英文议论文素材大全——转基因食品的利与弊

Pros Cons

Genetic modification is unnatural. There is a fundamental difference between modification via selective breeding and genetic engineering techniques. The former occurs over thousands of years and so the genes are changed much more gradually. Genetic modification will supposedly deliver much but we have not had the time to assess the long-term consequences. In addition, many of the claims made by the companies have now been shown to be false. For example, a recent study by the Soil Association shows that GM crops do not increase yield. Another example is a frost-resistant cotton plant that ended up not ripening. Genetic modification is entirely natural. The process of crop cultivation by selective breeding, which has been performed by farmers for thousands of years, leads to exactly the same kind of changes in DNA as modern modification techniques do. Current techniques are just faster and more selective. In fact, given two strands of DNA, created from the same original strand, one by selective breeding and one by modern modification techniques it is impossible to tell which is which. The changes caused by selective breeding have been just as radical as current modifications. Wheat, for example, was cultivated, through selective breeding, from an almost

no-yield rice-type crop into the super-crop it is today.

It is wrong to introduce the DNA of one species into the genes of another - e.g. using fish genes in tomato plants to make them frost-resistant. This attempt to 'play God' is short-sighted and unnatural. It is perfectly natural and safe to introduce genes from one organism into another. We must remember that all DNA is made up of the same four fundamental molecules regardless of which organism the DNA came from originally. It is also worth noting that DNA from all organisms is very similar. Human DNA is 99% the same as chimpanzee DNA and about 50% the same as grass DNA. Consequently, the addition of genes from one organism into the DNA of another is like adding Lego bricks to one another to create a desired final structure. Indeed such processes occur all the time in nature in sexual reproduction.

There are two problems associated with scientifically testing the impact of genetic modification of food. 'Peer review' (the checking of scientific test results by fellow scientists) is often made impossible by the unwillingness of biotechnology companies to give up their results for review. Monsanto, for example, has never published even one of its results. Furthermore, government agencies are often unwilling to stop GM foodstuffs reaching the shelf because of the clout that the companies have with their government. This debate should be decided on the basis of hard facts, not woolly assertions and environmental sentiment. Until scientific tests show there to be some real risk of harm from farming and eating GM food there is no case for a ban or a moratorium. Not only is genetically modification natural and well understood but extensive testing is applied to every new GM foodstuff before it is placed on the market. This testing takes two forms. Peer review by other scientists and testing by the food standards agency in whichever country the product is to be marketed. For example, in the United States all GM food must be tested for nine years before its release onto the market. In fact, testing has been so successful that in the 30 year history of GM food not one single person has died due to genetic modification.

GM food will do nothing to help solve the problems in developing countries. The problem there is not one of food production but of an inability to distribute the food (due to wars, for example), the The possible benefits from GM food are enormous. Modifications which render plants less vulnerable from pests lead to less pesticide use which is better for the environment. Other