PHYLOGENETIC SUPERTREES - ASSEMBLING THE TREES OF LIFE

Systematists and comparative biologists commonly want to make statemen ts about relationships among taxa that have never been collectively in cluded in any single phylogenetic analysis. Construction of phylogenet ic 'supertrees' provides one solution. Supertrees are estimates of phy logeny assembled from sets of smaller estimates (source trees) sharing some but not necessarily all their taxa in common. If certain conditi ons are met, supertrees can retain all or most of the information from the source trees and also make novel statements about relationships o f taxa that do not co-occur on any one source tree. Supertrees have co mmonly keen constructed using subjective and informal approaches, but several explicit approaches have recently been proposed.