What is a genetically modified organism, or GMO?
Even the answer to the question can be controversial.
At its most basic, genetic modification is the process by which changes occur in an organism’s genome. Nature is perpetually modifying the genetics of every organism in an effort to help the organism adapt to its changing environment.
“It’s important to understand that all organisms — not just those that are the basis of foods — are genetically modified in some way, shape or form,” says Brad Day, a professor and associate department chair for research in Michigan State University’s Department of Plant, Soil and Microbial Sciences. “They are genetically modified by persisting in the environment. Radiation from the sun can induce changes in the genome, for example.”
The origins of GMOs
More than 30,000 years ago, humans realized they could have a hand in the process of modifying genes when they domesticated and began selectively breeding wolves to ensure the animals passed along specific characteristics. Humans also have bred plants for thousands of years in an effort to ensure the survival of desirable traits.While conventional selective breeding methods are still the most common, the newer biotechnology techniques used to create GMOs are actually rooted in genetic engineering. Scientists use biotechnology to insert one or more genes from one organism into another to give the second organism the specific trait controlled by the transferred gene or genes.
Adding a gene that promotes drought resistance, for instance, may permit farmers to grow a crop in a nontraditional region of the world or in an area with dwindling water resources.
In 1973, scientists Herbert Boyer and Stanley Cohen created the first genetically engineered organism — E. coli bacteria that had the gene for resistance to the antibiotic tetracycline transferred into it. Once the pair demonstrated that the organisms could pass the added trait to subsequent generations, interest in genetic engineering ballooned.
Farmers who became early adopters of genetically modified crops did so primarily to save money. Insect-resistant crops needed fewer pesticide applications, and herbicide-resistant crops made weed control easier and more effective.
“Genetic engineering is a technology used in several disciplines, but food has been by far the most controversial [use],” says Day. “Changes in the genome may include input traits — something that helps the grower manage the crop better in response to insects, diseases or weeds. There are also output traits — things that might improve yield, delay flowering times or enhance a plant’s ability to produce a nutritional element such as a vitamin.”