Phylogenomic relationships between lophotrochozoan phyla – phylogenetic signal versus systematic errors

Bernhard Hausdorf (University of Hamburg)

One of the major rearrangements of the animal phylogeny based on molecular data was the shift of the lophophorate lineages from the base of Deuterostomia into Protostomia, where they were amalgamated with phyla characterized by trochophora larvae and/or spiralian cleavage to form Lophotrochozoa. Although the existence of this assemblage of phyla has been affirmed by various molecular data, their interrelationships remained puzzling. In the past years, especially phylogenomic analyses suggested new hypotheses about the relationships between lophotrochozoan phyla like Kryptozoa uniting Nemertea, Brachiopoda and Phoronida and resurrected old ones like the classical Bryozoa including Ectoprocta, Entoprocta and Cycliophora. The reliability of such hypotheses is discussed in consideration of bias in compositional heterogeneity of sequences and in substitution rates between taxa that may cause systematic errors in phylogenetic inference.