Bayesian phylogenetic analysis of Argonaute family proteins in the PIWI and AGO subfamilies. Phylogeny is based on an alignment of 714 amino acids and the tree shown is a consensus of 951 best trees. Parameter means: α = 2.13, pI = 0.01 and lnL = -54179.80. Thickened branches refer to posterior probabilities from 0.95 to 1.0. Protein identifiers for D. pulex sequences (in bold) are in Additional File 2.