In the 21st century, many advances have come from the scientific world that have benefited humanity as a whole. Possibly one of the most controversial of these has been genetically modified organisms, also known as GMOs. GMOs, are living organisms that have had genetic engineering done to their genome causing a change in expression, action, etc. These organisms, sometimes referred to as transgenic organisms have had the genetic material of another organism added to its genome using recombinant DNA technology. Near 30,000 BCE, long before our modern concept of genetically modified organisms existed, humans first produced domesticated dogs. Through artificial selection, desirable traits were chosen by humans, and these animals were allowed to breed together, reproducing increasingly more domesticated versions of the organism until they became what is conventionally known as “man’s best friend” today (1). This form of genetic manipulation is not directly corelated to GMOs that are seen now, but shows that even from an early existence, humans have set out to influence organisms to our benefit. One of the first genetically modified organisms, using genetic engineering, was seen when a new antibiotic resistance plasmid was constructed with in vitro endonuclease fragments joining and transferred into Escherichia coli in 1973 by Herbert Bower and Robert Helling (2). Before this, genetic engineering wasn’t even conceived of and this revolutionized how DNA was perceived, tested the boundaries of what could be genetically engineered, and showed the potential good it could be for humans.
Insulin, a hormone that is produced in the islets within the pancreas regulates blood glucose levels within the body. Those that cannot either produce insulin or metabolize insulin in the body suffer from diabetes mellitus. Diabetes mellitus leads to an increase of blood glucose levels, which overtime can lead to kidney damage, increased heart disease risk, eye damage, circulation issues, stroke, and even death. Diabetes mellitus was often almost a guaranteed early death, until 1922, when Frederick Banting and Charles Best injected pancreatic extract from a dog into a 14-year-old boy resulting in a mild decrease in blood glucose and upon further purification the injections gave lower glucosuria and blood glucose while ketonuria disappeared completely (3). Later, this led to the development of commercial animal insulin production mainly from pigs (porcine) and cows (bovine) and was extremely effective for controlling blood glucose in the majority of the diabetic population, however, overtime there were some issues that rose from animal insulin. As stated, the insulin has to be harvested from the animal, so samples from the pancreas have to be taken which overall is an expensive and time-consuming process. Animal insulin also needs to be purified to reduce the chance that those using it will develop a reaction to it which costs more money and still many had reactions to animal insulin. Finally, diabetes is a disease that continues to be on the rise. The World Health Organization reported that in 2014, 422 million people suffered from diabetes mellitus, an almost 4x increase from 108 million in 1980 (4). Production of animal insulin takes time and money to extract, purify, and prep, so an alternative needed to be produced. In 1978, only 5 years after the first GMO was introduced, a human insulin drug was being prepared by David Goeddel and his team and by 1982, Humulin was approved by the Food and Drug Administration (3). Humulin was the first genetically engineered drug for human use and was made by the recombinant DNA human insulin was put into Escherichia coli and human insulin was produced as the genetically modified Escherichia coli reproduced (3). The creation of GMO Escherichia coli that produce human insulin was revolutionary as it allowed for adequate amounts of insulin to be produced for the diabetic population, cheaper purification methods, and faster production methods helping to save what may now be potentially millions of lives that would’ve died without insulin. Genetically modified organisms extend out of the drug world and have recently been incorporated into the food industry too.
Human population has been a concerning issue for the past few centuries. Just within the past 50 years, the world population has more than doubled, showing a growth of just about 100 million people each year and just at the end of the 21st century, we could be looking at a population of over 11 billion people (5). The world population growth can largely be attributed to humans living longer and many still having children, and with this continually growing population comes to question of how to feed everyone. In many senses, standard farming practices seemed to be ineffective for much of the needs of the people, as well as costly with crop loss from insects, weeds, and short shelf life leading to food spoilage. In 1987, recombinant DNA technology started to be used on crops that could potentially provide better sources of food for our ever-growing population, and in 1994, the Food and Drug Administration approved the FLAVR SAVR tomato, a genetically modified tomato (1). The FLAVR SAVR tomato was produced by the genetic engineering to regulate polygalacturonase expression that is directly responsible for the ripening of the fruit, intern enhancing the flavor and extending the shelf life of the tomato (6). At first, many were skeptical about a fruit that had been modified in the lab, but the GMO tomato was eventually seen as a tastier alternative to a conventional tomato and so this opened the food world to genetic modification. Modification of many other crops ensued, making foods more visually appealing, having longer shelf lives, growing larger, etc. One of the most promising advancements in genetic engineering of food came from the development of golden rice. Hundreds of millions of people around the globe rely on rice as their major source of nutrition, however when consumed, only the endosperm is usually eaten containing only starch granules and lacking many essential nutrients for normal function (7). One of the key nutrients lacking from a rice diet is vitamin A, and in many countries around the world, millions suffer from a vitamin A deficiency which leads to xerophthalmia and eventually nyctalopia (night blindness), complete blindness, and even death in nearly 500,000 people worldwide each year (1). In 1999, Peter Beyer and associates found a biosynthetic pathway to genetically engineer -carotene (a precursor of vitamin A) to be produced within the endosperm of the rice by inserting a plant phytoene synthase and a bacterial phytoene desaturase (7). Although at first many were hesitant about golden rice mainly due to the color being different than what many are used to, it has slowly become more accepted around the world and could be arguably one of the most important GMO in the world today. Although GMOs have proven to be more effective in trying to support the world population and to help ailments like vitamin A deficiency, there are some major issues that come with the introduction of GMO crops into the ecosystem.
One of the biggest issues with the number of crops being produced as well as the cost of crop comes from crop loss. Crop loss typically comes from insects eating crops and weeds or other plants competing with crops for land and nutrients. Treatment of most crops with herbicides would often kill the crop themselves and although pesticides were used, many were ineffective so practices of controlling both the weed and insect populations were limited. Until in 1995, the first insecticide producing crop (corn) was approved by the Environmental Protection Agency as well as in 1996 the first herbicide resistant crop (soybean) was introduced (1). Herbicide resistance allows for more extensive herbicide usage while limiting the effect that it has on the crop itself, reducing competition created by other plants like weeds and boosting the crop growth. Whereas, insecticide production in crops was made possible from recombinant DNA technology used to insert crystal and cytolytic genes from Bacillus thurigiensis which produce insecticidal -endotoxins (8). Genetically engineered insecticide producing crops also known as Bt crops, cause cell membrane disruption within the insect’s midgut when -endotoxins are ingested as the toxins activated by proteases within the organism’s midgut ultimately leading to the death of the organism (8). Both of the development of insecticide producing, and herbicide resistant crops were huge developments as they lead to more stable growth and production of food sources, the expansion of agriculture to land that have been formerly unfarmed and decreasing the cost of crop production and the plants that we eat on a day to day basis. However, as these advances allowed higher crop yield, the integration of both pesticides and herbicides into our food and ecosystem have become some of the most controversial decisions in modern society.
As GMO crops have become larger in use, biodiversity has decreased significantly. Biodiversity is the variety of species present in an environment and in the case of crops, the species of crops that are being grown within an ecosystem as well as the overall culture of crops being available in markets. Producing Bt crops has led to a particularly profitable business of monocropping especially producing corn and soybeans. Monocropping has an enormous impact on the soil that the crops themselves grow on. A soil quality study conducted by Anna Bandick and Richard Dick, showed that soils with monocrops or crop rotation plots had significantly less enzyme activity when testing for nitrogen and other essential soil components then their grassy field or much more variable planting counterparts (9). Stripping nitrogen and other soil components reduces the effectiveness of the soil to actually grow crops or any other plants in the future on it, leading to crops facing more stress and becoming less quality. With monocropping and GMO crops, there is a huge environmental concern on their effects on pollinators like bees and butterflies. The production of monocropping methods as well as the reduction of weeds and other plants due to herbicides, has led to a less sustainable nectar supply for pollinators adding extreme stress to these organisms. However, although many individuals jump to the conclusion that pesticides that are produced hurt pollinators, these are typically specific enough to not affect pollinators at all. Overall, the actual overall effects of GMO crops on pollinators is still under debate. Once more, what comes into question is the actual use of pesticides and herbicides in GMOs. Just like bacteria develops antibiotic resistance, prolonged exposure to herbicides leads to the development of herbicide resistance in many species and the same for pesticides and many insect populations. In some countries, herbicides like glyphosate, the most common herbicide around the world, have had many species become resistant to their effects, in Australia alone, nearly 20 species (10). Not only have both herbicides and pesticides become less effective, but many of these have been questioned as to the effects on those that work with and/or consume them. Both the Environmental Protection Agency, EPA, and the World Health Organization, WHO, announced that again some of the most common herbicides and pesticides like glyphosate are probable carcinogens, showing the development of cancer in both mice and rats, and DNA damage and mutation in human cell tests (10). Much of these safety and environmental concerns have encouraged research to be done to find non-chemical forms of pest and weed control to reduce the environmental and consumption effects, but in many countries outside of the U.S., measures are already taken to prevent GMOs from even entering their ecosystems in the first place. Most countries outside the United States including, the majority of the European Union and Russia have completely banned GMO crops while countries like China, Japan, and Canada restrict GMO products not allowing for the use of herbicides and pesticide. Many of these countries prevent GMOs from ever being used because the long-term effects that they may have on the environment and those consuming these products are still unknown. Probably one of the most notable instances of the resistance against GMO crops was after the Haitian earthquake in 2010, one of the most devastating natural disasters to occur in the country. At the time, the Haitian government did not prohibit the use of GMO crops, and much of the country was in ruins with little to no crop yields, so after the devastating earthquake, Monsanto, the largest GMO crop producing company in the world, donated 60,000 seed sacks or 475 tons of seeds that were genetically engineered many of which containing pesticides and herbicides (11). In response, the country that was ravished by natural disaster and lack of food, committed to burning every seed that was donated making the claim that it was an assault on farmers, biodiversity, what was left of their environment, and their own seeds.
GMO crops have become an integral part of our farming industry within the United States. In my opinion there is both a good and a bad side to GMOs. Making alterations to crops increasing their nutritional content, yield, and shelf-life might be necessary changes that are needed to continue to feed an ever-growing population. The production of crops like golden rice are essential and have proven to help improve nourishment, health, and quality of life especially in the extremely poor in Third-World Countries. However, I also think there should be limitations to what we can alter. As it is right now, much of herbicidal and pesticidal use and effects on the environment and consumers are unknown, especially in the long-term. Many countries outside of the United States have put bans on the production and consumption of GMO crops until further understanding and research is done. Putting organisms that have some proven adverse effects on the environment and consumers and may be shown to have many more, directly into the market and environment can have considerable effects and unfortunately, we may not understand completely understand these until it’s too late. With the rise in herbicide resistance and pesticide resistance, we are facing huge issues already with the continued use, and so I think that making a change to increasing crop and biodiversity is ultimately the best method to continue sustainable crop growth with less of an ecological impact. However, increasing crop diversity to reduce pesticide and herbicide use until further understanding is placed is harder in practice as many farmers have become accustomed to GMO crop cycles, planting conditions, and this could lead to reduced profits for many farmers. There are many farms that have taken this step, as organic and non-GMO farming has been on the rise, attributing for a large portion of the food market now. Overall, genetically modified organisms are a very complex topic. Some like the development of human insulin, Humulin, and the production of golden rice have become lifesaving advancements. While others like the integration of monocropping, pesticides and herbicides have become extremely controversial and, in many countries, have been banned completely. Much more research is needed to be done on the environmental and population effects of both herbicidal and pesticidal components of GMO crops, but there is much that can be done as a consumer. Everyone has the decision as to what they put in their body, if GMO crops are off-putting then make a stand and purchase organic and non-GMO. We only have one planet, so we need to make sure that we can sustain our home and our population.