Question: would geneticaly modified food have an impact on biodeversity?

  1. Good question. It’s very complex, so the answer may not be very satisfying.

    Biodiversity is the range of things that are alive. It’s important that we have a lot of biodiversity because we have a lot of biodiversity – the earth is a reasonably stable system where things feed on other things and populations are kept in check by natural boundaries.

    So if you take out a species, or introduce a new one (suddenly) the consequences can be quite difficult to predict. It’s difficult because the system is so complex. It’s like when you’re playing that game where you throw a bunch of sticks on a table and try to take one away at a time without the whole thing collapsing. You’re never quite sure what taking out one thing will do before you do it.

    Now genetically modified food is different stuff. It may not be a new species, but it’s a new thing, maybe with new abilities. If you release something like that into nature, you’re never sure what will happen. Will it change the feeding habits of an insect, meaning that some bird can’t eat the insect and live? Meaning that that bird species dies out, and some other bird takes over – a bird that’s more aggressive, or smaller, and that will change the feeding habits of whatever eats the bird, and so on. It’s too difficult to predict. Ask your teacher to talk to you about rabbits in Australia as a good example.

    So tests on genetically modified food are done in a very controlled way, usually isolated from nature. Of course we genetically modify things when we select things we want. If we pick only the reddest tomatoes to make new tomatoes, then future tomatoes will become redder. But that is a slow process that exploits nature – what you mean is changing something in the lab to make a completely new thing, and growing that. Then yes, a lot of tests are done to see how the new things grows, does it affect things around it, can it be killed if it gets out of control, those things. There are a lot of people who say the risks are worse than the benefits. There are people who worry about the power of large companies who make the new food who might then control what food could be grown where. This is an argument that’s still going on.

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  2. It’s not really known, which is partly why people are concerned about genetically modified (GM) foods.

    The problem is that you are introducing a new type of plant into a system which is reasonably stable. At the moment the whole circle of life is going round with one thing eating another and being eaten by something else. Everything has a habitat in which it lives, prey which it eats, and predators which eat it. If you change any of these things you might seriously upset the system. If a single species of plant or animal dies out, then it will affect a number of other species.

    GM plants are not a new species, but they are a new version of a species, which has different capabilities. It may need less water to survive, be able to live in a larger range of habitats, or contain an insecticide to kill bugs which try to eat it. This plant has an advantage over the original version, that’s why it was created (usually so that it can produce more food). The GM plant may out-compete the original version and cause it to become extinct. This could then affect the species which ate that plant etc.

    The outcome is really hard to predict though. In the past we’ve used the approach of ‘try it and see’ (introducing rabbits, carp, cane toads) but the approach with GM foods is much more cautious. I think that GM foods will be really important in the quite-near future as the global population is growing and food supplies aren’t keeping up.

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