A retrospective approach to testing the DNA barcoding method

PLoS One. 2013 Nov 11;8(11):e77882. doi: 10.1371/journal.pone.0077882. eCollection 2013.

Abstract

A decade ago, DNA barcoding was proposed as a standardised method for identifying existing species and speeding the discovery of new species. Yet, despite its numerous successes across a range of taxa, its frequent failures have brought into question its accuracy as a short-cut taxonomic method. We use a retrospective approach, applying the method to the classification of New Zealand skinks as it stood in 1977 (primarily based upon morphological characters), and compare it to the current taxonomy reached using both morphological and molecular approaches. For the 1977 dataset, DNA barcoding had moderate-high success in identifying specimens (78-98%), and correctly flagging specimens that have since been confirmed as distinct taxa (77-100%). But most matching methods failed to detect the species complexes that were present in 1977. For the current dataset, there was moderate-high success in identifying specimens (53-99%). For both datasets, the capacity to discover new species was dependent on the methodological approach used. Species delimitation in New Zealand skinks was hindered by the absence of either a local or global barcoding gap, a result of recent speciation events and hybridisation. Whilst DNA barcoding is potentially useful for specimen identification and species discovery in New Zealand skinks, its error rate could hinder the progress of documenting biodiversity in this group. We suggest that integrated taxonomic approaches are more effective at discovering and describing biodiversity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • DNA Barcoding, Taxonomic / methods*
  • Lizards / classification*
  • Lizards / genetics*
  • New Zealand
  • Phylogeny*
  • Species Specificity

Grant support

The study was funded by the Allan Wilson Centre for Molecular Ecology and Evolution, and a University Research Fund grant from Victoria University of Wellington. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.