Genetic modification can be dangerous and unpredictable.
But on the other hand, many professional independent observers believe genetic engineering is unpredictable and dangerous. They think that the risks are not worth taking, especially since they are not safe. This science is too new to guarantee that problems will not occur in the future. When moved from one species to another, genes can create new unknown dangers. Small changes could have big impacts. Once released into the natural environment, genetically modified plants interbreed with those in the wild. The spread of modified genes from one organism to another in the wild is technically termed "a gene flow". It has already led to the creation of new strains of "super weeds" that are resistant to herbicides. Perhaps most worrying of all, there is no way of recalling a genetic modification. Once released into the environment, genetic pollution cannot be cleaned up; it will survive so long as there is life on Earth. The environment will be irreversibly altered. Natural plants and animals could be driven out.
Mistakes have already been made in genetic engineering. Use of genetically modified bacteria in the food supplement Tryptophan may have caused 37 deaths in the USA since 1989 as well as permanently disabling thousands of people.
A company called Pioneer Hi-Bred developed a variety of genetically modified soya spliced with a Brazil nut gene to increase its protein content. When it was discovered that individuals allergic to Brazil nuts also reacted to the modified soya, the company had to withdraw the product.
In a 1994 field test, natural potatoes were planted at a distance of up to 1,100 metres from a batch of genetically modified potatoes. When seeds from the unmodified potatoes were later collected, it was found that 72% of the natural plants grown near the modified batch had absorbed the modified gene, and 35% of those grown further away had also done so. In another study in the same year, scientists at the Scottish Crop Research Institute found that pollen from genetically modified rapeseed had fertilized plants up to 2.5 kilometers away.
The company Ciba Geigy PLC recently introduced genetically modified maize, which is altered to be resistant to a herbicide and contains a marker gene for resistance to the widely used antibiotic ampicillin. Microorganisms in the stomach could absorb the gene for resistance to the antibiotic and spread into the environment, leaving a vita medical resource useless. The European Parliament expresses fear that consumption of the maize might weaken the effect of some antibiotic medicines in the human body. And the finite risk could be absolutely catastrophic if it occurred.
A soil bacterium was modified to break down a particular herbicide. It did so, but the unexpected end result was a substance highly toxic to vital soil fungi, which were destroyed.
Now just twenty-odd years since this was discovered, experiments have produced genetically modified types of most major food crops and these have recently started to be given legal approval despite opposition from thousands of organizations who have high lighted the dangers, and without informed public debate. A report by 100 US scientists suggested that genetically modified organisms could cause "... irreversible, devastating damage to the technology". British scientists have also spoken out – Dr. Michael Antoniou, a senior molecular biologist who has experience in conducting genetic engineering experiments in the laboratory said: "This is an imperfect technology with inherent dangers". The Prince of Wales also speaks out about genetic foods. He urges scientists to stop playing God by tinkering with food. He says there is no way of knowing the long-term consequences of producing and eating genetically modified crops, and points to the "man-made" BSE1 disaster an example of the dangers of the quest for cheap food. The Prince says that genetic engineering "takes mankind into realms that belong to 'God and to God alone', "and raises ethical and practical considerations. "Apart from certain highly-beneficial and specific medical applications, do we have the right to experiment with and commercialize the building blocks of life? We live in an age of rights – and it seems that it is time that our Creator had some rights too." Later, an article from The Daily Telegraph continues, "We simply do not know the long-term consequences for human health and the wider environment of releasing plants bred in this way ... The lesson of BSE and other entirely man-made disasters on the road to "cheap food" is surely the greatest cause for concern. Even the best science cannot predict the unpredictable."
The author of a report on genetic engineering from Brussels, Doug Parr, says, "It's like the genie in bottle: once it's out, you cannot put it back. Already there are too many cases of things going wrong."
Susan Leubuscher of Green Pease's European Unit in Brussels says, "The science of genetic engineering is unpredictable, but few, from scientists to governments, dare raise the fact that today's Golden Goose of industry is laying some rotten eggs." 
The problems of labeling genetically modified food.
Do not be surprised if you have not heard much about genetically modified foods, because neither the chemical companies who produce them nor the governments are exactly running public information campaigns about them. Agricultural biotechnology is big business, and science has been absorbed into industry to an unprecedented extent. Practically all established molecular geneticists have some industrial ties, thus limiting what they can do research on particularly with regard to safely. The transnational companies will soon be in a position to dictate the future of the food industry. And they know just how they want our food to be produced – in ways that will maximize their own profits. That means using the gene technology which they have patented and can control, despite the risk of irreversible global consequences for the rest of us.
Some of the food companies are refusing to segregate crops which contain modified genes from those which do not. This makes it impossible to have a proper labeling scheme, which would allow people to make up their minds about weather or not they should eat the products of gene technology. Only a few genetically modified products are on sale in the supermarkets of Great Britain at the moment. Unfortunately, the situation is changing because of the soya bean. Soya beans are grown mainly in North America and find their way into 60% of all processed foods. For example they are in bread, biscuits, baby foods, chocolate, ice cream and many vegetarian products. The inclusion of soya makes it more than likely that people in Britain are already eating modified soya, whether they like it or not. Monsanto , a giant chemical company, modified a soya bean with genetic material from a virus and a petunia linked to a bacterial gene, which has made the soya plant resistant to a weed-killer called Roundup, which is also manufactured by Monsanto. Companies like Monsanto do not spend millions on a new soya bean because it will feed the poor and starving. They believe it will make their shareholders fabulously wealthy. Farmers have to sign restrictive contracts promising to use Monsanto's weed-killers and not grow their own seed. In the race to spread their modified crops all over the world, little attention is being paid to the dangers. Perhaps it is the danger to human health that it most worrying. As our food becomes more and more refined and synthetic, its nutritional value falls, and unexpected health effects are continually surfacing. Some of these do not appear for years, even decades, after the food was eaten. At the same time, unchanged, unprocessed, natural food may actually become more expensive and harder to find. Even when toxins aren't produced, allergies can be triggered unexpectedly. 
There is one more thing that comes into question – is it ethical to move genes around? Introducing genes from bacteria, viruses and even animals into plants raises serious concerns for many people, in particular vegetarians and those with certain religious beliefs.
A huge quantity of disputes and discussions concerning cloning are carried out nowadays. It is well known that the fear of new and unknown things is a peculiar feature of people. People have already forgotten that a few dozens of years ago the world was shocked by the discussion about an opportunity of cloning of a human being. This opportunity has appeared after successful cloning of frogs.