Tuesday, August 17, 2010

Traditional Breeding

The term ‘traditional breeding’ usually refers to the process of ‘selective breeding’, which has been used by humans for centuries. As I said in a previous post, selective breeding is basically where you breed two organisms of the same, or very similar, species together in order to create offspring which hopefully will have desirable traits. These can be anything from bigger fruit, brighter flowers, disease or pest resistance, larger leaves... the list goes on and on.

When two organisms mate and produce offspring, the offspring inherit  a random selection of genes from each parent. This means that there is absolutely no guarantee that the desired trait will appear in the offspring. When you breed two organisms together, there is no way for you to control which genes are passed on to and expressed in the offspring. This means that the gene responsible for making larger fruit might not be passed on at all.

It also means that other genes, possibly less desirable ones, can be passed on as well or instead. Even if the correct trait is passed on, there is no way to stop less desirable traits being passed on too. Sure, you could end up with bigger fruit, but they might be bitterer or have a dull colour. There is also no way to stop harmful traits from being passed on, such as high toxin levels. Once these are bred into the organism, you then have to take even more time breeding it back out while still keeping the desirable traits.

Another downfall of selective breeding is the time it takes to get it right. Due to the fact that you are breeding organisms together, you have to wait for them to be in mating season. It can also take a very long time to get the right combination of traits in the offspring – there’s no guarantee that the first generation of offspring will have the desired traits, it could take many generations to get it right.

Many of those who oppose GM question the need for such drastic measures when we already have a working technique to achieve the same end. It is a reasonable argument, however GM has many benefits over traditional breeding, which I will discuss in the next post.

Useful websites:

No comments:

Post a Comment