Genetically Modified Crops

Rachel Jackson

I. Introduction

a. issue in society

b. Thesis:

While issues of concern accompany the usage of GM crops, argument can be made to justify their production.

II. History

a. Gregor Mendel and cross-breeding

b. GM no greater risk

c. Other breeding methods

d. GM not a new technology

III. Health Risks

a. Precise engineering makes GM safer

b. Allergens

i. soy-nut example

c. John Innes Center Study

IV. Environmental Risks

a. Superweeds

b. Resistance not because of GM method

c. Monsanto's refuges

d. Monarch Study

V. Benefits

a. Less pesticide

b. higher yields

c. reduce use of harsher pesticides

VI. Conclusion

a. Summary of points

b. Reword thesis

INTRODUCTION

Genetically modified crops (GM crops) climb to the top on the hotly debated issues list of society.  In 1996, no GM crops were cultivated on a commercial scale in the United States.  In 2002, 75% of soya, 71% of cotton, and 34% of all maize grown in America is GM ("Grim Reaper" 1).  Many issues surround this controversial topic such as safety, ethics, and foreign relations.  Many of these concerns are well stressed in mass media, but sometimes biased views are the only ones presented.  Safety with human health and the effects on the environment appear to be the strongest and most discussed subject matter.  While issues of concern accompany the usage of GM crops, argument can be made to justify their production. 

HISTORY

What many people do not know is that genetic modification has been going on since the founder of Genetics, Gregor Mendel, cross- bred his pea plants for different affects.  Many of the flowers sold and bought in our society are mutations and mixing of genes.  "The corn we eat today is the result of decades of· self-pollination followed by cross-pollination to produce vigorous hybrid plants" ("History" 3).  For well over a century, playing with genes has given humans a more cost and space efficient means of mass-producing plants, whether that is corn, potatoes, strawberries or flowers.   The National Research Council met in 1989 to discuss some concerns over field testing of GM organisms (GMOs).  A report from the National Academy of Science said, "Crops modified by genetic engineering should pose risks that are no different from those of cops modified by classical genetic methods" (Hokanson 1).  These classical methods range from Mendel's cross-breeding to wide-cross methods, to using radiation for mutations. 

Starting in the 1920s for example, researchers created many mutant genes in order to use in breeding.  Plants were bombarded with "gamma rays, protons, neutrons, alpha particles, and beta particles" in order to create any valuable mutation ("History" 5).  Induced mutation breeding, starting in the 1950s, used ionizing radiation or toxic chemicals to produce desirable mutations.  "Thousands of mutation-bred crops have been commercialized in North America and Europe" (Miller 12).  Another more recent example using a traditional method is a new manmade species of wheat.  An entire extra genome from quackgrass was bred into the wheat through a wide-cross.  This is where a crop and a related wild species are hybridized; many genes are inserted into plants to create varieties that cannot exist in nature.  Instead of one specific gene, tens of thousands are being used in animal feed and human food in this wheat hybrid. 

Introducing new genes into the environment for human benefit has been done since the domestication of plants.  Nick Middleton from Geographical Magazine said, "There is absolutely nothing new in principle about biotechnology and genetic engineering.  It is simply that the techniques we use to achieve these age-old aims have become more precise as our understanding of the processes involved has improved." (Middleton 2)  The technique has now become as precise as to breed only one gene in one generation of plants.  An example of such a specific gene is used with bacteria that produce insulin.  The gene responsible for making human insulin was inserted into a certain bacteria.  The insulin cultivated by the bacteria has been used for years by people with diabetes.  This genetic transfer would never have been possible through "natural" means (Middleton 2).  No long term side affects have been documented.

HEALTH RISKS

Health risks, or assumption thereof, play a key role in the doubting minds of consumers.  Questions such as, "What are the long term health risks of eating GM foods?  Do GM foods cause allergic reactions?  Does eating foreign DNA pose risks for my body?" are suspicions made by society about consuming GMOs.  While some information sources claim that biotechnology is a bad idea with many untested risks, these accusations are not true.  The Organic Consumers Association stated, "Genetic engineering is a radical new technology, one that breaks down fundamental genetic barriers," and, "Biotechnology is an imprecise science and scientists will never be able to ensure a 100 percent success rate" ("What's Wrong" 1). 

Genetic engineering has been happening since the start of agriculture, as previously mentioned.  Genetic barriers are broken with the fertilization of each generation by passing genes from both parents.  Many organic growers breed or use seeds bred for a higher yield or some other benefit.  Traditional breeding transfers many genes without control, yet genetic transfers are said to be "imprecise".  Ohio State University scientists said just the opposite, "Genetic engineering is far more precise·it allows a single gene to be introduced."  The insulin bacteria are an example because only the gene making insulin was introduced, not a gene coded for any other function.  Those scientists also bring up the apparently overlooked point that, "The safety of food depends upon its properties, not the process used to produce it" ("GMO" 1).  Critics often use two examples in effort to prove the possible harm in GM foods.  One is the test of a Brazil nut gene put into soybean species in order to create a high-protein product.  Pioneer Hi-Bred International used the gene's protein making factor, but in testing found the soybean caused allergies to people allergic to the nuts.  Since Pioneer could not find a way around using the nut, they "decided not to ask for approval to market the soybean.  It was never approved by the government and was never grown commercially or sold in stores ("Risks" 1). 

The other major example, not relating to allergies, of potential harm of GMOs, involves testing of potatoes on rats.  Dr. Arpad Puztai from the Rowett Research Institute claimed that rats that ate GM crops had damage to their organs.  A report from the John Innes Center, Europe's premier independent centre for research and training in plant and microbial science, said,

"The GM potatoes contain a gene for a lectin, a type of protein known to be toxic. These were experimental potatoes not intended as a human food. Is it surprising that a normal food item to which a toxin is added is toxic, however it was added? As was said by the UK Chief Scientific Adviser "If I mix cyanide with Vermouth and find the resulting cocktail unhealthy, I would be silly to draw the conclusion that I should never mix drinks". How does this analogy work?" (Clare 3).

ENVIRONMENTAL RISKS

Another major controversy of GMOs is the potential risk of creating a "superweed" resistant to herbicides.  Hybridization from pollen of transgenetic crops to nearby weeds "may enable weeds to acquire traits·such as resistance to herbicides," says the Center for Life Sciences and Department of Soil and Crop Sciences at Colorado State University.  This theory is quite possible, but also misused to advocate a bad image for GMOs.  These nearby weeds must be "sexually compatible" in order to hybridize with GM crops.  There must also be "favorable conditions".  In the United States, there are no wild relatives of corn, cotton, potato, or soybeans, and wheat and soybeans are self-pollinating, " so the risk is·small" ("Risks" 10). 

In 2000, a team from the Cooperative Research Center for Australian Weed Management and the University of Adelaide composed a comprehensive study of pollen movement with canola fields.  Crops mutated (not GM crops) to resist herbicides were planted with conventional canola.  Although the gene traveled almost 2 miles, "only a small proportion of conventional plants" were contaminated.  The highest percentage of resistant seeds found mixed in was 0.07%, and the "vast majority·less than 0.03%."  The report in Science Now also quoted plant geneticist Rikke Jorgensen of the Riso Nation Laboratory in Denmark saying, "Canola is one of the more problematic in terms of gene flow.  This is a worst-case scenario" (Stokstad 1).  While gene transfer can happen, there is not yet any evidence that weeds have benefited from the acquisition of crop pest resistance genes. 

Michael Crawley, professor of plant ecology at Imperial College, London, began a study in 1990 of all GM crops available at the time.  Four crop species: maize, beet, rape, and potatoes were planted with versions of the same species with no foreign genes.  Tests showed that 47 of 48 test plots went extinct within four years without human intervention.  The remaining potato plot contained "all of the traditional sort" ("Genetically" 79).  Giving the weeds the benefit of the doubt, one can assume that herbicide resistant weeds can be created from gene transfer.  If so created, the weeds would be resistant to one specific herbicide.  "Weeds resistant to all control measures, are not a possibility·if this happened farmers would switch to other control measures." ("GMO" 3)  That too is given as a worst-case scenario.  Since weeds can and often do adapt to herbicides, one must also assume that weeds may have a recessive resistant gene within their own gene pool.  A "superweed" may also arise by natural selection from using herbicides alone.  One can also assume that eventually, resistant weeds will appear on the scene through years of selection with conventional farming.  The threat is the same regardless of using conventional herbicides or GM crops.  The same idea can be applied to insects adapting to resist pesticides.

            A report from Iowa State University discussed the adaptation of pests to herbicide resistant crops.  These crops, however, were of the traditional sort, meaning that breeders had developed crops from naturally resistant genes for use on the pests.  "All too often ·the resistance lost its effectiveness after a few seasons·insect and disease pests are highly divers genetically" (Duvick 2).  Insects became adapted because of conventional insecticides.  "Entomologists say 500 crop pests have already evolved" ("Field" 3).  This problem can easily be avoided by not using pesticides on crops.  Insects will continue to modify their genetic information using GM resistance or conventional methods. 

A more reasonable solution is required by Monsanto, a leading global provider of agricultural products.  Monsanto requires farmers to "devote a certain acreage to refuges," acres of crops without genetic resistance.  These refuges are "sprayed with conventional insecticides" for the purpose of diluting insects with resistant genes.  "Thus if any resistant bugs develop, their resistance genes would- theoretically- be swamped in the larger population of susceptible insects" ("Field" 5).  One can say that insect resistance will happen eventually in spite of GM crops, but this cannot justify using them.  However, using this argument against their usage is ineffective.  Farmers will continue to use pesticides as pests continue to become adapted to them. 

MONARCH BUTTERFLY

The final argument in opposition to GMOs stems from claims of harm done to innocent organisms in the environment.  The infamous Monarch butterfly study and the drifting and contamination of nearby organic crops can be disputed.  In May of 1999, a Cornell University study claimed that monarch caterpillars were at risk from Bt corn pollen that settled on milkweed leaves.  Bt corn is a genetically modified crop created to produce their own insecticide, the Bacillus thuringiensis (Bt) delta endotoxin.  The Cornell group tested one type of many Bt corn pollen products in the laboratory with a no-choice method of a food source.  The densities of pollen on the milkweed leaves were not subject to measurement, and an article in Agricultural Research said leaves were "heavily coated with Bt corn pollen," and were above natural conditions.  Research done through Crop Protection and Quarantine and the Agricultural Research Service measured, in the field, pollen deposition and amounts of Bt pollen eating that showed affects.  Their study concluded that densities below 1000 grains/cm squared "had no effect on caterpillars," and, "inside corn fields, pollen levels exceeding 1,000·[is] less than 1 percent of the time" (Kaplan 18).  Agricultural Research reminded readers that corn pollen is relatively heavy, higher milkweed leaves are more often pollinated rather than lower leaves caterpillars prefer, corn pollen is shed for only 1-2 weeks of the year, and rain washes pollen from the leaves.  The article also claimed, "Given the low toxicity of Bt corn pollen and the low rates of exposure, the effect·is negligible."  Bt pollen would logically be relatively toxic given that it was put into corn as a pesticide for corn borers.  Given the "negligible" effect from this as compared to the alternative, "which is chemical insecticide use," the logical choice would not be to scrap GMO usage.             

BENEFITS

Biotechnology can be seen not only from the defensive perception, but in light of the benefits to verify its vital existence.  Monsanto Co. gave canola elevated levels of vitamin A.  A rice species has also been developed for vitamin A.  Probably the most common genetic change is for resistance to herbicides and insects.  The alternative for traditional pesticides is crops that make their own resistance.  Consumers Research Magazine stated in an article, "GM crops lead to less pesticide use." (Hunter 24.)  Pesticide sprayed on crop land leads to many well-known environmental problems: run-off of toxins into water sources, loss of wildlife, and eventual resistance build-up of insect and weed pests.  While GM crops cannot solve all environmental problems, it greatly reduces "soil erosion·use of herbicides, and eliminate use of some of the more environmentally suspect herbicides" (Duke 1).  Biotechnology can increase the productivity of crops·reduce the costs of production by decreasing the inputs of pesticides.  Often times, crops are modified in order to "give better rotations to conserve natural resources, keep much longer in storage and transport, and continue low cost food supplies to consumers" (Persley 2).  The increase yield can be used to feed the ever increasing human population.  Senior Editor Fred E. Foldvary, The Progress Report, said, "The food supply will with come from turning more natural forests and grasslands into farms, or by increasing the yield of current farmland."    Current food productions have not met the need for world hunger.  GMOs may bring a possibility of assistance in the fight of world hunger.  Future applications could enable crops to be grown in less fertile areas. Drought resistance could be built into plants to enable them to grow in arid conditions, whilst plants made resistant to frost could grow in colder climates.  Dr Patrick Moore, one of the founders of Greenpeace, has argued that if all farming were to be organic, productivity would be so low that forests around the world would have to be destroyed to make way for agricultural land.  He also stated, "genetic engineering was a good way to reduce humans' impact on the environment ("Public" 5).

CONCLUSION

Many arguments have been published in the controversy over genetically modified crops and organisms.  Claims on the safety to human health and the environment from the production and usage of these crops are prevalent in the news and also in the scientific community.  Such cries for testing and safety procedures never arose over traditional farming methods.  Only in the latter half of the twentieth century did concerns of pesticide use come on to the public scene.  Testing with radiation and mutations, as well as different types of cross-breeding are sources of untested and unnatural genetic flow.  Throughout the history of agriculture, genetic crosses have been the leading technology in better farming practices.  Many problems developed in the public mind can be looked at from a logical standpoint with more objective perceptions and publication of information.  While there are many arguments surrounding GM crops, validation can be found for support of testing and future consumption of GM crops.     

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12/03/2002