August 8, 2024

Lily Sharkey

12th Grade

Dominican Academy

Everyone tells you to avoid them, but what are they? A genetically modified organism (GMO) is a plant, animal, or microbe whose traits have been modified to achieve a purpose; this is done through genetically engineering the genome, either introducing, multiplying, or deleting genes in a sequence. Although the genetic engineering required to edit organisms is very modern, humans have been utilizing a process to manipulate organisms for thousands of years. Cross-breeding or selective breeding plants and animals to produce the most desirable traits are examples of early genetic modification; in some ways, purebred dogs are GMOs.

GMOs were introduced in 1973 by biochemists Herbert Boyer and Stanley Cohen, who transplanted the DNA of one bacterium into another. Not ten years later, the Food and Drug Administration (FDA) approved the first GMO product: human insulin to treat diabetes produced by bacteria. Since then, GMOs have been widely used in the agriculture industry, among others, to increase the nutritional content of food and pest resistance of crops. The objective of using GMOs in agriculture is to produce more cost-effective food. According to the FDA, GMO foods are as “healthful and safe” as non-GMO foods. Data from the National Academies of Sciences, Engineering, and Medicine tracked levels of cancer in the United States and Europe; the data shows that changes in patterns of cancer rates in both regions are similar. As GMO foods are eaten less in Europe compared to the United States, the FDA concludes that changes in cancer rates are not connected to the consumption of GMOs. Furthermore, allergenicity testing is a major part of all GMO production; these tests allow scientists to know exactly what proteins have been produced in GMOs and ensure they are not allergens. For this reason, GMOs are not, as presumed, the reason for rising cases of celiac disease, an allergen condition caused by abnormal digestive response to gluten, a protein found in wheat, rye, and barley. There is no GMO wheat, rye, or barley available on the market in the United States. Cornstarch, corn syrup, corn oil, soybean oil, canola oil, or granulated sugar are examples of popular ingredients made with GMO crops available in the United States. 

The most common GMO crop in the United States is corn. Bacillus thuringiensis (Bt) corn is a GMO corn that creates proteins toxic to certain insects but not to humans or animals. Bt corn negates the need for spraying harmful pesticides that can pollute water supplies while protecting the crop from harmful pests; beneficial insects such as ladybugs are not harmed by these proteins. Much of this GMO corn is used in processed food and drinks but most of it is used as meal for livestock and poultry. Studies show that there is no difference in the nutrition or health of animals who eat GMO food versus those who eat non-GMO food. Additionally, the DNA of the GMO does not transfer to the organism eating it, so the meat and dairy products produced by these animals are not inherently GMO; regardless, the products are safe for humans to consume. Soybean, cotton, papaya, potato, and apple are other examples of popular genetically modified crops. Alternatives to GMO products include non-GMO and organic products; non-GMO means the food was not produced with genetically modified ingredients while organic means it does not contain pesticides, GMOs, or other chemical and drug residues. In order for a product to be organic, it can only include up to 5% non-organic ingredients; this excludes GMOs except in rare cases where there is no non-GMO alternative. Organic farmers cannot plant GMO seeds, organic livestock cannot consume GMO feed, and organic producers cannot use GMO ingredients.

GMOs are typically created using recombinant DNA technology (rDNA). rDNA is a form of gene editing in which enzymes are used to isolate and separate pieces of DNA from a sequence and splice them into a different sequence. The result is a new gene with a different function. Many methods of genetic engineering use rDNA to manipulate the genome, one such being microbial vectors. Agrobacterium tumefaciens is a soil microbe that causes crown gall disease in certain plant species. It causes an abnormal growth of plant tissue cells on the roots and lower stems, known as galls. When this pathogen infects a host, it transmits some of its DNA into the plant cell; the DNA is then integrated into the plant which produces substances to spur the growth of the plant’s gall into a disfigured gall. Agrobacterium without the crown gall-causing DNA was discovered in the early 1980s and allowed scientists to insert other DNA into the genome. The natural genetic engineer then operates as usual, injecting an infected plant with the intended DNA as orchestrated by the scientist. If the infected cell grows into a mature plant, all of the plant offspring will also carry the desired genes. There are other ways to genetically modify crops but this method is used for most genetically engineered crops in production.

But is anything truly GMO-free? Studies say that 1 in 20 flowering plants are naturally transgenic, meaning unrelated DNA has been introduced into the genome; sweet potatoes were also discovered to be transgenic. Bananas, peanuts, Surinam cherries, hops, cranberries, and tea contain Agrobacterium, meaning they have been naturally genetically modified in some way. Grafting plants can lead to DNA transfer, a practice done by humans for thousands of years. 

GMOs in the wild can impact genetic diversity by overtaking a population or crossbreeding with wild organisms. Hybridization is the ability of two species to mate. If a non-GMO and GMO species were to hybridize, there are concerns that the modified gene would have an advantage in the hybrid, thereby maintaining the modified gene in the species and decreasing genetic diversity. While there is still little evidence of the negative effect of GMOs on genetic diversity, scientists are aware of the possible impact of GMOs on biodiversity.

For millennia, humans have been manipulating nature to achieve the most desirable effects; from plants to animals, early forms of genetic modification have existed nearly as long as humans. The 1970s discovery of microbes that have been naturally editing the genome has paved the way for the modern conception of genetically modified organisms. The use of GMOs has many benefits, from manufacturing medication to making agriculture production more cost-effective and protecting the environment. With all of these groundbreaking discoveries, scientists must also exercise caution when considering the effects of GMOs on natural wildlife.