Fig. 3

Molecular phylogenetic reconstruction of the C-type natriuretic peptide gene showing the convergent evolution of C-terminal tail not present in the ancestral toxin, and the subsequent elapid-specific explosive duplication and diversification of this derived trait. Additional files contain sequence alignment used for constructing phylogenetic tree (Additional file 5), tree output file (Additional file 6), and zoomable high-resolution tree image (Additional file 7)