Figure 3. Two simple trees of four taxa (A, B, C, D) were used in the parameter sweep.

The star; where all taxa have equal evolutionary distance ℓ to their ancestor and ladder; where the distance to the nearest ancestor decreases in incremental steps of ℓ∕2. For the ladder, the length of the internal branch for taxon B was set equal to the branch length of the star and therefore possesses both more closely and more distantly related community members for any value of the scale factor α_BL relative to the star topology.