The Barcode Blog

A mostly scientific blog about short DNA sequences for species identification and discovery. I encourage your commentary. -- Mark Stoeckle

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Some taxonomists begin to worry less

In 21 June 2006 Heredity News and Commentary “DNA barcodes: recent successes and future prospects” Dasmahapatra and Mallet describe the DNA barcoding initiative as “plausible and worthwhile” and conclude that “recent studies convincingly demonstrate the efficacy of DNA barcoding to recover biologically significant groupings or species”. Their generally positive review stumbles near the end with a call “to supplement the mtDNA-based barcode with nuclear barcodes.” This is an impractical proposal of uncertain benefit. First of all, routinely adding a “nuclear barcode”, if one were to be found, would be solving a problem that does not exist, as there are few cases so far in which an mtDNA COI barcode does not distinguish closely-related species. Of course these exceptional cases need further taxonomic study “integrating DNA sequencing, morphology, and ecologic studies”. Secondly, although over 30 years of research demonstrate the broad utility of mtDNA in delimiting animal species, no one has yet identified a nuclear locus that can regularly distinguish closely-related species, as Dasmahapatra and Mallet acknowledge. 

 Most of the topics in their review are analyzed in our 2005 brochure “Barcoding Life, Illustrated” which outlines the benefits and limitations to DNA barcoding, including a section on “Why barcode animals with mitochondrial DNA?” . 

This entry was posted on Monday, July 31st, 2006 at 9:47 pm and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

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Contact: mark.stoeckle@rockefeller.edu

About this site

This web site is an outgrowth of the Taxonomy, DNA, and Barcode of Life meeting held at Banbury Center, Cold Spring Harbor Laboratory, September 9-12, 2003. It is designed and managed by Mark Stoeckle, Perrin Meyer, and Jason Yung at the Program for the Human Environment (PHE) at The Rockefeller University.

About the Program for the Human Environment

The involvement of the Program for the Human Environment in DNA barcoding dates to Jesse Ausubel's attendance in February 2002 at a conference in Nova Scotia organized by the Canadian Center for Marine Biodiversity. At the conference, Paul Hebert presented for the first time his concept of large-scale DNA barcoding for species identification. Impressed by the potential for this technology to address difficult challenges in the Census of Marine Life, Jesse agreed with Paul on encouraging a conference to explore the contribution taxonomy and DNA could make to the Census as well as other large-scale terrestrial efforts. In his capacity as a Program Director of the Sloan Foundation, Jesse turned to the Banbury Conference Center of Cold Spring Harbor Laboratory, whose leader Jan Witkowski prepared a strong proposal to explore both the scientific reliability of barcoding and the processes that might bring it to broad application. Concurrently, PHE researcher Mark Stoeckle began to work with the Hebert lab on analytic studies of barcoding in birds. Our involvement in barcoding now takes 3 forms: assisting the organizational development of the Consortium for the Barcode of Life and the Barcode of Life Initiative; contributing to the scientific development of the field, especially by studies in birds, and contributing to public understanding of the science and technology of barcoding and its applications through improved visualization techniques and preparation of brochures and other broadly accessible means, including this website. While the Sloan Foundation continues to support CBOL through a grant to the Smithsonian Institution, it does not provide financial support for barcoding research itself or support to the PHE for its research in this field.