The corrected parsimony phylogenetic method following Hennig's principle for analyzing morphological characters

In phylogenetic analysis using morphological characters, probability-based methods are increasingly employed compared to the parsimony methods. Due to the high diversity of morphological data, however, realistic models for among-states transitional rates have not been found, unlike in the case of molecular sequences. Parsimony, as a classical philosophical thinking framework, remains a powerful tool for inferring phylogenies using diversified data. In parsimony-based phylogenetic analysis, how to deal with character conflicts is essential. The long-standing numerical method, searching for the tree(s) with the overall fewest evolutionary steps, however, brings in the issue of weighting characters in an unjustifiable way. By standardizing step number changing ranges among different characters, I proposed the corrected parsimony approach and restate it here. How to properly weight characters a priori is a separate issue that requires carefully scrutinizing the biological evidence case by case, as previously emphasized by numbers of scholars, explicitly or implicitly, including Hennig himself.