Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Applying Bayesian Phylogenetic Methods to the Stemmatics of the Divine Comedy

Applying Bayesian Phylogenetic Methods to the Stemmatics of the Divine Comedy

Presentation at the MPI-SHH WIP, December 2019

74ebca07ccf49343d1ddaef84d65b78e?s=128

Tiago Tresoldi

December 05, 2019
Tweet

More Decks by Tiago Tresoldi

Other Decks in Research

Transcript

  1. Applying Bayesian Phylogenetic Methods to the Stemmatics of the Divine

    Comedy Tiago Tresoldi CALC/DLCE/MPI-SHH Jena, 2019-12-05
  2. Stemmatics • "Copies introduce changes" • Developed along with religious

    and legal exegesis (e.g. "witnesses") • Mutation traditionally seen as bad ◦ "truth" of the archetype ◦ "changes" are "errors" to be removed ◦ "purity" and "contamination" • Scientific discipline developed in the same cultural framework of evolutionary biology and historical linguistics ◦ Karl Lachmann (1793-1851) ◦ Joseph Bédier (1864-1938) • Adoption of phylogenetics has been slow ◦ "New stemmatics" (Bordalejo 2006; Robinson 2016) ◦ "éloge de la variante" (Cerquiglini 1989) First actual stemma (Schlyter and Collins, 1827)
  3. Learn stemmatics in one minute! Scheme of descent of the

    manuscripts of Pseudo-Apuleius' Herbarius by Henry E. Sigerist (1927) (Source: "Textual Criticism", Wikipedia)
  4. Text in evolution • Easy to find analogies with biology

    and linguistics (e.g. admixture) • Copying manuscripts is hard ◦ Copyists didn't even necessarily understand what they were writing! • "Agency" of changes and of reconstructions • Manuscripts are not static • Changes are not necessarily independent • Hard polytomies are real, common and expected "Christine de Pizan in her study" in Cent Ballades. British Library, Ms. Harley 4431, f° 4.
  5. Divine Comedy, manuscript Triv Divine Comedy, manuscript Ash

  6. Notes, glosses and corrections by Pietro Alighieri (c. 1350)

  7. Divine Comedy • One of the most successful medieval works

    ◦ More than 600 complete manuscripts ◦ Canterbury Tales at 80 (inc. incomplete ones) • Written between 1306-1321, circulating before conclusion • Read and copied by speakers of different varieties • "Tradition" characterized by intentional "contamination" ◦ The case of Boccaccio ("divina") • "Errors" already in the oldest dated manuscript (Landiano, 1336)
  8. Critical tradition • First scientific approach by Barbi (1891) ◦

    400 loci critici (~ SNPs vs. whole sequencing) • Casella (1921) proposed the first tree(s) • Petrocchi (1965) published the most important edition ◦ Excludes everything that might have been influenced by Boccaccio ◦ Stemmatic, but also practical reasons • Sanguineti (2001) proposed a new tree ◦ Collatio of the full text, but only seven manuscripts ◦ Rb and Urb have a new placement • Shaw (2011) contrasts Sanguineti with a digital edition and phylogenetic analyses
  9. Casella's tree(s)

  10. Critical tradition • First scientific approach by Barbi (1891) ◦

    400 loci critici (~ SNPs vs. whole sequencing) • Casella (1921) proposed the first tree(s) • Petrocchi (1965) published the most important edition ◦ Excludes everything that might have been influenced by Boccaccio ◦ Stemmatic, but also practical reasons • Sanguineti (2001) proposed a new tree ◦ Collatio of the full text, but only seven manuscripts ◦ Rb and Urb have a new placement • Shaw (2011) contrasts Sanguineti with a digital edition and phylogenetic analyses
  11. None
  12. Critical tradition • First scientific approach by Barbi (1891) ◦

    400 loci critici (~ SNPs vs. whole sequencing) • Casella (1921) proposed the first tree(s) • Petrocchi (1965) published the most important edition ◦ Excludes everything that might have been influenced by Boccaccio ◦ Stemmatic, but also practical reasons • Sanguineti (2001) proposed a new tree ◦ Collatio of the full text, but only seven manuscripts ◦ Rb and Urb have a new placement • Shaw (2011) contrasts Sanguineti with a digital edition and phylogenetic analyses
  13. None
  14. Critical tradition • First scientific approach by Barbi (1891) ◦

    400 loci critici (~ SNPs vs. whole sequencing) • Casella (1921) proposed the first tree(s) • Petrocchi (1965) published the most important edition ◦ Excludes everything that might have been influenced by Boccaccio ◦ Stemmatic, but also practical reasons • Sanguineti (2001) proposed a new tree ◦ Collatio of the full text, but only seven manuscripts ◦ Rb and Urb have a new placement • Shaw (2011) contrasts Sanguineti with a digital edition and phylogenetic analyses
  15. None
  16. Many questions • Can we reproduce Petrocchi's tree with Bayesian

    analysis? ◦ Can we support it by using the entire text instead of the 400 loci? • Can we support Sanguineti's tree, especially the relationship between Urb and Rb? • Can we reproduce Shaw's findings with Bayesian analysis? • Is there evidence for an independent tradition for each cantica? • Can we start building a pipeline for: ◦ Incorporating more manuscripts of the Divine Comedy? ◦ Studying other works? Papyrus 52 (oldest fragmentary manuscript of the New Testament)
  17. Data and analysis • Collecting and expanding data from Shaw's

    edition • 34 taxa ◦ 6 (+1) witnesses ◦ layers of correction independently coded ◦ 3 critical editions (Petrocchi, Leonardi, Sanguineti) • 94,782 characters (34,417 sites, 1,487 patterns) • Most characters with either a single state or two states ◦ Not considering orthography ◦ However, in some cases over 10 states • Initial exploratory analyses with Neighbor-nets; Bayesian with BEAST2 ◦ Only seven main manuscripts / all witnesses ◦ The entire text / each cantica independently ◦ 400 loci / the entire text
  18. Example of the raw source data provided by Shaw (2011).

  19. NEXUS

  20. None
  21. Covarion, birth-death, strict clock, global variation, MCMC length 25M, all

    taxa
  22. Covarion, birth-death, strict clock, global variation, MCMC length 25M, selected

    taxa
  23. Covarion, birth-death, relaxed clock, rate variation, MCMC length 500k, selected

    taxa
  24. ASR is hard(er) • In the first canto (NEXUS character

    I_01_048_7), the author describes a terrifying she-wolf walking towards him a. parea che l'aere ne temesse ("as if the air afraid of it [=the she-wolf]") b. parea che l'aere ne tremesse ("as if the air was shaken by it [=the walking]") • Experts' consensus is that it is a "facilitation" of the original, employing the Latinism tremere (Italian has tremare) ◦ Common principle of lectio difficilior potior (the most difficult state is the strongest) ◦ Used by the author elsewhere (e.g. Letter VI, 24, and Rime IV.1-2, where the air is "shaken by a person walking") ◦ Literary critics agree that it fits the tone much better
  25. Higher goals • Problem of the Synoptic Gospels • Evolution

    of religious texts in light of history. For example, in earlier manuscripts: ◦ Mark ends with the death of Jesus (Mark 16:9-20 not found) ◦ Luke 23:34 ("Forgive them, for they know not what they do") is missing ◦ Paul's injunction to women to be "silent" and "subordinate" (1 Cor 14:34-35) is missing
  26. References ALAGHERII, Dantis (2001). Comedìa. Edited by Federico Sanguineti. Firenze:

    Edizioni del Galluzzo. ALIGHIERI, Dante (1994). La Commedia Secondo L’antica Vulgata: Introduzione. Edited by Giorgio Petrocchi. Opere di Dante Alighieri v. 1. Firenze: Le Lettere. BORDALEJO, Barbara (2006). Modern Genetic Methods: the New Stemmatics. http://www.textualscholarship.org/stemmatics/index.html. Accessed on December 4, 2019. CERQUIGLINI, Bernard (1989). Éloge de la variante: histoire critique de la philologie. Aux Travaux. Paris: Éditions du Seuil. HOWE, Christopher J.; CONNOLLY, Ruth; WINDRAM, Heather F. (2012). “Responding to Criticisms of Phylogenetic Methods in Stemmatology.” Studies in English Literature 1500-1900 52 (1): 51 – 67. LEONARDI, Anna M. C. (1991). “Introduzione.” In La Divina Commedia. Milano: Arnoldo Mondadori Editore. MACÉ, Caroline; BARET, Philippe V. (2006). “Why Phylogenetic Methods Work: the Theory of Evolution and Textual Criticism.” Linguistica Computazionale 24: 89 – 108. ROBINSON, Peter (2016). “Four Rules for the Application of Phylogenetics in the Analysis of Textual Traditions.” Digital Scholarship in the Humanities 31 (3): 637 – 651. SHAW, Prue (2011). Commedia: a Digital Edition. Birmingham: Scholarly Digital Editions. TROVATO, Paolo; TONELLO, Elisabetta (2016). “Premessa ai saggi di edizione e di commento di Inferno XXXIV.” Commedia (2). Padova: Libreriauniversitaria.it.
  27. Thank you! Main findings so far: • Phylogenetic analysis supports

    Shaw (and Petrocchi) more than Sanguineti ◦ But it is not so clear-cut • No support for an independent tradition of each cantica • Loci critici seem to perform better than random selections of equivalent size • Evolutionary models are not suitable out-of-the-box ◦ Date-calibration can worsen the results • Probabilities of substitution might depend on character as well as value