Molecular phylogenetic tree of the Bmp2/4/16 subfamily. A tree focusing on Bmp2/4/16 based on the ML method assuming the JTT+I+Γ4 model (α= 0.82). 212 amino acid sites were used in the analysis. Support values at nodes are shown in order, bootstrap probabilities in the ML analysis, bootstrap probabilities in the neighbor-joining analysis, and Bayesian posterior probabilities. See Additional file 3: Table S1 for accession IDs of the included sequences.