Agriculture is commonly considered to have begun about 10,000 years ago, and crops have been continuously improved ever since. New crop varieties have been developed to improve such properties as nutritional quality, yield and harvestability, as well as to remove mammalian toxins. By identifying favorable traits in individual crop plants or their wild relatives, breeders can cross such individuals with commercial lines to create new, improved lines. Mutations―arising, for example, through chemical treatment or radiation―are also used to introduce new genetic variation that breeders can use when seeking new traits. Traditional breeding has a very safe history.
However, traditional breeding is typically slower, more expensive, less precise and often less effective compared with modern biotechnological techniques used to obtain similar desirable crop traits. Finding genes or mutations that achieve a desired phenotype by traditional means is often a very difficult process that can take many decades or longer. In traditional breeding, many genes are brought into crop plants that are unrelated to the desired phenotype. These unrelated genes (and even the genes responsible for the desirable phenotype) are typically unknown and untested for human safety. These genes may be very rare in the crop plant, may have been generated by intentional or unintentional mutation or may come from wild relatives of the crop having no history of safe consumption.
The gap left by this traditional process is precisely the reason that GM crops have been so successful. Indeed, many valuable traits, such as high levels of insect protection that have no effects on humans or other animals, are unlikely ever to be identified through conventional approaches. The full characterization of the transgenes, resulting gene products (usually proteins) and endogenous plant-DNA insertion site for a GM event makes modern biotechnological techniques more precise. The improved knowledge and ability to control the outcome of crop improvement through GM processes substantially increases the efficiency of crop improvement and reduces uncertainty with regards to the effectiveness and safety of the resulting crop lines. In conclusion, GM crops often offer a faster, cheaper, more precise and more effective means to obtain desirable and safe crop traits compared with traditional breeding methods.