The herbicide resistance of a GM crop will be transferred to a weed. Insects become resistant to the pesticides produced by crops that have been genetically modified to produce their own pesticides. These crops may harm beneficial insects and the intended crop-damaging pests. For example, In the United States, glyphosate-tolerant weeds are plaguing GM cotton and soya fields, and atrazine, one of the most toxic herbicides, has had to be used with glufosinate-tolerant GM maize. Bt biopesticide traits are simultaneously threatening to create superweeds and Bt- resistant pests.
Unavoidable Extensive transgenic contamination:
GM crops have caused transgenic contamination that caused major crop failure which led to loss in sales for farmers and within the agric industry. New research shows that transgenic pollen, wind-blown and deposited elsewhere, or fallen directly to the ground, is a major source of transgenic contamination. Contamination is generally acknowledged to be unavoidable. Extensive transgenic contamination has occurred in maize landraces growing in remote regions in Mexico despite an official moratorium that has been in place since 1998. High levels of contamination have since been found in Canada. In a test of 33 certified seed stocks, 32 were found contaminated.
Introduction of antibiotic-resistant gene or tracer into genetic material of plant may cause gene transfer to non-target species:
Scientist often introduce antibiotic-resistant gene (or tracer) into the genetic material that is being introduced into a plant to see if the modified cell is able to survive antibiotic treatment, meaning it’s become resistant to that antibiotic and has probably taken on other characteristic carried in the newly added genetic material. Antibiotic-resistant tracers can be transferred to a disease-causing microorganism.
Impacts of GM crops have on the Environment?
“Last year, 71 percent of all GM crops grown were genetically engineered to be herbicide resistant. A field can now be sprayed with chemicals and everything will die except for the resistant crop. Graham Wynne, Chief Executive of the Royal Society for the Protection of Birds, says: "The ability to clear fields of all weeds using powerful herbicides which can be sprayed onto GM herbicide-resistant crops will result in farmlands devoid of wildlife and will spell disaster for millions of already declining birds and plants."
There are also GM virus-resistant crops. Prof Joe Cummins says: "Probably the greatest threat from genetically altered crops is the insertion of modified virus and insect virus genes into crops - genetic recombination will create virulent new viruses from such constructions. The widely used cauliflower mosaic virus (present in the GM soy and maize currently on supermarket shelves in the UK) is a potentially dangerous gene. It is very similar to the Hepatitis B virus and related to HIV. Modified viruses could cause famine by destroying crops or cause human and animal disease epidemic".
Also, Glufosinate ammonium and glyphosate are used with the herbicide-tolerant transgenic crops inhibits beneficial soil bacteria and fungi, especially those that fix nitrogen back into soil.
Breeding resistance:
Nature is smart, and there are already reports of species resistant to GM crops emerging. This is seen in the emergence of new ‘super-weeds’ on farms in North America – plants that has evolved with the ability to withstand the industry’s chemicals. A report by the UK conservation body English Nature (now Natural England), in 2002, revealed that oilseed rape plants that had become resistance to three or more herbicides were ‘not uncommon’ in Canada. The super-weeds had been created through random crosses between neighboring GM crops. In order to tackle these super-weeds, Canadian farmers were forced to resort to even stronger, more toxic herbicides—that also holds a potential toxic effect on the health of consumers. Similarly, pests (notably the diamondback moth) have been quick to develop resistance to BT toxin, and in 2007 swarms of mealy bugs began attacking supposedly pest resistant Indian cotton.
In India, farmers’ experience of BT cotton has been so disastrous that the
Maharashtra government now advises that farmers grow soybeans instead.
Genetic engineering creates super-viruses:
By far the most insidious dangers of genetic engineering are inherent to the process itself, which greatly enhances the scope and probability of horizontal gene transfer and recombination, the main route to creating viruses and bacteria that cause disease epidemics. This was highlighted, in 2001, by the 'accidental' creation of a killer mouse virus in the course of an apparently innocent genetic engineering experiment.
Newer techniques, such as DNA shuffling are allowing geneticists to create in a matter of minutes in the laboratory millions of recombinant viruses that have never existed in billions of years of evolution. Disease-causing viruses and bacteria and their genetic material are the predominant materials and tools for genetic engineering, as much as for the intentional creation of bio-weapons—(use of food as a weapon at war).
A history of misrepresentation and suppression of scientific evidence:
There has been a history of misrepresentation and suppression of scientific evidence, especially on horizontal gene transfer. Key experiments failed to be performed, or were performed badly and then misrepresented. Many experiments were not followed up, including investigations on whether the CaMV 35S promoter is responsible for the 'growth-factor-like' effects observed in young rats fed GM potatoes.
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