GM Crops: Helpful or Harmful?
Faith Borrell
Biology Senior Seminar
November 30, 2007
Thesis: Scientists have been able to place genes from one organism into that of a plant to create stronger, better organisms that have been proven safe, help farmers and have substantial nutritional value.
I. Introduction
II. What is a GM Crop?
III. How are GM Crops Made?
IV. Two Needs for GM Crops
V. GM Crops in the World Today
VI. Risks of GM Crops
a) Allergens
b) Superweeds
c) Impact on non-target species
d) Ethical and religious considerations
VII. Benefits of GM Crops
a) Increased crop productivity
b) Enhanced crop protection
c) Improved nutritional value
d) More fresh produce
VIII. Conclusion
IX. Work CitedIntroduction
For centuries, scientists and farmers have been trying to perfect and modify the foods humans consume. One of the pioneers of modern genetics is Gregor Mendel. By cross-breeding tall and short, and yellow and green plants, he came to understand how traits are passed on and the scientific world has praised him ever since. Another huge advancement in technology that has led to the possibility of Genetic Modification is the work of Watson and Crick in discovering the structure of DNA and cracking the genetic code. Because of the work of these scientific geniuses, science has been able to place genes from one organism into another to create stronger, better organisms that have been proven safe, help farmers and have substantial nutritional value.
What is a GM Crop?
A genetically modified (GM) crop is a plant whose genetic code has been altered, subtracted, or added (either from the same species or a different species) in order to give it characteristics that it does not have naturally (Using Genomics, 2006).
How are GM Crops Made?
Biolistics is the primary method used to genetically modify plants. Biolistics involves shooting new genes into the potential host. Microscopic particles of gold or titanium are coated in the DNA sections which are to be introduced to the host. These are loaded into cartridges, similar to shotgun cartridges, and are fired at the plant cells. Biolistics is dependent on some of the microscopic particles entering this cell nuclei and their DNA coating combining with the plant chromosomes (Transgenic crops, 2007). Another method commonly used in plants is protoplast transformation; this is when the cellulose in the plant wall is dissolved away using enzymes leaving a protoplast. DNA can then be added to the protoplast, which are then cultured on a growth media. This encourages the protoplast to re-grow cell walls and eventually grow into a transgenic plant.
Two Needs for of GM Crops
Scientists want to modify crops for two basic reasons. The first is to make them resistant to certain herbicides or pesticides. Much of the seasonal or annual crop yield is lost because the plants become target to different pests. Also, when farmers spray herbicide, there is often some damage to the crops if it is not applied solely to the weeds. The second reason to modify crops is for nutritional enhancement (Genetically modified food, 2007). Scientists desire to modify certain crops that would help to decrease vitamin deficiencies around the world.
GM Crops in the World Today
There are many different kinds of GM crops available to the public, such as maize, soybeans, oilseed rape, corn, squash, chicory and potato. However, policies differ from country to country, and so many crops are only able to be grown in few countries. For example, in 2003, a field test was done in the UK and certain GM crops and they were shown to cause a decrease in biodiversity. Tests like these have led to higher degrees of scrutiny and in 2004 GM sugar beets and GM rapeseed were withdrew from use in the EU (Genetically modified food, 2007). It is interesting to note that while GM soybeans are illegal to grow in Australia, they account for over 50% of the soybeans in the food sold in Australia.
There are only six countries that account for 99% of the global GM crop last year. The United States alone accounts for over 60% of all biotechnology crops planted globally (GM crops in the US, 2006). The US is followed by Argentina, Canada, Brazil, China and South Africa. Twelve other countries, including Australia, Mexico, India and Uruguay, also grew a significant amount of GM crops as well. Between the years of 119 and 2005, the total surface area of land cultivated with GM crops increased by a factor of 50 (Genetically modified food, 2007). The Grocery Manufacturers of America estimate that up to 75% of all processed foods in the US contain a GM ingredient. Unknowingly, most of us are eating genetically modified foods and are still physically well. People can be afraid that the new genes found in food will cause a religious or cultural conflict, but so far, there have not been any genes from cows or pigs placed into foods. As explained later, there are some cases where allergens are a cause for distress but with the safety guidelines now in place, this is no longer something to be worried about.
Risks of GM crops
Allergens
About 2% of people have a food allergen and it is usually only to one or two specific foods (Risks and Benefits, 2007). Many of these people worry about placing genes from one food into another because they feel that if a gene from a food they are allergic to is inserted into another food, they will now become allergic to that food as well. There was a scare when a methionine-enhancing gene from Brazil nuts was inserted into soybeans and 75% of test subjects allergic to Brazil nuts produced antibodies to the GM soybeans (Transgenic Crops, 2007). Since then, screening for allergy problems has become routine. The Food and Drug Administration (FDA) now checks to make sure that the levels of naturally occurring allergens in food made from GM crops is not above the natural level found in conventional foods. What this means is that the FDA makes sure that a food that has not been genetically modified, the potato (for example), does not contain an allergen, then GM potatoes will not contain that allergen. Also, if there was a certain level of allergen in soybeans, GM soybeans will not contain a higher level of that allergen. One of the recent developments and studies with GM crops is scientists are working on removing allergens from peanuts. This is a huge development because peanuts are one of the most serious causes of food allergies.
Superweeds
Many environmentalists believe that if GM crops have an herbicide resistant trait, then that trait can be passed on to surrounding plants and weeds and create superweeds. If a plant is genetically modified to be herbicide resistant, then it is usually only for one herbicide. If a GM crop was able to “escape” and cross-pollinate with a weed, the herbicide that the GM crop is resistant towards may not kill the weed, but another herbicide should. One way that farmers and scientists are working together is by the implicating a “buffer zone” around the crops (Fact Sheet, 2005). This area is dependent on the type of crops planted and is a zone around the field in which usually the same crop will be planted, but will not be eaten. For example, non-GM corn would be planted to surround a field of Bt GM corn, and the non-GM corn would not be harvested. Beneficial or harmless insects would be able to survive in the non-GM corn, and insect pests could be allowed to destroy the non-GM corn and would not develop resistance to Bt pesticides. Gene transfer to weeds and other crops would not occur because the wind-blown pollen would not travel beyond the buffer zone. For Bt corn, the estimate of necessary width of buffer zones range from 18-90 feet (Helpful, 2005).
Impacts on “non-target” species
There has been some dispute about the impact of these GM crops on ecosystems. A study done at Cornell University in 1999 showed that pollen from Bt corn could kill caterpillars of the Monarch butterfly. The study showed that when the caterpillars were fed large quantities of the pollen, half of the larvae died. This made a lot of environmentalists angry and they protested for an end to the use of genetically modified crops. Further field tests showed that under real-life conditions, the caterpillars were highly unlikely to come in contact with the pollen, let alone eat enough of it to harm them (Risks and Benefits, 2007). This example can be applied to many other tests that are conducted. People can skew results to prove almost any argument, but what really matters is real life conditions; water can be deadly if someone has too much of it, but it is still something that we need to survive.
Ethical and religious concerns
Many people do not want to eat genetically modified foods because they think it is dangerous, unnatural and feel that these crops violate certain constraints in their religion. Many of these conceptions are wrong or mislead and more education about GM crops needs to be available to the public. One major argument made against GM crops is that they are unnatural and artificial. It is really important to remember that these same arguments were made against pesticides and herbicides and they are very popular, effective and almost “second nature” in today’s world (Social and Ethical Concerns, 2005). To date, there have been no GM crops that have used genes from animals that may conflict with religious interests. There is one GM crop that has been spliced with genes from a cold water fish to protect against frost and increase productivity. There should be special labels on this crop to let consumers know that there are animal genes contained within this product.
Benefits of GM crops
Increased crop productivity
One of the major devastators of farmers are droughts, especially in third world nations. In America, droughts can still affect a farmer’s crop yield, but they are able to bring water to their field, for a hefty price. What if it were possible to grow an abundance of crops during a drought or with limited water supply? With the help of genetic modification, researchers have been able to place genes from crops that are naturally drought resistant into other crops, thus making them drought resistant. Another devastator is disease. Crops, like people, are able to acquire diseases and need to fight them off. Through genetic modification, crops have been able to become immune to these viruses. For example, much research has been done at Cornell University and the University of Hawaii and they have developed two different varieties of papaya that are resistant to papaya ringspot virus (Risks and Benefits, 2007). The two different types of papaya are “SunUp” and “Rainbow” and their seeds have been distributed freely to papaya farmers since May of 1998. Because of this, the papaya farmers of Hawaii have been able to thrive and the industry has been saved.
Enhanced crop protection
One major ongoing cost to farmers is the purchase of pesticides and herbicides. GM crops can alleviate much of this extra cost because of the “natural” pesticides that are in these new crops. If left uncontrolled, the pest and weed problems would lower crop production significantly. In some cases, a GM crop can be more effective and cheaper than traditional methods. For example, corn that has been modified to contain the Bacillus thuringiensis gene is not just resistant where the gene has been applied, but the whole crop (Risks and Benefits, 2007). Bt is a naturally occurring insecticide found in the soil and some organic farmers do apply it as an insecticide because it is a natural. The organic farmers are being hypocritical because they will use it as an insecticide but will not grow crops that have been genetically modified with this gene. Bt has also been inserted into the Australian cotton plant known as Ingard to make it resistant to the heliothis caterpillar (The Debate over GM Foods, 2006). Usually the caterpillar eats much of the crop and is a major threat to the cotton industry; however with the genetic modification of this crop, the insect is no longer a threat. Because of the crop yields that can be obtained with using GM crops, farmers who may have been struggling to survive are now thriving in this competitive industry.
Improved nutritional value
Today’s world is concerned with the nutritional value of the foods they’re eating. Through the use of genetic modification, soybeans have been developed to have higher protein content, potatoes have been developed with better starches and beans have been engineered with more essential amino acids (Risks and Benefits, 2007). The best known GM crop with improved nutritional value would be “golden rice”. Golden rice is developed to produce beta-carotene, a precursor of vitamin A. “Golden rice” has been able to reach subsistence farmers free of charge and restrictions in poor countries. This effort was part of co-inventor Ingo Potrykus’ proposal to make “golden rice” available to poor farmers (Transgenic Crops, 2007). By giving the rice to poor farmers, it will be able to reach people with vitamin A deficiencies. Golden rice will be able to prevent millions of deaths and permanent blindness in over half a million people annually.
More fresh produce
Genetic modification has resulted in improved produce that does not bruise or decay as easily. This makes for easier shipping and better food on the shelves at markets. An example of this is GM tomatoes. GM tomatoes with delayed softening can be vine-ripened and still be shipped without bruising or decay. The tomatoes will reach the consumer un-bruised and still contain all of the nutrients that otherwise would have been lost, thus making them healthier and more aesthetically pleasing (Transgenic crops, 2007). There is similar research being done with many other vegetables and fruits.
Conclusion
There are many GM crops that are being investigated. Scientists now are trying to produce bananas that have vaccines for Hepatitis B and other infectious diseases. They are also working on fruit and nut trees that yield years earlier (Genetically modified food, 2007). Genetically modified crops have helped farmers around the world and people struggling with vitamin deficiencies around the world. They have improved the life of consumers by providing cheaper, more nutritious produce that lasts longer. There are flaws with everything in this world, but what matters is that the benefits “outweigh” the flaws
Work Cited
Genetically modified crops in the United States (2006). Retrieved October 22, 2007, from Pew Initiative on Food and Biotechnology Web site: http://pewagbiotech.org
Genetically modified food (2007). Retrieved October 20, 2007, from Ministry of Agriculture and Forestry Web site: http://www.maf.gov.nz/
Genetically modified foods – fact sheet (2005). Retrieved October 22, 2007, from Better Health Channel Web site: http://www.betterhealth.vic.gov.au/
Genetically modified foods: Helpful or Harmful? (2005). Retrieved October 20, 2007, from Proquest Web site: http://www.csa.com/
Risks and Benefits of Transgenic Crops (2007). Retrieved October 30, 2007, from Hawaii University Web site: http://www.ctahr.hawaii.edu/
Social and ethical concerns about GM crops (2005). Retrieved October 17, 2007, from 123Biotech Web site: http://www.123biotech.com/
The debate over genetically modified foods (2006). Retrieved October 23, 2007, from ActionBioscience Web site: http://www.actionbioscience.org/
Transgenic crops: An introduction and resource guide (2007). Retrieved October 25, 2007 from the Colorado State University Web site: http://cls.casa.colostate.edu
Using genomics (2006). Retrieved October 22, 2007, from Canadian Museum of Nature Web site: http://nature.ca/