Who Will Actually Use DNA Barcoding and What Will It Cost?

Abstract

It is likely that the mere use of the word barcode is responsible for much of the appeal surrounding DNA barcoding, after all DNA-based identification methods (e.g., DeSalle and Birstein, 1996) used prior to Hebert et al.’s (2002) proposal of the term failed to ignite significant attention from the scientific community and none whatsoever from the general public. The term itself is loaded. Product barcodes are scanned using checkout lasers and indeed the image of the “Star Trek tricorder,” a handheld scanner, has been used repeatedly by barcoding proponents in both presentations and papers (Janzen, 2004; Smith, 2005). Savolainen et al. (2005) use just such an allusion to commence their introductory paper of a special issue of Philosophical Transactions of the Royal Society of London devoted to DNA barcoding. Although the need for scanners capable of detecting biological weapons will undoubtedly lead to the development of portable DNA scanners at some point (a stated objective of the U.S. Department of Homeland Security, Directorate for Science and Technology), there is, however, absolutely no indication that they will be affordable or practical for the kinds of mass identification uses that barcoding proponents are selling to the general public as the outcome of this research. Further, a critical difference between a “tricorder” and a portable DNA barcoder would be the DNA component. Whereas Mr. Spock need only wave his tricorder in the general direction of an alien to be told what it is, real-world barcoders will need to actually handle that animal, remove tissue from it, and load it into the barcoder to get an identification. DNA barcoding is intrinsically linked to specimens as samples that must be collected for DNA extraction, be it in a molecular biology laboratory as at present or by a handheld barcoder at some point in the future. This small detail neatly circumscribes what barcoding can, and what it can’t, achieve. Who then would use DNA barcoding? Dan Janzen has written eloquently and spoken passionately about the need to improve biological literacy amongst the general public and that without the ability to “read” nature by identifying its contents, biodiversity is doomed to be underappreciated and so destroyed (see Janzen et al., 2005, for full development of this argument). One wonders what the place for even a portable DNA barcoder is in this vision. The majority of the public observes nature; they don’t sample it by removing the legs from butterflies and throwing them into a barcoder to get identifications. Wildlife protection authorities expend a lot of effort trying to keep people away from wildlife and certainly not handling or vivisecting them. Will the advent of a portable barcoder result in a complete turn around by wildlife authorities encouraging the wholesale handling of wildlife by the public? For smaller or more delicate plants and animals (which would include those most difficult for an interested amateur to identify without a barcode), being “identified” with a barcoder is likely to be fatal. Not simply due to the handling or picking necessarily, but due to the dissection necessary to get a tissue sample. Further, such barcode identifications will not share the benefits of traditionally collected specimens because an inexperienced member of the public is likely to be simply, and passingly curious, and not inclined to retain each “specimen” as a voucher with rigorous locality data for future study or reference. Although proponents suggest to compensate new species vouchers with free identifications (Janzen, 2004), one needs only think of the vast majority of people who toss aside cans they could recycle for a refund. The inconvenience of handling and sending a specimen in decent condition is far greater than recycling. Clearly such barcodes are unlikely to inspire or benefit the vast majority that needs to be reached to protect biodiversity. Amongst the wider public, the largest group identifying species on a regular basis is birdwatchers. DNA barcoding will be of limited use to them unless it is proposed that a 12-gauge shotgun now become standard equipment for such “twitchers.” Even for professional bird identifications, such as those prepared for biological impact studies, trapping is secondary to visual identifications due to the stress that handling inflicts on birds. Mammal identification for the general public is based on direct visual identifications as well as the interpretation of trail signs, scats, or hair. Perhaps some identifications could come through