DNA Bar-Coding Could Rewrite Book of Life
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
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,"
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
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
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
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
"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
"Our job is to reveal how many species there are on the planet
and provide really simple tools to tell one species from another,"