Published by Communications and Public Affairs (519) 824-4120, Ext. 56982 or 53338
February 17, 2003
Professor proposing 'bar coding of life' system to catalogue species
A University of Guelph professor is proposing to “barcode” all species -- much like retail products are now tagged on grocery store aisles -- to identify living things by DNA rather than appearance.
In a paper published in the Proceedings of the Royal Society and reported on in the January issues of Nature and The Economist, Paul Hebert describes how this DNA identification system could be used to identify all animal species on the planet -- including the millions still unknown. He suggests it should represent a powerful augmentation to traditional taxonomy, which is based on identifying species primarily by sight.
“Currently, if people stare long enough at creatures and they have the training, they can recognize species boundaries,” said Hebert, a professor in the Department of Zoology and holder of a Canada Research Chair in Molecular Biodiversity.
“We are saying that there is a need to bring modern technology to the task of species recognition. We also suggest that nature has been kind enough to embed every life form with a ‘barcode’ and all we need to do is read it.” Hebert says that in about 20 years, the “barcoding of life” system could enable the completion of a catalogue of the estimated 10 million species of animals on the planet, of which only 1.2 million have been formally described over the past 250 years.
The retail industry’s coding system employs 10 digits at each of 11 positions to create 100 billion different combinations, or barcodes, that are in turn assigned to specific products ranging from canned tuna to electronics.
DNA is encoded using four chemical bases -- adenine, cytosine, guanine and thymine, and the genomes of most species are millions of these nucleotides long. An examination of only 45 of these nucleotide positions can yield close to a billion “barcodes” that can be used in species recognition, Hebert said.
He and his research colleagues have tested this hypothesis by examining sequence diversity in the gene that codes for a protein that is embedded in the mitochondrial membranes of every cell. Easily identifiable, this protein, called cytochrome c oxidase I (COI), plays a key role in cellular energy production. The team has tested the effectiveness of this COI- based identification system on a broad range of animal life from flatworms to vertebrates.
“In all cases, we obtained 100 per cent success in identification, so we are convinced that we can create an identification system for animal life and possibly all eukaryotes- plants, fungi and protists,” Hebert said.
He added that a comprehensive inventory of animal life is a goal shared by many biologists. Recently, the Alfred P. Sloan Foundation of New York City provided an initial $120,000 to assemble some 40 leading researchers in biodiversity science this coming March. “We are going to talk about establishing an international barcoding network and if the meeting goes well, the Foundation may provide substantial support to aid this enterprise,” he said.
Hebert pointed out that a catalogue of life would be a noble intellectual exercise, even if there was no practical need for it. But in fact, much of Canada’s wealth generation is linked to the management of biological systems. “We grow trees and crops, we deal with disease and pests. All of these activities involve life forms and sometimes the ability to identify species is crucial to management decisions,” he said. For example, the rise of the West Nile virus has led Canadians to recognize that mosquitoes can be disease-bearing. Through a barcoding system, the researchers plan to develop automated DNA-based systems that would make it very easy to identify mosquitoes and determine which species actually bear the virus.
“For these and many, many other reasons, I see a huge imperative to move forward with this inventory,” he said. “Moreover humanity is well on its way to provoking the greatest mass extinction of life in the last 65 million years. This is one science project that simply can’t be delayed.”
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