Dante's Monarchia as a test case for the use of phylogenetic methods in stemmatic analysis

Dante's Monarchia, a fourteenth century treatise on political theory which survives in 20 manuscripts and the editio princeps, has been studied extensively by scholars using traditional analytical methods to establish textual transmission. It was selected as a suitable tradition for a blind study to test the application of computer-based phylogenetic methods to the stemmatic analysis of manuscript relationships. Our results show that these methods-maximum parsimony, NeighborNet and the Supernetwork algorithm-are capable of producing stemmata in very close agreement with those produced by traditional stemmatic analysis, including the identification of texts that change exemplar in the course of copying. The phylogenetic methods can correctly indicate the affiliations both before and after the point of exemplar change. The maximum chi-squared method (developed to detect recombination in DNA sequences) is able to indicate the region of exemplar change, allowing the precise location to be ascertained by textual analysis.