Three-taxon analysis can always successfully recognize groups based on putative reversals
- Published
- Accepted
- Subject Areas
- Evolutionary Studies, Taxonomy, Computational Science
- Keywords
- Cladistics, three-taxon analysis, Parsimony, three-taxon statements, reversals
- Copyright
- © 2015 Mavrodiev
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2015. Three-taxon analysis can always successfully recognize groups based on putative reversals. PeerJ PrePrints 3:e979v1 https://doi.org/10.7287/peerj.preprints.979v1
Abstract
Three-taxon analysis in it canonical form can always successfully recognize groups based on putative reversals if latter are coded as separate states before three-taxon permutations are derived from conventional matrices. This way of coding removes incongruence from either conventional multistate or three-taxon matrices and makes the discussions about symplesiomorphy as a putative homology unnecessary. The ability of conventional parsimony to recognize reversal-based clades is technically nothing more than grouping by plesiomorphic values. Therefore this solution cannot be accepted as a Cladistic approach to data and must be correctly classified as “post-Hennigian” or “phenetic”. The ability of three-taxon analysis to recognize groups based on the putative reversals may be viewed as a heuristic cladistics attempts to prevent this “phenetic” approach affecting the analysis of the data.
Author Comment
The inability to handle putative reversals is general criticism of three-taxon (or three-item) analysis (3TA), one of the two approaches to Cladistics proposed by Nelson & Platnick in 1991. Today 3TA is the only Cladistics method, that avoid grouping by plesiomorphic values. Here I will show that the 3TA in its canonical form can always successfully recognize groups based on putative reversals if the latter are coded as separate states before three-taxon permutations are derived from conventional matrices.