University of Bristol
Wellcome Trust
Recommended by:
Society of Biology
PEEP for Physics & Ethics at GCSE

Genetically Modified Crops

Differences between conventional plant breeding and GM

Tomatoes from a Greek garden.
Are both of these "natural"?
(Photo: Chrissi Nerantzi)

Natural vs unnatural?

Some opponents of GM crops claim that GM is bad idea because it's “unnatural”. However the distinction between natural and unnatural has been very unclear for a long time.

 What do you understand by the word "natural"? When you look at the British countryside, is it "natural"? Why?

Traditional plant breeding

  • Through cross breeding existing varieties, the breeder aims to re-shuffle the plants' genetic material to produce new varieties that may have useful characteristics.
  • Approx 40% of the genetic material is reorganised in the resulting hybrid plant.
  • From these new plants, the breeder uses a slow process of selection to work out which are useful and which are not.
  • It is a very imprecise technique - thousands of crosses are created to find one or two useful varieties.

Non GM genetic techniques. In the 20th century, new methods of producing genetic variety emerged long before GM technologies were developed. For example, plant breeders often introduce new genetic variation in a crop species by exposing the seeds to gamma radiation or chemicals that cause genetic mutation. Much of the UK’s beer is produced using a mutant variety of barley called Golden Promise that was generated by radiation.

GM technology by contrast, only alters one or two specific genes at a time, which supporters claim leads to far more predictable outcomes than traditional breeding.

 The species barrier

What's your opinion?

Average rating

Current rating: 3/5 (from 2 votes cast)

Read comments

Robert Holland 09-05-11 09:14
NOT RATED Yusuf al-Abdulgasim 25-01-12 11:53
Greetings, my brothers. This very much interests me. I will take this knowledge and fight the fight.
NOT RATED lukas b 13-10-14 15:48
fine for me because we are all going to end up eating it anyway
02-09-16 01:41
[...Comment awaiting moderator's approval...]

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Greenpeace / New Scientist debates
Listen to the following speakers who ask "what do we mean by the word 'natural'?"
(mp3 files)

Audio file: Patrick Holden: we should learn as well as take from from nature.
Audio file: Aubrey Manning: Everything is 'natural'. 
Audio file: Richard Dawkins: We can rise above our destructive tendencies.
Audio file: Chris Leaver:  All food crops, including GM, are the products of human intervention. 
 Website for text versions of the speeches