Recent developments in scientific plant breeding have resulted from discoveries in molecular and cellular biology in the second half of the 20th century that laid the foundation for the development of genetically engineered plants. In 1973, the American biochemists Stanley Cohen and Herbert Boyer were among the first scientists to transfer a gene between unrelated organisms successfully. They cut DNA from an organism into fragments, rejoined a subset of those fragments, and added the rejoined subset to bacteria to reproduce. The replicated DNA fragments were then spliced into the genome of a cell from a different species, and this created a transgenic organism, that is, an organism with genes from more than one species. Before the advent of genetic engineering, plant tissue-culture technology expanded the array of available genetic material beyond what was possible with traditional plant breeding by manipulating the fertilization and embryos of crosses between more distantly related species (Brown and Thorpe, 1995). DNA-recombination techniques opened the possibility of augmenting plant genomes with desirable traits from other species and thus took the science of plant breeding to a stage in which improvement is constrained not by the limits of genetic traits within a particular species but rather by the limits of discovery of genes and their transfer from one species to another to confer desired characteristics on a particular crop.
The committee’s study was the first comprehensive assessment of the impacts of the use of genetically engineered (GE) crops on farm sustainability in the United States. The most up-to-date, available scientific evidence from all regions was used to assemble a national picture that would reflect important variations among regions. Box 1-1 presents the formal statement of task assigned to the committee.
In conducting its task, the committee interpreted the term sustainability to apply to the environmental, economic, and social impacts of genetic-engineering technology at the farm level. That interpretation is in line with the federal government’s definition of sustainable agriculture, which is “an integrated system of plant and animal production practices having a site-specific application that will over the long term:
Satisfy human food and fiber needs.
Enhance environmental quality and the natural resource base upon which the agriculture economy depends.
Make the most efficient use of nonrenewable resources and on-farm resources and integrate, where appropriate, natural biological cycles and controls.