JENNER, RA; University of Cambridge: Challenging received wisdom: integrating the new microscopy with the new animal phylogeny

Many of the ideas about the broad pattern of animal evolution that have been accepted as textbook knowledge for a long time are currently being fundamentally revised. Although molecular phylogenetics has been the main impetus for these revisions, comparative morphology proves to be indispensable for fleshing out our new understanding of animal evolution. I will discuss several examples where molecular phylogenetics and new morphological studies have interacted to produce a new understanding of animal body plan evolution. The examples range from the evolutionary significance of different sources of mesoderm and the supposedly fundamental dichotomy between protostomes and deuterostomes, to the phylogenetic placement of the phoronids and brachiopods, the phylogeny of arthropods, and the phylogenetic placement of �problematica� such as the myzostomids.