DNA Bar-Coding Could Rewrite Book of Life

Stephen Leahy

BROOKLIN, Canada, Feb 19 (IPS) - Fifteen new species of birds have 
been discovered in North America following the first ever genetic 
analysis of nearly all 690 known species. A similar DNA profiling or 
"bar-coding" of Guyana's 87 bat species revealed an additional six 
genetically distinct bats.

These new species are nearly indistinguishable to human eyes and ears 
from known species but the analysis shows their DNA evolved along 
different paths millions of years previously, according research 
published Sunday in British journal Molecular Ecology Notes.

"DNA bar-coding will transform efforts to protect and conserve the 
world's biodiversity," said Paul Herbert of the Biodiversity 
Institute of Ontario at Canada's University of Guelph.

"You can't protect it if you can't identify it," Herbert told IPS.

The habitat of a North American shorebird called the Solitary 
Sandpiper is under tremendous pressure from land development and 
climate change. It was not previously known to have two distinct 
forms, yet their DNA reveals that two genetically different groups 
diverged about 2.5 million years ago.

"How can you develop strategies to preserve highly different genetic 
entities if you don't know they're there? Our work is providing the 
first molecular evidence of some of these splits," Herbert said.

Protecting and conserving biological diversity is important because 
living organisms play central roles in all ecosystems that provide 
services like clean air and water that all life, including humans, 
depends on. And it is the diversity of interacting species that is 
the key to the health and resilience of ecosystems.

Using DNA to identify species is not new but what Herbert and 
colleagues have developed is a way of standardising the genetic 
analysis so that it can be done quickly and at low cost.

"Three hours and five dollars in chemicals" is all it now takes to 
identify the species from a tissue or feather sample, he said.

DNA is found in all living things and is a complex molecule that 
contains all the genetic instructions for an organism to develop. Not 
surprisingly, the DNA of a human is different and more complex than 
that of a worm -- although mouse DNA is similar to human DNA. The 
genetic differences within the millions of pieces that make up DNA 
among animal species were very hard to find.

After 20 years of searching and several years of testing, sampling 
and other field research, Herbert's breakthrough was the discovery of 
a portion of a gene called cytochrome c oxidase I (COI). COI appears 
to be biology's unique bar code for all animal species.

Port inspectors and wildlife officials will be able to quickly obtain 
genetic identification of a shipment of animal skins or fish filets 
to determine if they come from illegal or endangered species, Herbert 

Airport officials can identify the remains of birds that are 
swallowed, sometimes disastrously by the jet engines of airplanes. 
Many thousands such "bird strikes" occur annually and by identifying 
the species most often running afoul of the engines, officials can 
prevent them from nesting near airports.

The technology is being used to set the boundaries for national parks 
in Madagascar and to learn more about the impacts of development 
pressure in the Amazon rainforest.

Among the many applications, none may be more controversial than 
telling the birding world, including ornithological experts, that 
there are 15 new species of birds in the U.S. and Canada.

"These are 15 overlooked species -- genetically distinct but 
look[ing] the same," said Mark Stoeckle of Rockefeller University in 
New York City and a co-author of the paper in Molecular Ecology Notes.

Considering how well studied North American birds are, that result 
came as a surprise, Stoeckle told IPS.

"Can we use DNA alone to define a species? Perhaps in future, but 
right now we need expert opinion," he said.

Some of those experts have argued previously that this technology 
remains unproven. Species identification and classification is called 
taxonomy, and it has a rich scientific tradition of more than three 
hundred years.

However, the new genetic analysis shows "there are a number of cases 
of deep genetic divergences within what are currently called single 
species," Herbert said.

Even though birds may appear very similar to human observers, a 
species with a distinct DNA barcode very rarely interbreeds; they 
literally find birds of a feather as mates. Also, the fauna (birds 
and bats) newly distinguished by virtue of unique DNA do not yet have 
unique names. That issue and process is the subject of scientific 
discussion and debate.

"We would raise hackles if we said DNA is now the only way to ID 
species," Herbert noted.

Taxonomy, however, is difficult, tedious and painstaking work and 
takes many years to develop expertise.

For example, Stoeckle discovered an unusual centipede while wandering 
in New York's Central Park one day. It took four years of work by 
centipede experts, who happen to be in Italy, to identify it as a new 
species after visually comparing it to all other identified 

DNA bar-coding will make this happen much more quickly, he said.

More importantly, the technology means that nearly all living things 
on the planet could be actually identified. Right now not even all of 
the world's 5,500 mammals have been identified. Biologists estimate 
that there might be two million species on earth, not including 
bacteria and fungi.

Herbert says that in just seven years, they could build a DNA bar 
code "library" that would precisely identify 500,000 animal species 
-- including insects, invertebrates and fish. The cost would be a 
relatively modest 100 million dollars for the Bar Code of Life Data 
Systems and fundraising efforts are underway around the globe. 
Already the Bar Code of Life has catalogued more than 25,000 species.

"What it will mean effectively is that researchers will find a 
barcode linked to just about anything encountered anywhere on the 
planet," Herbert said.

And by then biologists in the field will have a hand-held device, 
akin to a GPS, that will tell them precisely what species any hair or 
feather or insect shell found along a remote jungle trail belongs to.

"Our job is to reveal how many species there are on the planet and 
provide really simple tools to tell one species from another," 
Herbert concluded.