Bayesian phylogenetic analyses of cohesin complex proteins. (a) Phylogeny of SMC family proteins based on an alignment of 255 amino acids. Parameter means: α = 1.75, pI = 0.036 and lnL = -23686.88. (b) Phylogeny of RAD21 and REC8 proteins based on an alignment of 141 amino acids. Parameter means: α = 1.86, pI = 0.033 and lnL = -10212.86. (c) Phylogeny of stromal antigen (SA) proteins based on an alignment of 651 amino acids. Parameter means: a = 3.06, pI – 0.01 and lnL = -34655.82. For all analyses, the tree shown is a consensus of 951 best trees. Blue, red and green names indicate animals, fungi and plants, respectively. 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.