Simultaneous analysis of the basal lineages of Hymenoptera (Insecta) using sensitivity analysis

The first simultaneous analysis of molecular and morphological data of basal hymenopterans that includes exemplars from all families is presented. DNA sequences (of approximately 2000–2700 bp for each taxon) from the nuclear genes 18S and 28S and the mitochondrial genes 16S and CO1 have been sequenced for 39 taxa (four outgroup taxa, 29 symphytans, and six apocritans). These DNA sequences and 236 morphological characters from Vihelmsen [Zool. J. Linnean Soc. 131 (2001) 393] were analyzed separately as well as simultaneously. All analyses were performed on unaligned sequences, using the optimization alignment ( direct opti-mization) method. Sensitivity analysis sensu Wheeler [Syst. Biol. 44 (1995) 321] was applied by analyzing the data under nine different combinations of analysis parameter values. The superfamily level relationships of basal hymenopterans as proposed by