Abstract
‘The evolutionary tree of animals’ charts the changing views on Animal Kingdom classification from Ernst Haeckel's earliest evolutionary trees in the 1860s to the more modern Coelomata hypothesis. Rudolf Raff's 1988 gene sequence data study marked the beginning of a revolution in using DNA sequence information to hunt for the true animal phylogenetic tree. One conclusion was clear: the segmented annelids and segmented arthropods had very different ribosomal RNA gene sequences; there was no evidence supporting the Articulata group. The new animal phylogeny has the four non-bilaterian phyla branching early in animal evolution, leaving the large group of Bilateria. The bilaterians then divide into the three great superphyla, Deuterostomia, Ecdysozoa, and Lophotrochozoa.
