Genetic engineering is often used in combination with traditional breeding to produce the genetically engineered plant varieties on the market today.
For thousands of years, humans have been using traditional modification methods like selective breeding and cross-breeding to breed plants and animals with more desirable traits. For example, early farmers developed cross-breeding methods to grow corn with a range of colors, sizes, and uses. Today’s strawberries are a cross between a strawberry species native to North America and a strawberry species native to South America.
Most of the foods we eat today were created through traditional breeding methods. But changing plants and animals through traditional breeding can take a long time, and it is difficult to make very specific changes. After scientists developed genetic engineering in the 1970s, they were able to make similar changes in a more specific way and in a shorter amount of time.
A Timeline of Genetic Modification in Modern Agriculture
Circa 8000 BCE: Humans use traditional modification methods like selective breeding and cross-breeding to breed plants and animals with more desirable traits.
1866: Gregor Mendel, an Austrian monk, breeds two different types of peas and identifies the basic process of genetics.
1922: The first hybrid corn is produced and sold commercially.
1940: Plant breeders learn to use radiation or chemicals to randomly change an organism’s DNA.
1953: Building on the discoveries of chemist Rosalind Franklin, scientists James Watson and Francis Crick identify the structure of DNA.
1973: Biochemists Herbert Boyer and Stanley Cohen develop genetic engineering by inserting DNA from one bacteria into another.
1982: FDA approves the first consumer GMO product developed through genetic engineering: human insulin to treat diabetes.
1986: The federal government establishes the Coordinated Framework for the Regulation of Biotechnology. This policy describes how the U.S. Food and Drug Administration (FDA), U.S. Environmental Protection Agency (EPA), and U.S. Department of Agriculture (USDA) work together to regulate the safety of GMOs.
1992: FDA policy states that foods from GMO plants must meet the same requirements, including the same safety standards, as foods derived from traditionally bred plants.
1994: The first GMO produce created through genetic engineering—a GMO tomato—becomes available for sale after studies evaluated by federal agencies proved it to be as safe as traditionally bred tomatoes.
1990s: The first wave of GMO produce created through genetic engineering becomes available to consumers: summer squash, soybeans, cotton, corn, papayas, tomatoes, potatoes, and canola. Not all are still available for sale.
2003: The World Health Organization (WHO) and the Food and Agriculture Organization (FAO) of the United Nations develop international guidelines and standards to determine the safety of GMO foods.
2005: GMO alfalfa and sugar beets are available for sale in the United States.
2015: FDA approves an application for the first genetic modification in an animal for use as food, a genetically engineered salmon.
2016: Congress passes a law requiring labeling for some foods produced through genetic engineering and uses the term “bioengineered,” which will start to appear on some foods.
2017: GMO apples are available for sale in the U.S.
2019: FDA completes consultation on first food from a genome edited plant.
2020: GMO pink pineapple is available to U.S. consumers.
2020: Application for GalSafe pig was approved.
“GMO” (genetically modified organism) has become the common term consumers and popular media use to describe foods that have been created through genetic engineering. Genetic engineering is a process that involves:
The following example gives a general idea of the steps it takes to create a GMO plant. This example uses a type of insect-resistant corn called “Bt corn.” Keep in mind that the processes for creating a GMO plant, animal, or microorganism may be different.
To produce a GMO plant, scientists first identify what trait they want that plant to have, such as resistance to drought, herbicides, or insects. Then, they find an organism (plant, animal, or microorganism) that already has that trait within its genes. In this example, scientists wanted to create insect-resistant corn to reduce the need to spray pesticides. They identified a gene in a soil bacterium called Bacillus thuringiensis (Bt), which produces a natural insecticide that has been in use for many years in traditional and organic agriculture.
After scientists find the gene with the desired trait, they copy that gene.
For Bt corn, they copied the gene in Bt that would provide the insect-resistance trait.
Next, scientists use tools to insert the gene into the DNA of the plant. By inserting the Bt gene into the DNA of the corn plant, scientists gave it the insect resistance trait.
This new trait does not change the other existing traits.
In the laboratory, scientists grow the new corn plant to ensure it has adopted the desired trait (insect resistance). If successful, scientists first grow and monitor the new corn plant (now called Bt corn because it contains a gene from Bacillus thuringiensis) in greenhouses and then in small field tests before moving it into larger field tests. GMO plants go through in-depth review and tests before they are ready to be sold to farmers.
The entire process of bringing a GMO plant to the marketplace takes several years.
Scientists are developing new ways to create new varieties of crops and animals using a process called genome editing. These techniques can make changes more quickly and precisely than traditional breeding methods.
There are several genome editing tools, such as CRISPR. Scientists can use these newer genome editing tools to make crops more nutritious, drought tolerant, and resistant to insect pests and diseases.
