Three-taxon analysis

Introduced by Nelson and Platnick in 1991[2] to reconstruct organisms' phylogeny, this method can also be applied to biogeographic areas.

It attempts to reconstruct complex phylogenetic trees by breaking the problem down into simpler chunks.

[3] Once each group of three taxa has been considered, the method constructs a tree that is consistent with as many three-item statements as possible.

[3] From a theoretical point of view, the method has three main problems: (1) character evolution is a priori assumed to be irreversible; (2) 3is that are not logically independent are treated as if they are; (3) 3is that are considered as independent support for a given tree may be mutually exclusive on that tree.

[4] A computer program that implement three-taxon analysis is LisBeth[5] (for systematic and biogeographic studies).