GMO: What is a genetically modified organism?

A GMO is a plant, animal or microbe that carries extra genetic material, usually an extra gene built into the organism to give it new traits. Selective breeding of animals and plants does the same thing but in a slower and far less targeted way.

The ability to engineer an organism comes from our better understanding of the genetic blueprint, DNA, and how it works. Researchers identify a gene giving a useful characteristic in one organism and then transplant it into another organism so it too has this characteristic.

The new BT-11 sweetcorn product approved yesterday by the Commission is an example of this process. It looks and tastes just like ordinary sweetcorn but carries an extra gene taken from a bacterium, Bacillis thuringiensis. This gene produces a naturally occurring insecticide harmful to the highly destructive European corn borer. When the corn grows its leaves and kernels produce the insecticide, making them poisonous to the borer. The substance has no health effects on humans.

Resistance to herbicide damage has been built into soyabeans and sugar beets in the same way, allowing these crops to survive spraying to destroy weed growth.

The "FlavrSavr" tomato, an engineered variety with an extra gene that helps delay rotting, was the first GM food product to be released for human consumption. The Calgene company developed it in 1992 and the tomato went on sale after approval in 1994. The company has since gone out of business but modified tomatoes are still on the market.

Supporters of the technology argue that useful traits such as higher vitamin content can help solve nutritional diseases in developing countries. They claim using herbicide and insecticide-resistant crops would reduce the need for chemical sprays.

Opponents say that too little is known about this new technology and urge a precautionary approach to it. They argue there could be hidden health impacts and modified plants grown in the open could spread herbicide-resistant genes into weeds, making them impossible to clear.