Biology For Dummies
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Genetic modification has its upsides. After all, gene therapy to cure genetic diseases is a type of genetic modification. In addition, genetic modification can make growing crops easier and boost the profitability of those crops. It may even help improve human health by increasing the nutritional content of some foods. Here are a few specific scenarios that illustrate how GMOs can be beneficial:
  • If crop plants are given genes to resist herbicides and pesticides, then a farmer can spray the fields with those chemicals, killing only the weeds and pests, not the crop plant. This is much easier and less time-consuming than labor-intensive weeding. It can also increase crop yields and profits for the farmer.
  • If crop plants or farm animals raised for human consumption are given genes to improve their nutrition, people could be healthier. Improved nutrition in crop plants could be a huge benefit in poor countries where malnutrition stunts the growth and development of children, making them more susceptible to disease.

One of the most famous examples of improved nutrition through genetic engineering is the creation of “golden rice” — rice that has been engineered to make increased amounts of a nutrient that’s necessary for vitamin A production. According to the World Health Organization, vitamin A deficiencies cause 250,000 to 500,000 children to go blind each year. The company that produced golden rice is giving the rice to poor countries for free so they can grow it for themselves and make it available to people who need it.

  • If farm animals raised for human consumption are given genes to increase their yield of meat, eggs, and milk, then more food may be available for the growing human population, and these greater yields may also increase profits for farmers. Currently, many dairy cows are given recombinant bovine growth hormone (rBGH) to increase their milk production. BGH is a normal growth hormone found in cows; rBGH is a slightly altered version that’s produced by genetically engineered bacteria. When rBGH is given to cows, the animals’ milk production increases by 10 to 15 percent.
What make GMOs so controversial are the ethical concerns. The list of concerns surrounding genetic modification is long and so serious that some countries in the European Union have banned the sale of foods containing products from GMOs. The concerns expressed include the following:
  • The use of GMOs in agriculture unfairly benefits big agricultural companies and pushes out smaller farmers. Companies that produce seeds for genetically engineered crops retain patents on their products. The prices on these seeds can be much higher than for traditional crops, giving large agricultural companies an advantage in the marketplace. This issue is particularly worrisome when large agricultural companies from rich nations start competing in the global economy with smaller farmers from poor countries.
  • The use of GMOs in agriculture encourages unsound environmental practices and discourages best farming practices. Farmers who plant crops engineered for pesticide or herbicide resistance use chemicals rather than manual labor to control weeds and pests. Not only do these pesticides and herbicides affect the health of plants and animals living in the area around farms but they can also get into the drinking water and possibly affect human health. Also, large-scale plantings of just a few species of plants decrease the genetic diversity in food species and put the food supply at risk for large-scale catastrophes should one of the crop species fail.
  • Animals that are engineered to produce more milk, eggs, or meat may be at greater risk for health problems. Cows treated with rBGH to increase milk production get more infections in their milk ducts and have to be treated with antibiotics more often. Overuse of antibiotics is a human health concern because it reduces the effectiveness of antibiotics on bacteria that cause human infections.
  • Cross-pollination between genetically engineered plants and wild plants can spread resistant genes into wild plants. Farmers can put up fences, but wind blows all over the place. If a crop plant that contains a gene for herbicide resistance can pollinate a wild plant, then the wild plant could pick up that gene, creating a weed species that can’t be controlled.
  • Increased levels of bovine hormones in dairy products may have effects on humans who drink the milk. When rBGH is injected into cows to pump up their milk production, the levels of IGF-1 (an insulin-like protein) in their bodies and milk increase. Human bodies also make IGF-1, and increased levels of this hormone have been found in patients with some types of cancer. People are worried that increased IGF-1 in milk from hormone-treated cows may put them at greater risk for cancer, but no clear link has yet been found between IGF-1 in milk and human cancer.
  • Genetic modification of foods may introduce allergens into foods, and labeling may not be sufficient to protect the consumer. People who have food allergies have to be very careful about which foods they eat. However, if foods contain products from GMOs, it’s possible that the introduced genes produced a product that’s not indicated on the food label.
  • Fear of “unnatural” practices and new technologies makes people afraid of GMOs and lowers their value in the marketplace. Some people see humans as becoming out of balance with the rest of nature and think we need to slow down and try to leave less of a footprint on the world. For some, this belief includes rejecting technology that alters organisms from their natural state.

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René Fester Kratz, PhD, teaches biology at Everett Community College. Dr. Kratz holds a PhD in Botany from the University of Washington. She works with other scientists and K?12 teachers to develop science curricula that align with national learning standards and the latest research on human learning.

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