Food has become a battleground, and one of the fiercest fights involves genetically modified organisms, or GMOs. With the aid of genetic engineering, we have created corn, soybeans, cotton and other crops with specific genes that help them resist pests, diseases and herbicides. Supporters trumpet the reduced costs and increased yields, especially in the developing world. They also point to the ability of GMOs to prevent diseases from ruining entire industries, such as Hawaiian papayas and Florida oranges.