Known Knowns, Known Unknowns, Unknown Unknowns and Unknown Knowns in DNA Barcoding: A Comment on Dowton et al.

In a recent commentary, Dowton et al. (2014) propose a framework for “next-generation” DNA barcoding, whereby multi-locus datasets are coupled with coalescent-based species delimitation methods to make specimen identifications. They claim single-locus DNA barcoding is outdated, and a multilocus approach superior, with their assertions supported by an analysis of 33 species of Sarcophaga flesh flies. Here, we reanalyse their data and show that a standard DNA barcode analysis is in fact capable of identifying 99.8% (all but one) of their Sarcophaga specimens, and that their conclusions misrepresent their data. We also discuss the benefits and drawbacks to their vision of “next-gen” barcoding.