Genetic engineering

Work done by American geneticist Barbara McClintock showed that genes could jump between DNA strands. Biologists can now transfer genes from one organism to another. For example, genes that stop deep-water fish from freezing in the Antarctic can now be put into a tomato, to make it resistant to frost.

Opinions in favor of genetic engineering

Some people believe that modifying food crops to improve the vitamin content or make them resist drought or weedkillers will provide the world with more and better food.

Genetically engineered bacteria can produce human insulin for diabetics. Scientists hope they will be able to use it in the future to cure DNA errors that cause illnesses such as muscular dystrophy and cystic fibrosis. Cures are not yet imminent though.

Opinions against genetic engineering

Other people believe we know far too little about the consequences of altering plants in a way that is impossible in nature. They think it is too high a risk to let such plants loose in the environment where they might cross-breed with other plants and cannot be recalled if it is clear that the effects are harmful. There have been suggestions that one of the causes of the dramatic drop in the population of bees is the use in the USA of genetically-modified crops that are resistant to herbicides.

Many people are worried that if people are ever designed genetically, the human race could change in ways we cannot foresee. Most countries still have laws to prevent scientists researching genetic engineering in humans.