The current generation of genetically-modified organisms sometimes contains 'marker' genes. These are short, easily-detected sequences of DNA put there so that the researchers can tell which organisms have taken up the introduced genes. The Food Safety Unit of the World Health Organisation and a working party of the OECD has looked specifically at the safety issues associated with marker genes in plants that are to be consumed as foods. The marker genes in plant varieties approaching commercialisation are restricted to two markers that break down specific antibiotics and a few herbicide tolerance markers. However, the recent introduction and approval of maize with a bacterial marker conveying resistance to the antibiotic ampicillin has raised new fears, particularly in the European Union.
Biotechnology has the potential to affect world agriculture dramatically.
Although great benefits will probably come, many have suggested that there might also be accompanying disadvantages. Several of these disadvantages are no different to existing trends in world agriculture, such as the shift towards larger farms and more capital-intensive farming systems. This tends to favour, for example, wealthy farmers in the Northern hemisphere who can invest in new technologies rather than those in the impoverished South. In the developed world, there are concerns about over-production of food, although these worries are unlikely to be shared by those countries where the growth in population far outstrips the capacity of farmers to provide sufficient food. Biotechnology is probably the only technology which offers a realistic prospect of long-term sustainable agriculture to farmers in the Third World.