Other issues raised from the scientific literature reviewed in the
book Ecological Effects of Genetically Engineered Organisms:
3. Exotic, "introduced" species - of which GEO's will be just one
example - have a long and well documented history of becoming "pests"
in their new home. A recent issue of the journal Consequences
presented an authoritative review of just how often an introduced
species - whether it be plant, microbe, or animal - becomes pest-like
in a new environment (e.g. red deer in NZ; purple loosestrife in
Canada). In many respects, a pest could be defined as an organism
that is "out of context", out of range of the "controls" (e.g. its own
predators, pathogens, competitors) which regulated its density in its
zone of origin. It is not simply possible, but probable, that at
least some GEO's will behave as introduced species have already done
and become pests, with unimaginable outcomes.
The key point to note is that the introduced pests were not pests in
their zone of origin - they became pests in their new home. For
GEO's, the zone of origin could be considered the field test sites
which have already been used to authorize release. It is not
possible to predict how the GEO's will behave outside of those test
sites, just as it is not possible to predict how an introduced
species will behave outside of its zone of origin. And be clear as
well that this effect is different from and unrelated to the
implications of gene transfer from the transgenic crop to other
species. This effect accrues to the original GEO itself.
4. The method by which a researcher determines if s/he has been
successful in introducing new genes into a novel genome is to place
the new genes on a bit of DNA (or RNA, etc.), TOGETHER with a marker
gene, and then insert the bit of DNA into the new host DNA (my
apologies to those of you who would word this more scientifically,
but this is the sense of the process). The marker gene is most
often a gene conferring resistance to some common antibiotic. Then,
the researcher plates out the prospective new host cells on a medium
containing the antibiotic, and those that survive are those which
successfully integrated the new bit of DNA into their own DNA. Slick
and easy screen.
What this means in practice is that every time you bite into a Flavr
Savor tomato (if you somehow know it is a Flavr Savor tomato,
because the company owning this product was successful in
preventing labelling of this GE tomato to allow consumers to make
an informed choice), you are ingesting genes for antibiotic
resistance. For some years, proponents of these products have said
that this was not a problem, because the genes would be digested in
the stomach - end of story. Newer evidence, published I believe in
Nature or Science within the last year, found otherwise. Just as
we scientists can excise out and reinsert little bits of DNA (RNA,
etc.) to make transgenic plants, so too the bits of DNA can be
subsequently released and reinserted into new, unintentional host
cells - like an E. coli cell in your child's stomach. The risk is
small - granted - but not negligible.
Do the benefits of FlavrSavor genes (or BST-stimulated milk in cows,
or Bt corn, or.......) outweigh the implications of distributing
antibiotic resistance genes not simply into our own digestive tracts
but into the the whole agroecosystem?
5. Are the products of genetic engineering actually needed in the
first place, and what are their implications for the environment and
society as a whole? Some 90% of the transgenic crop research underway
in Canada involves identifying and inserting herbicide resistance
genes into crop plants. Is there any reason to think that the same,
long known and very well documented pattern of resistance development
in target organisms (e.g. DDT and gnats in CA; Colorado potato
beetles and everything, everywhere; triazine resistance in major
weeds, etc.) will NOT happen - and faster - when the genes for
resistance are actually present in the crop plants themselves? The
selection pressure exerted by the presence of resistance genes in
hundreds of thousands of hectares of a given crop would be enormous.
Who is the net beneficiary of this line of thinking? Producers?
Consumers? The environment? Who?
In sum, the foregoing is meant to provide evidence -
hard scientific evidence of the sort published in respected, peer
reviewed journals, not fabricated by wild-eyed misguided activists
whipping up hysteria in an ill-informed consuming public (this is how
the argument is usually framed)
- to challenge the thesis that biotechnology is a valuable tool in
the genetic improvement of crops and livestock.
Indeed, the converse seems much more likely. It seems not
implausible to me that people will soon look back and wonder at the
ecological naivete and unfettered optimism that allowed biotechnology
to rise to prominence in this era of agricultural research. Ann
ACLARK@crop.uoguelph.ca
Dr. E. Ann Clark
Associate Professor
Crop Science
University of Guelph
Guelph, ON N1G 2W1
Phone: 519-824-4120 Ext. 2508
FAX: 519 763-8933