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| Darwin's theory of evolution suggest nature selects for genetic adaptations that will increase a species' fitness for survival. This selection process has no pre-designed plan to benefit one species over another. The science of genetic engineering is placing that selection process in human hands. Scientists are currently genetically modifying agricultural plants to increases their productivity. They believe this new technology will help solve world hunger issues. At the same time, antibiotic resistance is increasing in the bacteria of infectious diseases through the misuse of antibiotics both with livestock and humans. Genetic engineers are experimenting with the same technology they use to alter plant genes, in search of genetic approaches for treating infectious diseases and in the future the potential to reduce or eliminate genetic defects in humans. When or if that goal is achieved, genetic enhancements to humans may become possible. The irreversible long term consequences of this technology, for all living organisms, will not be known until several generations down the evolutionary path; proceeding with caution is warranted. | |
| 1 | In 1859, Darwin proposed the concept of evolution by natural selection in his then controversial theory, "The Origins of Species." This theory proposed species evolve through a series of outward and inward physical traits that nature selects for based on the trait's adaptive characteristics which will increase the living organism's chance of survival and ability to produce viable offspring, which also demonstrate the adaptive characteristic. He called these inheritable traits an organism's fitness. Those organisms which are more genetically fit at adapting to their environment and producing viable offspring increase the chances of their species' survival over those less adaptive, in the same species and sometimes other species, to their environment. Humans have been aggressively studying and attempting to alter, sometimes successfully, this process in their own species, as well as in plant species, other animals and micro-biological organisms. The long term consequences to the environment and all living organisms brought about by attempts to alter the process of natural selection have not yet been determined. However, the genetically engineered modifications of plant species, the misuse of life-saving antibiotics, and the even more questionable research involving genetic alterations in humans are raising questions concerning the immediate and long term affects both to the environment and living organisms. If humans continue to play with the process of natural selection the consequences to their own species and the environment will create irreversible affects. |
| 2 | Altering the genetic make-up of agricultural crops to produce healthier and hardier plants appears to be less threatening on the surface then altering genetic traits in humans. However, the path from point A leads directly to point B. First, agriculture plants are altered which coincides with altering agricultural animals by the use of antibiotics to enhance their growth. Although this is not the sole cause of resistance, as more antibiotics are introduced into the human environment bacteria begin to evolve, becoming more resistant to antibiotics. Antibiotic-resistant diseases begin to invade human hosts more frequently. Scientists then begin to look for genetic alterations in humans to combat diseases using similar, if not the same, techniques used to alter agricultural products. The trial and error process of this chain of events leads to some known and many unknown irreversible consequences to the environment and living organisms of all sizes; plus the potential of affecting the overall adaptive fitness of a species and its viable offspring. |
| 3 | The first step on the path from point A to point B to be examined in more detail is the genetic engineering of agricultural crops. Humans have been trying to control nature since the beginning of time. All agriculturally grown crops were wild plants at one time. Humans have selectively bred and developed plants over thousands of years to produce what today are called agriculture products. A trial and error process called hybridization is used over several generations of plants' lives to produce plants with common traits. In the hybridization process, unwanted genetic traits come along with the wanted traits. As the new millenium begins, transgenetic engineering technology of agriculture products has increased the ability to further alter their evolutionary process. Transgenetic engineering allows scientists to take a specific gene or DNA strands from one plant type or even a different species and insert them into the genes of the plant type they want to alter. The result is a plant type with a specific genetic trait or traits it would not have normally demonstrated. This new technology has raised many questions and concerns, both in the scientific community and among the general population. In the Journal of Soil and Water Conservation, Maureen Kuwano Hinkle, who has worked on pesticides issues for the Environmental Defense Fund and more recently agricultural policy program for the National Audubon Society, sums up the crux of the issues with this statement: "The focus has been too much on the technology and a race for what it CAN do; not what needs to be done for feeding the poor, safety, the environment, sustainability and biodiversity." |
| 4 | In 1983, the production of the first genetically engineered plant was reported; by 1999, half of all soybeans planted and 25 percent of corn crops grown in the United States had been genetically engineered (Hinkle). Some of the other plants that have been field tested and in some cases approved for limited use include tomato, cotton, tobacco, rapeseed (canola), potato, carrot, squash, melon, alfalfa, turf grass, strawberry, apple, plum, papaya, walnut, poplar, and spruce (Snow). The four most common altered traits connected to the economic production of agricultural products are herbicide tolerance, insect resistance, disease resistance, and environmental stress tolerance. However, the technology itself is not what is being called into question. The potential effects to the environment and all living organisms of these four traits and the potential for large seed companies, who can afford the overhead for experimental technology, to gain a complete monopoly of the seed supply are the main topics being debated regarding this technology. |
| 5 | Genetically altered plants that are engineered to be herbicide tolerant make those plants more resistant to the effects of herbicides. In their article "GM Plants: Concepts and Issues" for the Journal of Biological Education, Robert Marchant, a researcher in the Plant Science Division of the School of Biological Science, University of Nottingham, and Elizabeth Marchant, a tutor in the School of Continuing Education at the same university, assert that "In 1998, seventy one percent of genetically modified crop acreage (49.5 million acres world-wide) consisted of herbicide tolerant crops, . . . ." This trait enables the agriculture industry to spray crops with toxic chemicals that have little or no effect on the crops in order to control unwanted weeds. Not having to control weeds by other means creates a cut in the cost of producing agricultural products, which in turn can be passed on to consumers. |
| 6 | The first concern in respect to herbicide tolerant crops is the potential for weeds to genetically evolve to the point of being chemically tolerant themselves by natural means from long term exposure. Genetically engineered crops have also been know to cross-pollinate with wild cousins, creating herbicide-tolerant weeds. If left uncontrolled by other means, these "superweeds" could invade and destroy natural habitats. |
| 7 | The second issue concerning herbicide tolerant crops has to do with economics. Most crops are currently being altered for a tolerance to glyphosate, the active ingredient in the Roundup Trademark (Marchant). This gives the Roundup manufacturers an unfair advantage in the treatment of these crops. Promotion of crops specifically altered to tolerate one type of chemical could also lead to an overabundance of that chemical being released into the environment. What impact this would have on the environment and all living organisms is unknown. |
| 8 | The next transgenic engineering technology applied to agriculture products consist of plants that are modified to be insect repellant. This is done by introducing a biological toxin, usually BT (Bacillus thuringiensis) bacterium, into the genes of plants, creating plants that manufacture their own pesticides in every cell. The agricultural benefit of this technology impacts both the environment and economics. Natural pesticides versus chemically-produced pesticides are released into the environment and growers are able to cut cost by not having to purchase the expensive, commercially-produced, chemical pesticides. Because the pesticides are in the plant cells and are not washed off during the cleaning process, the crops are also more pest resistant once they are harvested and stored (Snow). The agricultural industry also hopes this technology will increase crop yields, which in turn could help alleviate world hunger problems. |
| 9 | BT is considered a natural pesticide and is popular in moderation with organic farmers. The over use of this pesticide, cry the organic farmers, will render it useless by creating "superbugs" that evolve to become BT resistant. "Even the industry's own scientists concede that it is just a matter of time - as little as 3 to 5 years- before BT-resistant insect strains evolve," claim John Grogan and Cheryl Long in Organic Gardening. There is another potential adverse effect that comes along with the evolution of the ability to repel insects: The insects with a naturally stronger resistance factor to the pesticide will more than likely be the specimens to survive. If they were to cross-breed with other cousin insects, which has been known to happen, this cousin type could also become resistant creating a larger variety of pesticide resistant insects (Snow). |
| 10 | Other potential problems include targeted insects preying on alternative plant varieties, where they are not considered to be a problem as of yet; reduced competition with insects that are already naturally resistant; and the possible mass reduction or even extinction of insects that are fodder for other forms of wildlife such as birds, snakes, spiders and lizards. Because the pesticides reside in all cells of the plant, including the root systems, there could be a negative ecological impact to the microbiological organisms in the soil as well (Snow). |
| 11 | Grogan and Long sum up the human risk element of this controversial technology with this analogue ". . . although there is no evidence that BT-carrying crops hurt humans, there is something unsettling about eating food that is itself a pesticide registered with the EPA. Unlike conventional pesticides, the built-in BT bug killer cannot be washed off; it is in every bite." |
| 12 | Another genetically engineered trait in plants, disease-resistance, may be adding to potential life-threatening consequences in humans. Due to overuse, all living organisms are becoming less susceptible to the positive effects of antibiotics in the treatment of diseases. Agriculture products genetically engineered with disease resistant biological cells compounds this evolutionary process by increasing antibiotic cells in the human diet, through altered plant cells that cannot be washed off. Traditionally, antibiotic sprays have been used to control crop diseases. The Agriculture industry asserts the use of genetically modified disease-resistant genes in plants produces higher yielding, healthier crops with less environmental impact than traditional methods, because the antibiotics are contained in the cells of the plants and not released into the entire environment. To minimize the risk of antibiotic ineffectiveness, all the parties involved agree the use of antibiotics used to treat human ailments should be banned or limited (Marchant). |
| 13 | This genetic trait-altering technology brings into view a new controversy, cross-kingdom transfers. Some examples of this would include the transference of a chicken gene into apples and giant silk moth genes into tobacco, potatoes and apples to reduce bacterial infections. Because certain domesticated animal genes and diseases have been studied for longer periods of time, cross-kingdom approaches create quicker and more consistent results when attempting to eliminate crop diseases (Snow). The concerns surrounding this process are generally moral or religious issues more than health concerns or scientific issues. For instance, people who choose not to eat meat products for religious or moral reasons could now do so without knowing it, since products containing genetically modified foods are currently not required to disclose this fact on their labels (Grogan 46). There is also an associated health risk for people with known allergies or potential unknown allergic reactions when genetic material from kingdoms not normally consumed are introduced. A well-known example of this type of reaction in the transgenic industry is the case of the Brazil Nut. When DNA from the Brazil nut was spliced into the genes of soybeans to increase protein content, individuals with a sensitivity to Brazil nuts but not soybeans demonstrated an allergic reaction to the soy products produced from the altered soybeans (Marchant et al.). |
| 14 | The common concern with all transgenetic crops to cross-pollinate with their weedy cousins creating difficult to control "superweeds" that could be invasive to nearby natural eco-systems exists here as well. There is interest in the effects on the nutrient value of crops transgenetic engineered to be disease resistant and/or herbicide tolerant (Grogan 46). There is also the possibility of overusing specific antibiotic genes to the point that a bacteria evolves beyond the effectiveness of the antibiotic. |
| 15 | Environmental stress tolerance gene transfers also use the cross-kingdom approach. A common example of gene transfer incorporating this particular trait is the use of a gene from the winter flounder in tomato and potato crops. The flounder gene exhibits cold weather resistance traits in these two crops (Snow). Agriculture products that are resistant to climatic changes would have a longer growing season in some regions, thus increasing crop yields. The ability to thrive in stronger temperate conditions also gives the plant root systems the potential aspect of wintering over. This condition could result in unwanted, self-rejuvenating crops and again the creation of "superweeds" in eco-systems where they would not thrive naturally. |
| 16 | One other topic for consideration regarding the production and use of transgenetic engineered crops is coming from an economical perspective. Because of all the potential adverse effects, genetic scientists are experimenting with gene transfers that would turn on and off certain reproductive regulators, making the seeds produced by these crops non-viable. This would eliminate some of the potential environmental risk associated with these agriculture products. However, this same solution could evoke a system where growers are forced to rely on large corporations for next year's seeds. Farmers generally save seed from the current year to use in the following year. "Because genetic engineering research is so expensive, it is largely controlled by for-profit corporations whose primary goal is return on investments . . . ," allege Grogan and Long. "These corporations are rapidly buying up seed companies and gaining control of entire food-production systems and educational-research facilities." The seed companies respond to this allegation by insisting a variety of non-modified seeds will continue to be available for growers to choose from. |
| 17 | Clearly, further study of transgenetic engineered crops is needed. Their effect on the environment and evolutionary adaptive fitness of all living species could be catastrophic and irreversible over time if they are not carefully regulated and observed. This will require cooperation and information sharing between everyone involved; the growers, seed companies, scientists, ecologists, and the regulating agencies. The results of this technology could have some positive global impacts regarding world hunger, but the potential negative consequences should be shared with all the key stakeholders. Educating the general public with clear and to-the-point facts is key in the future development and application of these agricultural products. |
| 18 | The second issue in the path from point A to point B is the misuse of antibiotics and the adaptive consequences resulting from that misuse. Antibiotic use in agricultural animals provides a good example of the chain of events that occur in creating antibiotic-resistant bacteria. In 1950, Thomas Jukes, a professor in Medical Physics at the University of California, discovered that chicks fed rations containing certain antibiotics grew dramatically faster than chicks fed untreated rations (Lappe Antibiotics 126). This discovery led to the wide use of antibiotics in the raising of livestock. Healthier animals grow faster and larger than animals continually fighting a variety of bacteria. The antibiotics added to the feed are in fairly low doses, just enough to ward off infection, but not enough to kill the bacteria totally. This starts the ball rolling towards antibiotic resistance because the less virulent bacteria are destroyed, leaving the much more resistant bacteria to survive and evolve into even more resistant strains of bacteria. |
| 19 | All living organisms from bacteria to humans are composed of DNA; therefore any genetic adaptation in one species can effect the long term fitness of the other. Farm workers are continually exposed to antibiotics and resistant strains of bacteria by various means, which may include, handling the animals, the feed, or the fecal matter of the animals. This exposure transfers the resistance to them (Fisher et al.). The wide spread use of antibiotics in livestock feed led Dr. Stuart Levy's laboratory group at Tufts University Medical School to conduct an experiment using chickens in a farm atmosphere. They divided the farm's newly hatched chicks into two sections. The first group was isolated from the second group and fed antibiotics. The second group and the farm workers were given no antibiotics during this experiment, nor did the farm workers consume any of the chickens that were being fed antibiotics. Within six months all the chickens and the farm workers were showing resistance to the antibiotic in the first group's feed and some resistance to other related antibiotics, proving antibiotic resistance can transfer from one species to another (Fisher 94). Following this line, anyone who lives within a reasonable distance has a chance of building a resistance to the antibiotics used. Studies conducted on pigs in East Germany during the late 1980s further demonstrates the successful resistance tactics bacteria use to defeat antibiotics, when two years after beginning the use of antibiotics in the pigs' feed, people living in the vicinity began to show resistance to the antibiotics used in the pig feed. If the fecal matter from the farm is used as fertilizer or the livestock products are sold locally, the resistance can and will spread further than the farm over time (Fisher 94). |
| 20 | The widespread use of antibiotics in livestock feed is a major element in creating a crisis regarding the failure of certain antibiotics to treat human diseases. The scope of their use is illustrated by Marc Lappe in his book, When Antibiotics Fail. Lappe states: In 1960, livestock producers used only about 1 million pounds as a feed additive. By 1985, they used over 17 million pounds. In 1980, 75 percent of all cattle, 90 percent of swine and veal calves, 50 percent of all sheep, and virtually all poultry received antibiotics at some time during their production. By 1979, four major antibiotic groups had been approved by the FDA for use singly or in combination as feed stuff additives: penicillin, used principally in poultry and to a lesser extent in swine; tetracyclines, used in all food animals; sulfa drugs, used primarily in swine; and nitrofurans, used in chickens and turkeys, and to a lesser extent in swine. (127)Until the livestock industry agrees as a whole to minimize the use of antibiotics in feed the crisis will continue to evolve. |
| 21 | How bacteria adapt or mutate to evade the effects of antibiotics varies. Bacteria is composed of DNA that is constantly changing because of the very short life span of bacteria. A bacteria species type has the ability to adapt and alter its original DNA make-up more in a day then a human host could in a thousand years (Nesse 51). It does this relatively easily by either spontaneous natural selection, where a resistant gene already present in the overall bacteria is selected for by nature, thus confirming Darwin's concept of fitness, or by gathering tiny loops of DNA from more successful strains of bacteria of its own type or other types (Combating). It can use this DNA to create enzymes that inactivate antibiotics that would destroy the bacterium's cell walls, to restructure its cell walls creating slippery cell walls or gripping cell walls that make it difficult for the body's immune system to grab hold of or let go of it or by mimicking healthy cells of the body. This last tactic opens the access door to healthy host cells, often causing the body's immune system to attack its own cells, virtually shutting down the immune system of the host (Nesse). In his book, Why We Get Sick, Nesse muses, "Bacteria that sneak into the body by pretending to be harmless are rather like Greek soldiers hiding in a wooden horse" (31). |
| 22 | Billions of disease fighting bacteria exist in the human body naturally. It uses the healthy bacteria along with its immune system functions to fight infectious bacteria invasions. When the evasive tactics of the infectious bacteria become too strong for the immune system and healthy bacteria to counter attack, antibiotics are used to strengthen the body's fight. Antibiotics are a bacterial product of a mold or fungi that are non-invasive to the body, but are very effective in destroying disease-causing bacteria. Different families of antibiotics with similar traits are used in this war, depending on the type of bacteria present and its form of attack (Lappe Antibiotics ). However, when environments are created by cultures that are conducive to infectious bacteria evolving and antibiotics are misused, the healing abilities of all antibiotics are compromised. |
| 23 | Beyond farms, hospitals are also ideal environments for creating antibiotic resistance. Exposure to a wide variety of destructive bacteria and broad-spectrum antibiotics are combined with an environment that is intensely sanitized to prevent spread of diseases. This very process selects for the evolution of only the most robust and virulent bacteria (Lappe Breakout 86). Staph infections are a prime example of this resistant-building environment. "In 1941, all such bacteria were vulnerable to penicillin. By 1944, some strains had already evolved to make enzymes that could break down penicillin. Today, 95 percent of staph strains show some resistance to penicillin," Nesse asserts; "In an Oregon Veteran's Administration hospital, the rate of resistance went from less than 5 percent to over 80 percent in a single year" (53). Continued exposure to resistant strains of virulent bacteria in hospital workers and their immediate family members, by close contact with the workers, contributes to the evolution of community acquired resistance. A side effect of antibiotic resistance created in hospitals, is the need for longer hospital stays and rising cost in the treatment of infectious diseases. The Harvard Women's Health Watch claims, "Researchers estimate the cost of treating antibiotic-resistance infections in the United States may be as high as $30 billion annually." |
| 24 | As health care costs related to antibiotic resistance rises, the use and at times misuse of antibiotics by the medical field is being called into question. As stated earlier, there are several families of antibiotics. Choosing which antibiotic to use is usually determined by various types of tests and the overall knowledge of physicians. When physicians prescribe antibiotics without testing for the specific infection type, the possibility of prescribing the wrong antibiotics is greatly increased. Often times to combat this problem, physicians prescribe what is known as a broad-spectrum antibiotic, or one that will combat several different types of bacteria. If the antibiotic doesn't work, the more adaptive bacteria may mutate changes that make them even more resistant to a broader spectrum of antibiotics. Prescribing the wrong antibiotic can be as deadly as prescribing the right antibiotic can be life-saving (Lappe, Antibiotics). |
| 25 | Another side effect of prescribing antibiotics without testing for specific bacteria includes using antibiotics for viral infections. It is common knowledge that antibiotics have no effect on viral infections, however, many physicians feeling pressured by their patients to do something, prescribe an antibiotic in these cases to lull the patient into believing they are being treated. Some physicians prescribe antibiotics when no infection is present in anticipation of exposure due to surgery or some other invasive procedure. This practice only adds to the crisis (Nesse et al.). |
| 26 | When the correct antibiotic is prescribed and taken completely in the correct dosage, an antibiotic can be very effective and even life-saving. However, when doctors misuse antibiotics by over-prescribing them, prescribe a broader-spectrum drug than is needed, use them to treat patients' insistence, and advocate the use of them when an infection is not present, they only add to the growing issue of antibiotic resistance by adaptive evolution of bacteria. The misuse of antibiotics through modern medical practices needs to stop. Marc Lappe says it best with this statement, "This means using a flyswatter and not an elephant gun to kill a fly, and only when the fly is in view" (Antibiotics 102). Better education is needed for both those involved in the practice of medicine and the general public regarding the use of antibiotics when combating infectious diseases. |
| 27 | The lack of new antibiotic discoveries places humans in a continual catch-up mode. No new families of antibiotics have been discovered since the early sixties, only modifications of the existing families have been released. Bacteria that have adapted a resistance to one member of an antibiotic family can easily mutate to overcome a modification in the same family making it harder and harder to treat infectious diseases (Amyes). This prophetic situation brings a new approach to the science of combating disease. The path from point A continues to lead to point B by creating an environment of adaptive changes that have been artificially altered or increased to a more rapid pace than nature intended. Because scientists have been unable to eliminate the bacteria that cause diseases by traditional methods, the new scientific methods used to alter the genetic make-up of plants are being used to alter the genetic make-up of human host immune systems. |
| 28 | In the early 1980s, genetic engineers began mapping the genomes of various bacteria to determine from a genetic approach how their weapons and defenses work. This new approach has helped vaccine makers design live vaccines which, when injected, alter the DNA of the host's immune system defense mechanisms, making them genetically resistant to the targeted disease (Wade). In his book, Genetic Engineering, Charles Swisher provides the following facts: The 1st genetically engineered vaccine, developed in 1986, is a vaccine to prevent hepatitis B. Since then, genetically engineered vaccines have been developed or nearly developed for malaria, cholera, salmonella, typhoid, dysentery and other intestinal diseases. Research is under way to develop vaccines for tuberculosis, leprosy, syphilis, herpes and another form of hepatitis. (55)This on going research is bound to lead to many more genetically engineered live vaccines in the future. Dr. Smith, a Nobel prize winner from the John Hopkins School of Medicine, believes live vaccines could eventually replace antibiotics as a weapon against infectious disease ( Qtd. in Wade 80). |
| 29 | Although this type of genetic alteration affects only somatic cells, or cells containing non-inheritable genes, it is one of the driving forces behind other types of genetic research, still in the developmental stage, that hit point B on the path directly. Gene therapy is one of those methods being explored. Three types of gene therapy are currently being examined: gene insertion, where copies of a normal cell are inserted into a diseased cell in hopes the normal gene will overcome the diseased gene; gene modification, where defective genes are altered by recoding the faulty DNA to a normal sequence right in the living cell; and gene surgery, where defective genes are removed and replaced with healthy cloned substitutes (Swisher 53). |
| 30 | All three of these developmental strategies have the potential of altering the genes that pass on traits to viable offspring. How this effects Darwin's theory of evolution by natural selection, in which nature selects for the adaptations which best increase an organism's fitness, is unknown. As humans continue to play with the process of natural selection, irreversible effects will occur and these artificially created mutations will have a lasting aftermath on the environment and all the living organisms in it. The consequences generated from the path of point A to point B and from point B to the unknown will not be evident until several generations down the road. At that point it will be too late to reverse the fabricated adaptations. |
| 31 | In his book, Remaking Eden, Lee Silver explores one possible path this new technology could lead the human population down. He suggest if scientists are able to cure genetic and infectious diseases by genetic engineering the next step would be to treat social diseases, such as alcoholism and depression, from a genetic approach. Once social diseases are eliminated, scientists might begin looking at other traits that exist in other species such as nocturnal vision or the sonar ability of bats, to enhance the human species. The majority of this research would be funded by private corporations who are at first using the same techniques, so that the alterations are interchangeable. Genetic engineering clinics begin to pop-up in every major city sponsored by four or five major corporations. Eventually there is a noticeable split in the human population of natural humans and the gene-enriched humans, who can afford this new technology. Over several generations, the ability for natural humans and the gene-enriched humans to mate is eliminated, creating two separate human species. As the business of genetic engineering becomes more competitive the major corporations involved begin to alter their techniques just enough so that if a person were to use one companies product, they no longer could use another companies product. These divisions lead to several species of humans. With the new enhancement therapies life spans are increased to the extent over-population of the planet becomes a major issue. Scientist begin to look at the survival abilities of organisms in extreme environments for adaptive traits that will allow humans to survive on other planets (Lee). Remember, all living organisms are composed of DNA. |
| 32 | Although Lee's futuristic scenario is extreme, the potential for it to occur, however small, is there. When computer technology was first introduced the majority of the general population discounted it's potential. Today, that technology is used in almost every aspect of human life. This is just one example of a technology that has altered the human species way of life. Scientist will continue to develop and use genetic alterations in plant life with the hope of addressing world hunger issues. This same technology is being used to open pathways for treating infectious and genetic diseases in the medical fields. Once that is accomplished, crossing the line that leads too the genetic enhancement of humans will become blurred. Clearly, monitoring by everyone and proceeding with extreme caution , while experimenting with this technology, is warranted. The potential for irreversible-catastrophic consequences to all living organisms is to great to be ignored. |
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Nominated by Holly DeGrow, Writing Instructor
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