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Cladistics is a technique borrowed from biology, where it was originally named phylogenetic systematics by Willi Hennig. In biology, the technique is used to determine the evolutionary relationships between different species. In its application in textual criticism, the text of a number of different manuscripts is entered into a computer, which records all the differences between them. The manuscripts are then grouped according to their shared characteristics. The difference between cladistics and more traditional forms of statistical analysis is that, rather than simply arranging the manuscripts into rough groupings according to their overall similarity, cladistics assumes that they are part of a branching family tree and uses that assumption to derive relationships between them. This makes it more like an automated approach to stemmatics. However, where there is a difference, the computer does not attempt to decide which reading is closer to the original text, and so does not indicate which branch of the tree is the "root"which manuscript tradition is closest to the original. Other types of evidence must be used for that purpose.

What is the biological basis for Cladistics?
to determine the evolutionary relationships between different species