Farmers have been genetically modifying plants and animals for thousands of years – producing hybrids through traditional breeding methods and then selecting out those with favourable characteristics. But these traditional methods, like cross-fertilisation, can take thousands of trials over many years to obtain the required characteristic and weed out undesirable ones.
Genetic engineering elimates the random element of traditional breeding by isolating and “splicing” the relevant genes.
Genetic engineering techniques have been used to produce
- medicines – the first being synthetic insulin approved in 1982;
- vaccines – beginning with a hepatitis B vaccine in 1987
- foods – the first whole product approved in the United States being vine-ripened tomatoes which could be shipped without rotting.
Genetic engineering techniques have been used on a small scale on humans to allow genetically infertile women to have children and to pass on their changed genome to their children. Techniques such as this, which treat a dysfunction are called “negative” genetic engineering. Such techniques have the potential to treat many disorders, such as spina bifida and cystic fibrosis and possibly forms of cancer, diabetes, autism and many other conditions. Theoretically, genetic engineering techniques could be used to allow people to grow limbs or damaged organs.
“Positive” genetic engineering seeks to make healthy people stronger, faster, smarter or longer lived. While this may be theoretically possible in the future, it does not currently seem to be any way that the technology could be developed without very unsafe and unethical human experimentation.