Sequence selection methods. A sister-pair comprising more speciose (green) and less speciose (red) clades. Coloured taxa indicate those for which sequence data is available. Using our methods, Taxon D is selected for analysis, because its root-to-tip branch is separated from the basal node by 6 nodes, compared to 3 for Taxon L. By contrast Taxon A is selected for analysis using our methods because its root-to-tip branch is separated from the basal node by two internal nodes, compared to one for Taxon C. In both cases, a large component of the sequences are shared by other members of the respective clades over the whole molecular branch length, relative to the sister clade.
Goldie et al. BMC Evolutionary Biology 2011 11:286 doi:10.1186/1471-2148-11-286