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[BKARTS] When is a species not a species?
And what impact will this research eventuallly have on gutting the
valuable Endangered Species Acts worldwide?
NORWAY: February 20, 2007
OSLO - Genetic tests of North American birds show what may be 15 new
species including ravens and owls -- look alikes that do not
interbreed and have wrongly had the same name for centuries,
scientists said on Sunday.
If the findings from a study of birds' DNA genetic "barcodes" in the
United States and Canada hold true around the world, there might be
more than 1,000 new species of birds on top of 10,000 identified so
far, they said.
A parallel study of South American bats in Guyana also showed six new
species among 87 surveyed, hinting that human studies of the defining
characteristics of species may have been too superficial to tell
almost identical types apart.
"This is the leading tip of a process that will see the genetic
registration of life on the planet," said Paul Hebert of the
Biodiversity Institute of Ontario, a co-author of the report in the
British Journal Molecular Ecology Notes.
"You can't protect biodiversity if you can't recognise it."
The scientists found 15 potential new species among 643 types of bird
studied from the Arctic to Florida. The sample covers almost all 690
known breeding species in North America.
"North American birds are among the best studied in the world," said
co-author Mark Stoeckle of the Rockefeller University in New York.
"Even in a group where people have been looking very carefully there
are genetically different forms that appear to be new species."
CURVE BILLED THRASHER
Look alike species were of the Northern Fulmar, Solitary Sandpiper,
Western Screech Owl, Warbling Vireo, Mexican Jay, Western Scrub-Jay,
Common Raven, Mountain Chickadee, Bushtit, Winter Wren, Marsh Wren,
Bewick's Wren, Hermit Thrush, Curve Billed Thrasher and Eastern
"It would be a reasonable guess that there are likely to be at least
1,000 genetically distinct forms of birds (worldwide) that will be
recognised as new species," Stoeckle said.
The genetic tests, for instance of a feather, give a readout of a
"barcode" for each creature similar to the black and white parallel
lines on packages at supermarkets.
They said DNA diverged by at least 2.5 percent -- enough, they said,
to define a species despite almost identical shape, plumage and song.
A one percent difference typically indicated a million years without
interbreeding, they said.
The study also found 14 pairs of birds with separate identities that
were almost genetic "twins", two trios of birds were DNA triplets and
eight gull species were almost identical.
"Some of these on close inspection may really be better considered as
a single species," said Stoeckle. "Others are probably very young
species at the borderline."
The Snow Goose and Ross's Goose, for instance, shared 99.8 percent of
DNA and the black-billed magpie and the yellow-billed magpie 99.6
percent. Gulls such as the Glaucous and Iceland Gulls were 99.8
percent the same.
The scientists said there was no clear scientific definition of a
species -- inability to interbreed was often favoured.
"But that's difficult -- we're not watching bats mate in caves, we're
not often watching small life forms," Hebert said.
The scientists are hoping to raise US$100 million to compile a
barcode of life -- 10 million DNA records of 500,000 animal species
Story by Alister Doyle, Environment Correspondent
REUTERS NEWS SERVICE
While this is an interesting area of research these are NOT new
species the in the way that the world understands and defines species.
These are attempts to re-define species by molecular differences in
populations AND an attempt to replace Linnean taxonomy with a "Barcode
of Life" taxonomy. I'm not making any value judgement here but it's
absurd to announce 15 new North American bird species without
explaining that this is labratory taxonomy done by people with DNA and
microscopes and computers...not field biologists that have found 15 new
birds that actually look different or act different from birds that
already exist and are recognized.
So indulge me some wild speculation...Using these criteria for
taxonomy you would probably find that each watershed in northern North
America had a DIFFERENT species of Brook Trout. Maybe a few thousand
different species. Because most populations of Brook trout have been
isolated for 15,000 years or so that could give them enough time to
diverge enough to be genetically distinct at the molecular level. So
who would it help if there were a 1,000 different species of Brook
So my questions is this: What do we gain by splitting hairs this
thinly? Is it useful to split Sedge Wrens and Curve-billed Thrashers
into two or three different species each? In the study of Butterflies
and Mushrooms we have started to hear more often this concept of
cryptic species....animals that look exactly alike but at the molecular
level may be different. Or they may be apparently identical
genetically but have some mechanism of behavior that prevents them from
interbreeding. Are they different species? And IF they are, what
does "different species" now mean?
Just some questions.....
The information contained within short segments of DNA within one
organelle of the nucleus of a single cell COULD be one tool that is
useful for determining that organism's relationship to an "outgroup"
and building a cladogram to illustrate that relationship. My point
is that it doesn't help anyone to say "ah-ha there's a new species"
if that's the ONLY character you use to delimit the "new" species.
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