Genetic Modification

Genetic Modification

The development of genetically modified food is the most controversial

development in farming and the food industry for centuries. Throughout

history man has developed new methods of farming and new types of food

but GM food represents a revolutionary change compared to the

evolutionary process that has ruled up to now.

Scientists have developed methods of manipulating DNA, by transferring

it from one organism to another. Characteristics such as the height to

which wheat grows are encoded into molecules of DNA of all living

things. DNA consists of chromosomes that have series of genes; these

genes are inherited through the generations. A gene that encodes a

desirable trait can be copied and transferred into another organism

and this is called genetic modification. There two main types of GM

crops being grown at the moment. The first can tolerate herbicides

that wipe out other plants and the second type is modified to produce

toxin that kills pest that feed on it.

At present around 25% of the world’s crops are lost to pesticides and

diseases through insect attack which is enough to feed over one

billion people. However with Genetic Modification you can stop this as

for example with the Bt maize, the maize plant modified with poisoning

producing genes taken from the bacterium thuringiensis is able to

resist the corn borer insect which can destroy up to 20% of a crop.

Weeds are also a threat to food crops, even though there is no problem

with the amount of herbicides, there is a limit to when you can use

them. As with ‘broad spectrum’ herbicides you can only spray before

the crop has emerged from the soil and then you spray again with

selective herbicide when the crops start to emerge. However, crops

that have been genetically modified to tolerate the ‘broad spectrum’

herbicide can be sprayed at the optimal time at which to spray and

therefore the fewer sprays can reduce number of tractor trips across

the field and save energy. Since weeds compete for water, sunlight and