As debate rages over the costs and benefits of genetically engineered crops, noted agroecologist Miguel Altieri lucidly examines some of the issue's most basic and pressing questions:

• Are transgenic crops similar to conventionally bred crops?
• Are transgenic crops safe to eat?
• Does biotechnology increase yields?
• Does it reduce pesticide use?
• What are the costs to American farmers?
• Will biotechnology benefit poor farmers?
• Can biotechnology coexist with other forms of agriculture?
• What are the known and potential environmental and biological risks?
• What alternatives do we have to genetically modified crops?