Cladistic tree balance is the extent to which internal nodes on a clad
istic tree define clades of equal size. More robust maximum-parsimony
trees taken from the literature are more balanced. Simulation studies
suggest that a methodological bias is responsible for this correlation
because incorrect reconstructions are also likely to be less balanced
than the true trees they estimate Misinformative cladistic characters
can be expected to make trees more unbalanced if there is marked vari
ation in their rates of change. This bias may contribute to the excess
of unbalanced phylogenies reported in the literature.