the Canterbury Tales. Nature, 394: 839 8 Geoffrey Chaucer’s The Canterbury Tales survives in about 80 different manu- script versions1. We have used the tech- niques of evolutionary biology to produce what is, in effect, a phylogenetic tree show- ing the relationships between 58 extant fifteenth-century manuscripts of “The Wife of Bath’s Prologue” from The Canterbury Tales. We found that many of the manu- scripts fall into separate groups sharing dis- tinct ancestors. Manuscripts such as these were created by copying, directly or indirectly, from the original material (written, in the case of The Canterbury Tales, in the late fourteenth cen- tury). In the process of copying, the scribes made (deliberately or otherwise) changes, which were themselves copied. Textual scholars have developed a system for recon- structing the relationships between textual traditions by analysing the distribution of these shared changes, and have constructed family trees (stemmata) on the basis of the results, with the ultimate aim of establishing precisely what the author actually wrote. This analysis is carried out manually and is feasible only for a few manuscripts of short texts. The sheer quantity of information in a tradition the size of The Canterbury Tales defeats any system of manual analysis. However, the principle of historical reconstruction is similar to the computer- ized techniques used by evolutionary biolo- gists to reconstruct phylogenetic trees of different organisms using sequence data. We the 58 manuscripts. Very similar results were given by PAUP (not shown). Several manuscripts form groups (A, B, C/D, E and F), each descended from a single and dis- tinct common ancestor. The remaining 14 manuscripts were removed from the analy- sis shown in Fig. 1, as they were likely to have been copied from more than one exemplar, either by deliberate conflation of readings or by changing the exemplar dur- ing the course of copying. These manu- scripts were identified by comparison of the trees generated with different regions of the text, which showed that their position in the analysis varied dramatically depending on which region was used. The central point is likely to represent the ancestor of the whole notes of passages to be deleted or added, and alternative drafts of sections. In time, this may lead editors to produce a radically different text of The Canterbury Tales. These results also demonstrate the power of applying phylogenetic techniques, and par- ticularly split decomposition, to the study of large numbers of different versions of sizeable texts. Adrian C. Barbrook, Christopher J. Howe Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK e-mail:
[email protected] Norman Blake Humanities Research Institute, Arts Tower, University of Sheffield, The phylogeny of The CanterburyTales scientific correspondence Figure 1 SplitsTree analy- sis of 44 manuscripts of “The Wife of Bath’s Pro- logue” from Chaucer’s The Canterbury Tales4. The two- or three-char- acter codes indicate individual manuscripts, whereas the large capi- tals indicate groups of manuscripts, which are coloured the same. Nl Cx1 Ry1 Ds Bo1 He Ii Ln En3 Tc2 Ph2 Si Ne Mg Pw Gg Ry2 Tc1 En1 Ma Ra3 Ha5 Sl1 Ht Cn Fi Ld1 Lc Bw Dd Cp Ad1 To Sl2 La Ld2 Ph3 Mm Ad3 Dl Ch Bo2 Hg E O C /D A B F O O 生物の系統推定と 同じソフトウェア を用いて写本の系 統樹(PAUP 3.1) と系統ネットワー ク(SplitsTree)を 推定した. PTLNOM