Genetically Modified Foods

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From Cross-Breeding to Genetic Engineering

• Farmers have used artificial selection (Cross-Breeding) to develop genetically improved crops– Takes 15 years or more

• Genetic Engineering– Changes to DNA– Faster– More versatile

Early Genetically Altered Crops

• Flavr Savr tomato:– Advantage: longer shelf life– 1992: FDA approved– 1994: on the market– Business issues sunk Celgene

• Bt cotton plants: – Advantage: resistant to insects

• Several crops:– Advantage: resistant to Roundup (allows no-

till)

Objectives of Genetic Modification

• Resistance to disease• Increase tolerance for environmental conditions• Improve nutritional value• Incorporation of human vaccines (a stretch)

Biotech Crops (% of total)

Pros and Cons

• Less fertilizer• Less water• More resistant to

insects, drought, frost, etc

• Faster growth• Can tolerate salt• Less spoilage• Better flavor• Less pesticide• Can tolerate higher

levels of herbicide• Higher yields

• Unpredictable and probably irreversible genetic and ecological effects

• Potentially harmful toxins/allergens in food

• Lower nutrition• Increased selection for

pesticide-resistant insect and plant diseases

• Creation of herbicide-resistant weeds

• Harm beneficial insects• Lower genetic diversity

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