Fig. 6 in A Systematist's Guide to Estimating Bayesian Phylogenies From Morphological Data

Fig. 6. The parsimony length of three characters on a single tree. Each character has been scored for how many changes it exhibits on the displayed tree. Character one is not considered parsimony informative, as every tip on the tree has a different state, and therefore, it cannot be used to discriminate among trees. Character three is non-informative because it has no variation. Character two is considered informative because it favors trees containing one grouping over another. Under parsimony, characters one and three would not be collected. Under a Bayesian model, not observing invariant characters must be corrected for in order to avoid overestimating the true rate of evolutionary change (Lewis 2001).