represent bootstrap support following 10,000 replicates of a minimum evolution analysis of the same dataset, using maximum likelihood-corrected estimates of the distances (dashes indicate bootstrap values under 50%). Branches are drawn to scale, except those marked with an asterisk (*), which were reduced by half for clarity.