In search of butterfly origins.

To determine the sister taxon to butterflies, the relationships among the macrolepidopteran superfamilies were investigated using sequence data from the ND1 gene of mitochondrial DNA. Both sequence data and translated amino acids were used. We examined how different models of amino acid evolution (nonadditive) affected the inference of tree topology. We then added previously published sequence data from the 18S and 28S subunits of ribosomal RNA. In most analyses, regardless of data type and treatment, the Hedyloidea is either the sister taxon to butterflies or derived within the butterfly clade. These molecular results are compared to a reanalysis of morphological characteristics. The reanalysis of morphology agrees with Minet's 1991 hypothesis of hedyloid relationships. Analysis of combined molecular and morphology data supports the hypothesis that hedylids are the sister group to butterflies. Scott's hypothesis that hawk moths (Sphingidae) are the sister taxon to butterflies is discounted.