When I have read about genetically modified (GM) plants I have been under the misconception that these were simply plants given a boost to speed up growth and increase crop production. I then filed the thought of GM crops under a label of …’there must be a catch’. I didn’t really think through what was actually being offered.
The more sceptical amongst us worry more about the details of GM food;
Potential threats to human health from consuming food from GM crops
Possibilities that GM crops could have adverse environmental effects including the risk that some might become invasive weeds
Contamination of non-GM by genes carried in pollen or seeds
One area that I have never understood is the confusion in where the risk lies? Is it in the GM technology itself or from the genes that the technology has been used to transfer?
Supporters of the GM debate tend to argue that the methods used are simply a better way of achieving what plant breeders have been doing for millennia – and just speeding up what has naturally happened in nature throughout the history of life.
At a conference in Atlanta Toby Bradshaw a plant biotechnologist stated … ‘it’s a myth to think that humans invented the transfer of genes into plants. It has been done for millions and millions of years by soil bacteria, and it is possible to convince those bacteria to transfer any bit of DNA that you would like moved into a plant.’ Earlier in the year a group calling itself the ‘Earth Liberation Front’ had burned Bradshaw’s lab to the ground citing the fact that his work … ‘unleashes mutant genes into the environment…’
However the genes that the scientists trick the soil bacteria into transferring are not the genes that these bacteria naturally transfer – even if the process is natural, the product is not.
Proponents of GM focus on the safety of the tools for the gene transfer – and tend to consider that the problems are only associated with particular genes – ie it’s not the GM tool – but what you do with it that matters. Those against GM ignore this distinction taking the stance that exotic genes couldn’t be transferred and become a problem without the GM technology.
Conventional plant breeding can produce odd products – but these hazards receive no attention because they never get to the market place.
One of the earliest ‘rumours’ around GM crops was the suspicion that they had a resistance to antibiotics. The gene was there as a by-product of the genetic engineering process – not because it served any useful function. The idea persisted that the GM food might contain something that might inactivate antibiotics – and the fear that this could spread from GM crops caused understandable alarm.
Current fears concern genes for herbicide tolerance and a gene that produces a toxin that kills caterpillars. Obviously farmers are in a continual battle against weeds and insect pests – any advantageous method that reduces damage done by these two scourges would help them…if…they can still sell the crop. The ‘if’ is crucial – if consumers are suspicious of GM crops then supermarket chains and food producers will simply refuse to buy the crops.
From the farmer’s viewpoint, a perfect herbicide is one that will kill problem weeds without doing any damage to the crop. The big herbicide manufacturers like Monsanto have produced GM crop varieties that are tolerant of their proprietary brand herbicides – thus by sowing these GM seeds and applying the proprietary herbicide… a farmer can in theory grow a weed free crop.
But what happens if these plants cross pollinate with other species producing plants that are tolerant of herbicides ….
No competent plant scientist would ever claim to be ignorant of the possibilities when adjacent herbicide tolerant plants that are insect pollinated are put into the general cycle of food production. Herbicide tolerance could well spread form these fields into the wild causing irreversible harm …
Imagine a herbicide tolerant, fertile Japanese Knotweed plant and you have a major issue on your hands …with very few weapons to tackle it with.
Ref: ‘Demons in Eden’ Jonathon Silverman