Originally posted on sciy.org by Ron Anastasia on Sun 18 Feb 2007 11:11 PM PST
New Bird and Bat Species Found By Barcoding DNA
GUELPH, Ontario, Canada, February 19, 2007 (ENS) -
Scientists have developed a new technique for species identification -
a DNA barcode. Similar to the barcodes that identify consumer products,
species barcodes identify unique animals or plants.
Now, taking the use of DNA barcoding to a more complex level, an international team of scientists reports assembling a barcoded genetic portrait of bird life in the United States and Canada - the prelude to a genetic portrait of all animal life on Earth.
Based on DNA barcode identifiers, the scientists have discovered 15 new genetically distinct species, nearly indistinguishable to human eyes and ears and thus overlooked in centuries of bird studies.
The barcoders also logged the DNA attributes of 87 bat species in the South American country of Guyana and reveal six new species, each characterized by its unique genetic make-up.
"People have watched birds for so long we might think every different tweet has been heard, every different color form observed," says Dr. Paul Hebert of the Biodiversity Institute of Ontario at Guelph University, who co-authored both the bird and bat papers. "However, there are a number of cases of deep genetic divergences within what are currently called single species."
Heron with its barcode (Photo courtesy Biodiversity Institute of Ontario)
"Now, with the vast majority, 93-94 percent, of birds on the continent barcoded it's hard to argue that barcoding might work for the easy stuff but miss the difficult cases of closely-related taxa," Dr. Hebert said.Dr. Mark Stoeckle of New York's Rockefeller University's Program for the Human Environment, a co-author of the bird paper, predicts that, at a global scale, DNA barcoding will distinguish at least 1,000 new species.
The world recognizes about 10,000 bird species today. The researchers hope to complete an all-bird DNA inventory by 2011.
Given the continent's legions of bird specialists, Dr. Stoeckle says he was surprised by the extent of "hidden diversity" revealed in North America, and by the clear DNA distinctions between species. Yet at the same time he points out that there is no universal scientific agreement on what defines a species.
"Perhaps the biggest surprise is that DNA barcoding works as well as it does, that a relatively short code of genes distinguishes species so clearly and there isn't more blurring between species," said Dr. Stoeckle.
"This work is raising questions about how evolution works and what species are," he said.
Professor Paul Hebert is director of the Biodiversity Institute of Ontario in the Department of Integrative Biology at the University of Guelph. He is head of Digital Media and Analysis, and lead investigator of the Canadian Barcode of Life Network. (Photo courtesy BIO)
"Did we find concordance between barcode results and conventional taxonomy? asked Dr. Hebert. "The answer is, resoundingly, yes. In 95 percent of cases, entities recognized as species are barcode distinct.""For cases where it is not convenient to identify species based on shape, sound and color, even non-experts could identify them based on DNA strings," he said.
Barcoding can identify a species from small specimens. When fully established, the barcode database will help quickly identify undesirable animal or plant material in food and detect regulated species in the marketplace.
In a few years, field researchers and wildlife watchers could use hand-held DNA devices for nearly instant species identification.
Once minaturized, the many potential uses of quick DNA barcoding include identifying genetically modified trees or food crops. A DNA barcoder could name the vegetables in a bowl of soup.
Barcoders could be used for certification of species for market, controlling pest animals, and preventing invasions of species through international trade.
The work with birds and bats also helps make aviation safe and is supported in part by the U.S. Federal Aviation Authority and U.S. Air Force.
Crash of a Cessa 172 just 1.7 miles west of Areo County Airport, Frisco, Texas July 8, 2003 after a bird struck the aircraft. The instructor pilot and student suffered fatal injuries. (Photo courtesy FAA)
"Knowing which birds are most often struck, and the timing, altitude and routes of their migrations, could avert some of the thousands of annual collisions between birds and aircraft, military and civilian." said Co-author Carla Dove of the Smithsonian Institution's National Museum of Natural History in Washington, DC.So far, the Barcode of Life Data Systems has catalogued more than 25,000 species of all types, and over 200,000 individual records; both numbers more than doubled in the past year.
Whenever possible, museum specimens have been used to create the DNA barcode reference library, enabling scientists to re-check and verify any puzzling results.
Working from a museum specimen, the Smithsonian has barcoded an ivory-billed woodpecker preserved from decades ago. "If birdwatchers now find a fresh feather, we could strongly confirm the bird still survives," said Dr. Hebert.
The researchers are seeking US$100 million to create 10 million records of 500,000 animal species by 2014.
Says Dr. Hebert, "What it will mean effectively is that researchers will find a barcode linked to just about anything encountered anywhere on the planet.
By 2014 I think you can count on having a functional barcode library linking barcodes to the binomial names that link to the accumulated knowledge about them. And I think you can count on having a handheld device.
"Our job is to reveal how many species there are on the planet and provide really simple tools to tell one species from another."
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