- A marker gene is added because genetic modification is a haphazard process and the scientist needs to know where the gene hasarrived in the host genome. Until recently antibiotic-resistance marker genes were usually used. It has now been found that these genes can be taken up by bacteria in the gut. The British Medical Association says that the use of such genes is 'completely unacceptable.'
- Random extra genes get transferred. These are not planned, but strands of unexpected DNA have been found, e.g. in Monsanto soybeans. This DNA may be unstable.
These are some of the ways in which genetic engineering alters plants. Can this really be described as similar to conventional breeding techniques? The biotech industry, with strange logic, claims that genetic engineering is no different from normal plant breeding yet also claims it is a radically new science. US agencies define GM food as 'substantially equivalent' to ordinary food, so consumers are denied labelling.
But Europe was worried that independent testing of GM foods had not been carried out and it imposed a five-year ban on growing GM crops. European regulations have cost US farmers $12 billion in lost trade. European concern has now spread back to the US.
Allergies are a major problem. The National Academy of Sciences, the top US scientific body, warns that genetically engineered plants may introduce allergens into pollen, which then spreads them in the environment.
