Rnase PH protein phylogenies reveal an absence of two subunits in Giardia. Gene trees were made to diagram the relatedness of the RNase PH protein amino acid sequences in S. serevisisae, H. sapiens, S. solfataricus, and G. lamblia. Node values shown are out of 100 and nodes with no labels had values below 20. (A) The protein parsimony tree displays relatedness between RNase PH proteins of S. cerevisiae, H. sapiens, and S. solfataricus. The tree is separated into Rrp41-like and Rrp42-like proteins with node values providing moderate support for the inferred clades. (B) Addition of putative Giardia RNase PH proteins results in disrupted clades and reduced bootstrap values.