title: Patterns of speciation and limits to phylogenetic resolution.
abstract: 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.
authors.affiliation: Guy Hoelzer is at the Depts of Biology and Environmental Resource Sciences, University of Nevada Reno, Reno, NV 89557, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Hoelzer
authors.forename: D J
authors.initials: DJ
authors.lastname: Meinick