J. HYM. RES. 1(1), 1992 pp. 63-79 The Application of Nucleotide Sequence Data to Phylogeny of the Hymenoptera: A Review S. A. Cameron, J.N. Derr, A.D. Austin, J.B. Woolley and R.A. Wharton (SAC) Department of Biology, Washington University, St. Louis, Missouri 63130-4899 U.S.A. 1 ; (JND, JBW, RAW) Department of Entomology, Texas A & M University, College Station, Texas 77843-2475 U.S.A.; (ADA) Department of Crop Protection, Waite Campus, University of Adelaide, Glen Osmond, S.A. 5064 Australia. Abstract . — The application of molecular sequence data to studies on the phylogeny of the Hymenoptera are reviewed, with special attention given to the relationships among the higher levels of the Order. Methods for obtaining sequence information from nuclear-encoded ribosomal RNA (rRNA) and mitochondrial rRNA and protein-coding genes are described. Techniques for alignment and phylogenetic analysis of sequences are discussed, as are issues associated with the selection of outgroups. Recent molecular investigations of hymenopteran phylogeny at several taxonomic levels are discussed to illustrate the application of methods and analytical procedures. The use of DNA sequence data for systematics is recent and controversial. The controversies are not about whether nucleotide sequences are ap-propriate for reconstructing phylogenetic history but rather, how they should be used. Therefore, the springboard for our review is not a justification of the relative merits of sequence data over the appli-cation of other techniques for phylogenetic analy-sis (for this see Hillis and Moritz 1990), instead we begin with a discussion of the areas of controversy that have arisen with the use of DNA sequences for phylogenetic analysis. We review each of these issues and make recommendations based in part on our own experiences with collecting and ana-lyzing DNA sequences of Hymenoptera. Differences of opinion have arisen over aspects of sequence data collection and analysis, including (1 ) the appropriate genes (or gene fragments) to be sequenced and their use for different levels of inference; (2) methods of data acquisition; (3) methods of alignment, character weighting, and tree-building; (4) assumptions (or the lack thereof) of the models of nucleotide evolution; (5) consider-ation of molecular secondary structure and the degree to which it can bias interpretation of se-quence data for phylogenetic reconstruction; and (6) appropriate statistical analyses for estimating the reliability of molecular phylogenies. Each of these issues confronts all systematists who wish to approach phylogenetic reconstruction from a mo-1 Current address: Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas 72701, U.S.A. lecular perspective, altogether a non-trivial pur-suit for beginner and experienced alike. This paper arose from the symposium 'Phylog-eny of the Hymenoptera', which was featured dur-ing the 2nd Quadrennial meeting of the Interna-tional Society of Hymenopterists, held in August, 1991 in Sheffield, England. Three contributions in the symposium presented results of phylogenetic analyses using DNA sequences. It become clear at this meeting that many of our audience were unfa-miliar with the use of sequence data for systematic studies. In the future, systematists will have to interpret critically the results from molecular studies in order to compare them effectively with their own investigations based on morphology or other types of data. Therefore, we thought it worthwhile to review the subject of molecular phylogeny with particular reference to the Hym-enoptera. To remain faithful to the theme of the symposium, we primarily restrict our discussion in this review to questions of higher level phylog-eny, that is, to the tribal level or above. However, we include a single study of relationships at the species level. Given that little has been published on comparative DNA sequences for phylogenetic reconstruction of the Hymenoptera (but see Cameron 1991; Garnery et al. 1991; Sheppard and McPheron 1991), we rely heavily on our own in-vestigations of sequence comparisons of the small (18S) subunit ribosomal RNA gene (rRNA) and the large (16S) rRNA gene encoded by the mitochon-drial genome (mtDN A). For a general review of the field of molecular systematics we recommend two
BioStor
