Nov 6, 2009, 17:08 GMT
Washington - Even the most hard-bitten detective knows how DNA analysis can help solve a crime.
Since 2002, investigators of a different kind - biologists - have been using a similar approach to track how global warming is affecting the world's species or identifying a piece of dried meat found on a poacher.
Starting Saturday, 350 international experts plan a week-long meeting in Mexico City to discuss new issues emerging in the rapidly expanding field of DNA barcoding.
At the top of the agenda is how to use barcoding to track the effect of global warming on various species, starting with ancient history and moving through current and future changes, said Paul Hebert, head of the International Barcode of Life Initiative in Guelph, Canada, where barcoding was developed in 2002.
'We need to do it for the planet,' Hebert told the German Press Agency dpa.
Hebert said he was stunned by a recent project that probed the effect of global warming on the shores of the Hudson Bay, on the margin of the Canadian Arctic.
The ice is melting and the 'polar bears are getting thinner,' Hebert said. His team wanted to know about the parallel developments in the insect community. Using a 50-year-old collection of 10 parasitic wasps from the same region as a base for comparison, the team found that all but one of the species had disappeared.
'There's huge turmoil in the insect community,' Hebert said. 'That's a short time span of just 50 years.'
Since its development in 2002, DNA barcoding has been used to identify 100,000 species, mostly animals and insects, using a relatively simple section of DNA that is common to all creatures.
But identifying plants is more complicated, Hebert said. The scientists hope to agree in Mexico on which particular sequences of DNA can be used to sort one plant species from another, an effort that will entail collecting more information than for animals and insects.
Agreement on plant identification is the final step before launching an International Barcode of Life programme by 2010, Hebert said. The goal is to also give DNA barcodes to Earth's 400,000 species. The library will serve as the ultimate biodiversity genomics information base.
With a new 'blender' approach developed at the Guelph institute, scientists have learned to identify species within bio mixtures such as the stomach contents of animals and ice cores taken from million- year-old permafrost.
That's because the DNA in such small crushed segments of material is incredibly robust and identifiable through barcodes, Hebert said.
'We no longer have to stare down microscopes, but we can read the assemblage of thousands of organisms at one time,' he said. 'All of a sudden we have a time machine.'
In some cases, the scientists actually take intact samples of insects or other material and chop them in a blender to make it easier to read the barcodes using special equipment.
Hebert said the fossil DNA from permafrost can shed light on how previous climate changes affected changes in organic life. Likewise, by tracking the stomach contents of animals over the next decades, scientists will be able to see how current global warming is changing animals' habits.
On the law enforcement level, the use of DNA barcoding to catch poachers will also be on the agenda in Mexico City.
The sale of wild African bush meat, including antelope, buffalo, zebra, warthog and wild pig, netted an estimated 15 billion dollars worldwide in 2008, conference organizers said.
When suspects are caught, it is often with dried meat whose origins are almost impossible to identify without barcoding.
The work of endangered species specialists like George Amato of the American Museum of Natural History in New York, who has been working with law enforcement agencies worldwide on the issue, will also be a topic at the Mexico City meeting.
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