 The book, "Foundations of Systematics and Biogeography" by David Williams and Malte Ebach provides a thoughtful history of the origins of this point of view.The traditional approach to cladistics, which traces back to Willi Hennig, groups together organisms based on whether or not they share derived characters or character states that are assumed to be descended from a common ancestor.Transformed cladists maintain that the assumption of common descent is uninformative and/or potentially misleading, and that therefore cladistic methods should be free from evolutionary process assumptions, and based only on parsimonious interpretation of empirical data