Because poverty can lead to environmental degradation, a potential chain of interactions between genetic modification, increased yield, variation in yield, food security, and environmental degradation is examined. The potential for genetic modification to increase yield and decrease yield variation is explored. Sections cover importance of yield stability, and pest resistance management and yield variation; a case history of Bacillus thuringiensis (Bt) is presented and Bt resistance management is discussed. Implications for developing countries are considered and the case of Bt resistance management in rice is reviewed. Regulatory requirements to ensure biosafety are outlined.