Phylogenetic position of Calkinsia aureus within eukaryotes as inferred from SSU rRNA gene sequences. Maximum likelihood (ML) analysis of 38 taxa sampled from phylogenetically diverse eukaryotes. This tree is rooted with opisthokont sequences. ML bootstrap values greater than 50% are shown. Thick branches indicate Bayesian posterior probabilities over 0.95. GenBank accession numbers of the sequences analyzed are shown in parentheses.