Just as DNA analysis regularly overturns seemingly solid eyewitness identifications in crime investigations, routine DNA analysis can also help biologists avoid blunders. In 28 August 2007 Mol Ecol, researchers from University of Colorado, New Mexico State University, Pisces Molecular, and Brigham Young University report that over 20 years of restocking efforts in western US aimed at restoring native populations of endangered greenback cutthroat trout Oncorhynchus clarkii stomias have mostly been restocking a non-native, non-endangered subspecies, Colorado River cutthroat trout O. c. pleuriticus. They trace the confusion to repeated introductions beginning in the late 1800s of Colorado River cutthroat trout throughout the native range of greenback cutthroat trout. The authors analyzed mitochondrial (COI, ND2) and nuclear (microsatellites, AFLP) DNA from 365 individuals from 15 locations in 3 major river drainage systems in Colorado and surrounding states. Distinct mtDNA lineages corresponding to each subspecies were corroborated by nuclear microsatellite and AFLP data. For another cautionary tale of repeated misidentification of a widely studied organism, see Siddall and colleagues’ entertaining June 2007 Proc R Soc paper scrutinizing commercially available medicinal leeches sold as Hirudo medicinalis.
How might the future look with routine application of DNA ID as quality control? Incorporating DNA barcode analysis into Tree of Life studies is one useful approach, exemplified by two recent large-scale evolutionary studies published in January and April 2008 Syst Entomol, one on phylogenetic relationships in Saturnid silkmoths, and one on higher-level relationships among 12 families in ‘bombycoid complex’ of Lepidoptera. Both studies analyze COI barcodes of all specimens, “allowing confirmination of their identification for species present in the BOLD reference library and enabling future identifications of organisms whose identity is still pending.”