Patterns of speciation and limits to phylogenetic resolution

Trends Ecol Evol. 1994 Mar;9(3):104-7. doi: 10.1016/0169-5347(94)90207-0.


The practice of phylogenetic systematics frequently Includes the assumption that cladogenesis occurs by a series of bifurcations. Consequently, a phylogenetic tree that includes one or more polytomous nodes is generally viewed as unresolved. However, while some polytomles surely represent a failure of resolution, others may be real or the best resolution that can be achieved. Therefore, polytomies should be considered as phylogenetic hypotheses in the same way as bifurcating topologies.