PROGRESS TOWARD A MOLECULAR PHYLOGENY OF THE CENTIPEDE ORDERS (CHILOPODA)

This paper reports results from a preliminary molecular systematic ana lysis of the chilopod orders. Nucleotide sequences from a slowly evolv ing nuclear protein-coding gene, elongation factor-1 alpha, were obtai ned from five centipedes representing the four principal chilopod orde rs and from five outgroup taxa. Maximum-parsimony analysis of inferred amino-acid sequences indicated that geophilomorphs form the sister gr oup to the remaining orders and that lithobiomorphs are the sister gro up to a clade comprising scolopendromorphs and scutigeromorphs. This c onclusion conflicts with the widely held view that scutigeromorphs are the sister group to the other chilopods and that lithobiomorphs form a sister group to the epimorphic orders. Possible explanations for the incompatibility of the morphology-based and molecule-based trees are discussed, and a brief description of ongoing work is presented.