Bayesian phylogeny of opisthokonts based on the analysis of 80 complete or nearly complete SSU rRNA gene sequences (1,395 positions), including 28 selected environmental phylotypes (indicated in bold). The number of phylotypes belonging to each opisthokont lineage is indicated in brackets next to the clade name. An as yet undetermined lineage is highlighted in blue. The tree is rooted with five amoebozoan sequences. 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. All branches are drawn to scale.