> John brings up an interesting point: just how reliable are all these new DNA tests at determine species, subspecies, etc.?<

Relying entirely on DNA provides greater opportunity to be totally,
wildly wrong due to contamination, a bad sample, etc.  There are
nematode and insect sequences in the database identified as molluscan,
for example.  I've gotten an insect sequence, a bacterial sequence,
and a trematode sequence myself when trying to amplify snail DNA.  The
trematode no doubt was parasitizing the snail, whereas the insect was
a booklouse, a tiny dot that eats paper and is common in the
collections building.  The bacterium was probably involved in decay,
since that specimen was a dead-collected endangered species.

There are also plenty of mixups and misidentifications for things
closer to the right name.

Some sort of actual sample is needed for the analyses.  This can be a
problem if it's not easy to poke the organism you want to identify
(What kind of cone shell is that?  Just pick it up and poke it with
your barcoder and see if its sting is fatal or not.), not to mention
the ease of getting bacteria or other things living on the organism
instead of the animal itself.

Although the gene may work well in cowries, it is giving strange
results with several other mollusks.  Pseudogenes (i.e., old copies of
the gene that have been incorporated into the genome somewhere, not
functioning as genes but available to be amplified in your analysis)
have been shown to be a serious problem in several crustaceans, and I
strongly suspect they're in the mollusk data already.

The biggest problem, however, is that there needs to be a thorough,
reliable data base to compare the sequences generated by the barcoder
to.  This won't happen unless there's support for people to work on it
and do it right-in conjunction with careful morphological work to
identify the species.  Try searching for jobs in invertebrate
systematics and you'll have an idea as to whether the necessary data
base will be in place in ten years.

--
Dr. David Campbell
425 Scientific Collections
University of Alabama
"I think of my happy condition, surrounded by acres of clams"

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