Traditional plant breeding involves crossing varietiesof the same species in ways they could crossnaturally. For example, disease-resistant varieties ofwheat have been crossed with high-yield wheat tocombine these properties. This type of natural gene exchange is safe and fairly predictable.
Genetic engineering ( GE) involves exchanging genes between unrelated species that cannotnaturally exchange genes with each other. GE can involve the exchange of genes betweenvastly different species — e.g. putting scorpion toxin genes into maize or fish antifreezegenes into tomatoes. It is possible that a scorpion toxin gene, even when it is in maizeDNA1, will still get the organism to produce scorpion toxin — but what other effects may ithave in this alien environment? We are already seeing this problem — adding human growthhormone genes to pigs certainly makes them grow — but it also gives them arthritis andmakes them cross-eyed, which was entirely unpredictable.
It will be obvious, for example, that the gene for human intelligence will not have the sameeffect if inserted into cabbage DNA as it had in human DNA— but what side-effect would ithave? In other words, is GM food2 safe to eat? The answer is that nobody knows becauselong-term tests have not been carried out.
Companies wanting a GM product approved in the UK or USA are required to provide regulatorybodies with results of their own safety tests. Monsanto’s3 soya beans were apparently fed tofish for 10 weeks before being approved. There was no requirement for independent testing,for long-term testing, for testing on humans or testing for specific dangers to children orallergic4 people.
The current position of the UK Government is that"There is no evidence of long-term dangersfrom GM foods."In the US, the American Food and Drug Administration5 is currently beingprosecuted for covering up research that suggested possible risks from GM foods.
Ⅰ. Match the words with their Chinese quivalents:
1. disease-resistant A. 掩盖( 真相)
2. side-effect B. 高产的
3. long-term dangers C. 长期危害
4. cover up D. 副作用
5. high-yield E. 抗病的
What do companies wanting a GM product approved in the UK or USA do?
Ⅰ. 1. E 2. D 3 . C 4. A 5 . B
Ⅱ. They are required to provide regulatory bodies with results of their own safety tests.