Detecting conflicting phylogenetic signal: a mixture model approach with multiple tree topologies

This is a talk given at the New Zealand Phylogenetics Meetings, held in Kaikoura in 2006. The talk describes a likelihood-based mixture model approach that can detect when a sequence alignment supports more than one tree topology. The method finds the topologies and supplies a set of weights that correspond to the number of sites in the alignment that support each topology. The method is used to illustrate the ecdysozoa versus coelomata controversy in metazoan trees. For a related mixture model see the paper by Pagel and Meade, A phylogenetic mixture model for detecting pattern-heterogeneity in gene sequence or character-state data. Systematic Biology, 53, 571-581, 2004. The software that implements these models is available from Andrew Meade (a.meade@reading.ac.uk).