Phylogenetic Noise Leads to Unbalanced Cladistic Tree Reconstructions

Cladistic tree balance is the extent to which internal nodes on a cladistic 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 variation in their rates of change. This bias may contribute to the excess of unbalanced phylogenies reported in the literature.