The benefits and risks of any particular GM crop depend on the interactions
of its ecological functions and natural history with the agroecosystem and
ecosystems within which it is embedded. These evolutionary and ecological
factors must be considered when assessing GM crops. We argue that the asses
sment of GM crops should be broadened to include alternative agricultural p
ractices, ecosystem management, and agricultural policy. Such an assessment
would be facilitated by a clearer understanding of the indirect costs of a
griculture and the ecological services that support it. The benefits of GM
crops should be compared to those of other means of agricultural intensific
ation such as organic farming, integrated pest management, and agricultural
policy reform. A gradual and cautious approach to the use of GM crops that
relies on a truly comprehensive risk assessment could allow people to reap
substantial benefits from GM crops while mitigating their serious risks.