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The below mentioned article provides notes on genetically modified crops (GM).
When potential risks to the environment from new genetically modified (GM) crops are discussed, the focus is generally on risks of genes escaping to wild relatives that become “super-weeds,” risks of crops themselves becoming weeds, and the potential that toxins produced by the GM crops will harm non-target organisms. These are all tangible risks, that can be diminished if taken seriously.
Their worst-case negative impacts on the overall environment in developing countries are relatively small compared to the impact on the environment of rural populations without food security and living in poverty. 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.
The new genetic modification has great potential for increasing yield and decreasing yield variation, but that such accomplishments will require vigilance by scientists and society. Giving farmers the right kind of seeds can never ensure food security, but giving them the wrong kind of seeds always can make things worse.
Social scientists know that you cannot alleviate poverty just by growing more food, but agricultural scientists are always being pushed by philanthropic and development organisations to produce more food because food production is a necessary but not sufficient condition for food security.
This has led to increased yield becoming a focus of international attention. About 50 years ago agricultural scientists were told that the growing world population would demand that substantially increase crop yields.
Amazingly, agricultural scientists, with the financial aid of many government and private organisations, did a reasonable job of meeting this demand. Today agricultural scientists are being told to do this again because world population growth by the year 2025 or so will demand that increase production by 30-50 per cent.
One thing that crop and animal breeders have learned over the years is that when you select strongly for improvement in one trait of an organism, be it speed in a race horse, appearance in a dog, or yield in a crop, there are trade-offs.
The race horse may be frail, the dog less intelligent, and the crop less capable of dealing with stress. There has always been support given to programs that breed for stress resistance, but these programs are often funded with the goal of increasing yield rather than decreasing variation in yield.
A number of recent reviews have attempted to determine if the variation in crop yields have changed during the 20th century. The conclusions of these assessments indicate that on a global and continental level overall adjusted variation in yield has not generally increased, but that the component associated with genetic crop improvement has increased.
This means that the variation in yield is being pushed upward by the varieties of crops grown, but that other factors such as improved irrigation may be balancing out this increase caused by breeding.
Because at the local level, drought, flooding, and pests vary significantly from year to year, cultivars bred with resistance or tolerance to any of these disruptive factors would decrease yield variation and could also result in increased average yield. Genetic engineering has improved and should continue to improve, these traits, but care must be taken in how this is done if a major goal is decreased variability in yield.