Despite the declining number of traditional taxonomists, our knowledge of Earth's biodiversity continues to grow in the form of DNA sequence data. Freely available through online databases, analyses of sequence datasets are increasingly used as an alternative for the traditional taxonomic process. Species identifications have become “DNA barcoding,” new species discoveries are characterised by genetic divergences, and traditional classification has been supplanted by molecular phylogenetics. These developments are illustrated through a case study investigating the identities of Taygetis butterflies of Costa Rica. Here I review prospects and problems with the molecularization of taxonomy and the key role of publicly available nucleotide sequence databases in efforts to catalogue diversity of life.