Your guide to genetically modified (GM) crops

Genetically modified (GM) crops are plants used in agriculture, the DNA of which has been modified using genetic engineering techniques. This is usually done to introduce a new trait to the plant which it does not naturally possess. For example, the introduction of a drought resistant gene to wheat so that it requires less water to grow.

Since the beginning of cultivation, humans have been selectively breeding plants and animals so that they now resemble those we see around us today. Would it surprise you to know that carrots were originally purple or that cabbage, broccoli, cauliflower, brussels sprouts, collards and kale along with others are all the same species? (Brassica oleracea ) This one plant has been selectively breed over thousands of years, from looking like the image above to now resemble the different vegetables we know today. For example, brussel sprouts are derived from the leaf buds off the stem of the plant. Over time we have bred together the plants which had the biggest and most compact leaf buds on the stem. By only breeding together the selected plants, slowly with each generation these buds became bigger and more pronounced until eventually the plant looks like it does now. Similarly other plants were bred for the other traits which have resulted in the other vegetables.

It is fair to argue that this is a form of genetic modification that we have performed on the plant. Whilst it is possible that Brassica oleracea may have evolved naturally into all the plants we have today it is indeed highly unlikely that it would have without the influence of humans. However, there is little to no controversy regarding the cabbage or cauliflower you find in a supermarket. This then raises the question why is there so much controversy surrounding genetically modified organisms (GMOs), including for the focus of my blog, GM crops?

The answer to this can be found by looking at the advances made by science over the last 40 odd years. We no longer rely just on artificially selecting which plants breed together to give us the desired traits. We’ve now gone a step further with a more direct approach of going into the DNA of the plants and altering it to give us the desired results. Evidently this produces much quicker changes than requiring generation of slowly breeding towards a desired trait and also allows for much more drastic changes to happen. Even those which would previously have been impossible. You could argue that up to 35 years ago (1982) when a tobacco plant became the first artificially altered plant in the world with the introduction of a antibiotic resistant gene, everything we had done is natural but this is no longer the case. Yes there are extreme scenarios where some of what we can now create could be formed naturally through random mutations of genes and extremely specific breeding but the probabilities of such events are so low they might as well be considered impossible. This is where the controversy arises.






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