"Genetic modification (GM) is the alteration of the genome of a plant or animal by the addition of new genetic material. It underlies the concept of transgenics, in which an organism is modified to incorporate new genes that lead to new characteristics, such as the production of proteins for human health, or the expression of a gene for herbicide resistance in plants, to name just two applications.
GM is a contentious issue. Opponents believe that GM will damage the clean, green image of New Zealand as well as damage the economy, and there are numerous ethical issues to consider. What are the environmental risks of GM crops? Is it ethical to exploit animals for human benefit?
This article will provide an outline of GM, its uses in medicine and agriculture, and will help explain the issues surrounding the GM debate in New Zealand.
What is genetic modification?
GM provides a way of expressing desirable characteristics in an organism that otherwise would not display them. It is the insertion of a gene into an organism, altering the genetic makeup. This produces a transgenic organism, one that expresses a foreign gene. In animals, a gene is inserted into an embryo, modifying the genome to manufacture the product of this new gene. In plants, a gene is injected into a single cell that is grown from a seed into a plant. This plant expresses the new gene in all its cells.
The difference between GM and selective breeding.
Selective breeding is a form of genetic modification which doesn’t involve the addition of any foreign genetic material (DNA) into the organism. Rather, it is the conscious selection for desirable traits. Pro-GM campaigners argue that humans have been ‘genetically modifying’ organisms for thousands of years, albeit without knowledge that the favourable traits they were selecting for were determined by genes. For example, humans have always selected cows with the highest milk yield and bred from these to produce herds with good milk production. A chance mutant grape with no seeds was bred to produce seedless grapes now available in our shops and supermarkets."