By James Borrell
PhD Researcher in Conservation Genetics, Queen Mary University of London
April 4, 2016, 9:47 AM EDT
Introduction
Genetically Modified Organisms (GMOs) have been the subject of intense debate for decades. This article highlights fundamental concepts in GMOs and dispels ill-founded misconceptions. With changing soil conditions and humanity's food security system at stake, understanding the spectrum of genetic manipulation is crucial.
All Our Food Is ‘Genetically Modified’ in Some Way – Where Do You Draw the Line?
In the past week, you’ve likely eaten crops that wouldn’t exist in nature or have evolved extra genes to reach freakish sizes. You’ve probably consumed “cloned” food and even plants whose ancestors were deliberately blasted with radiation. Surprisingly, you could have bought all this in the “organic” section of your local supermarket.
Anti-GM dogma often obscures the real debate over what level of genetic manipulation society deems acceptable. GM technology is not a binary decision—either for or against—with no middle ground. Blanket bans, like those in many European countries, stifle debate. After all, very little of our food is truly “natural,” and even basic crops result from human manipulation.
Between organic foods and tobacco engineered to glow in the dark lies a broad spectrum of modifications worthy of consideration. Often lumped together under “GM,” these technologies vary widely. Where would you draw the line?
1. (Un)natural Selection
Consider carrots, corn, or watermelons—foods you eat without much thought. Compared to their wild ancestors, even “organic” varieties are almost unrecognizable. Domestication involves selecting for beneficial traits like high yield. Over generations, human-made selection can substantially alter a plant’s genetic makeup, producing forms extremely unlikely to occur in nature.
2. Genome Duplications
Our ancestors unknowingly triggered a genetic process we only recently discovered. Humans inherit half a set of chromosomes from each parent, but some organisms, especially plants, can have two or more complete duplicate sets—known as polyploidy. This often results in exaggerated traits like larger fruit, likely due to multiple gene copies. Without realizing it, crops like ginger (triploid), apples (triploid), potatoes (tetraploid), and cabbage (tetraploid) were bred to higher ploidy levels naturally, as large fruit or vigorous growth were desirable. Some strawberry varieties are even octoploid, with eight sets of chromosomes compared to humans’ two.
3. Plant Cloning
The word “cloning” conjures discomfort, yet no one balks at eating cloned food. Asexual reproduction is common in nature, and farmers have used it for centuries to perfect crops. Once a plant with desirable traits—like a tasty, durable banana—is found, cloning produces identical replicates. This can be natural (via cuttings or runners) or induced with plant hormones. Domestic bananas, lacking seeds, are clones of previous generations.
4. Induced Mutations
Selection—human or natural—relies on genetic variation within a species. If a trait never occurs, it can’t be selected. To generate variation, scientists in the 1920s began exposing seeds to chemicals or radiation. This “mutational breeding” is untargeted, creating random mutations—most useless, some desirable. Over 1,800 cultivars of crops and ornamental plants, including wheat, rice, cotton, and peanuts, have been developed and released in over 50 countries. This approach spurred the 20th-century “green revolution.” Red grapefruits and some pasta wheat varieties, still sold as “organic,” result from this method.
5. GM Screening
GM technology doesn’t always involve direct manipulation. It can screen for traits like disease susceptibility or identify the best natural crosses for yield. For example, genetic technology helps identify ash trees resistant to ash dieback disease, enabling future forests to be grown from these. This “genomics-informed” human selection enhances breeding without altering genes directly.
6. Cisgenic and Transgenic
This is what most people mean by GMOs—genes artificially inserted into a plant to improve yield, heat or drought tolerance, produce better drugs, or add vitamins. Conventional breeding might take decades; added genes offer a shortcut.
• Cisgenic: Genes are inserted, moved, or duplicated from the same or closely related species.
•Transgenic: Genes from an unrelated species are inserted, a technique producing organisms unlikely in nature. Since the 1990s, crops like “Bt corn” have been engineered with a gene from Bacillus thuringiensis bacteria, offering pest resistance as an alternative to pesticides.
Transgenic tech is controversial, with concerns about resistance genes “escaping” to other species or being unfit for consumption. Though unlikely—fail-safes prevent this—the possibility exists.
Where Do You Stand?
All these methods are in use. Transgenic crops have been widely cultivated for over a decade, closely scrutinized, and rightly so. With the global population set to hit nine billion by 2050 and increasing environmental strain, GMOs offer potential to improve health, boost yields, and reduce impact. However uncomfortable they may feel, they deserve a sensible, informed debate.
Disclosure Statement James Borrell is currently a NERC-funded PhD student.
Original Publication This article was originally published in The Conversation: https://theconversation.com/all-our-food-is-genetically-modified-in-some-way-where-do-you-draw-the-line-56256