REGULAR ARTICLES

• 18S Ribosomal RNA and Tetrapod Phylogeny – Xuhua Xia, Zheng Xie and Karl M. Kjer
  
  
• The Value of Idiosyncratic Markers and Changes to Conserved tRNA Sequences from the Mitochondrial Genome of Hard Ticks (Acari: Ixodida: Ixodidae) for Phylogenetic Inference – Anna Murrell, Nick J. H. Campbell and Stephen C. Barker
  
  
• Phylogeny and Evolution of Calcareous Sponges: Monophyly of Calcinea and Calcaronea, High Level of Morphological Homoplasy, and the Primitive Nature of Axial Symmetry – Michael Manuel, Carole Borchiellini, Eliane Alivon, Yannick Le Parco, Jean Vacelet and Nicole Boury-Esnault
  
  
• The Systematic Utility of Floral and Vegetative Fragrance in Two Genera of Nyctaginaceae – Rachel A. Levin, Lucinda A. McDade and Robert A. Raguso
  
  
• Failed Refutations: Further Comments on Parsimony and Likelihood Methods and Their Relationship to Popper's Degree of Corroboration – Kevin De Queiroz and Steven Poe
  
  
• Accelerated Likelihood Surface Exploration: The Likelihood Ratchet – R. A. Vos
  
  
• Ancient Allopolyploid Speciation in Geinae (Rosaceae): Evidence from Nuclear Granule-Bound Starch Synthase (GBSSI) Gene Sequences – Jenny E. E. Smedmark, Torsten Eriksson, Rodger C. Evans and Christopher S. Campbell
  
  
• True and False Gharials: A Nuclear Gene Phylogeny of Crocodylia – John Harshman, Christopher J. Huddleston, Jonathan P. Bollback, Thomas J. Parsons and Michael J. Braun
  
  
• Combined Support for Wholesale Taxic Atavism in Gavialine Crocodylians – John Gatesy, George Amato, Mark Norell, Rob Desalle and Cheryl Hayashi
  Gatesy et al. DATA FILE
  
  

POINTS OF VIEW

• Evaluation of the Strategy of Long-Branch Subdivision to Improve the Accuracy of Phylogenetic Methods – Steven Poe
  
  
• The Taxonomic Impediment Overcome: NSF's Partnerships for Enhancing Expertise in Taxonomy (PEET) as a Model – James E. Rodman and Jeannine H. Cody