Phylogeny of seven amniotic species. Branch lengths are proportional to dS; the degree of constraint (dN/dS) for each terminal lineage is also indicated (values shown in red). Evolutionary rates (dS and dN/dS) are median values deriving from 1,452 alignments of simple one-to-one orthologues present in each species.
Rands et al. BMC Genomics 2013 14:95 doi:10.1186/1471-2164-14-95