4.9 - Evaluating GM

Benefits of GM crops

• Genetic engineering puts useful genes into crop plants so farming can produce more food, grow it in places it otherwise couldn't, and make it more nourishing.
• The main benefit is a higher yield - more food from the same area of land.

Higher yield

• Insect resistance - Crops modified to resist insect pests are damaged less, so more of the crop survives. Because the crop protects itself, farmers spray far less pesticide, avoiding harm to non-pest wildlife.
• Herbicide tolerance - Crops made tolerant of a particular weedkiller (herbicide) let a field be sprayed to kill competing weeds without harming the crop, again raising the yield.

Growing in difficult conditions

• Crops can be modified to grow well in difficult conditions - for example to tolerate drought.
• This means food can be produced on land that would otherwise give a poor harvest.

Improved nutrition

• Where people's diets lack a particular nutrient, a crop can be engineered to supply it - for example by adding a vitamin that is otherwise missing.
• This helps prevent the deficiency disease the shortage would cause.

Risks and concerns of GM crops

• There are real concerns about growing genetically modified (GM) crops that people weigh against the benefits.
• The main worries are the escape of transplanted genes, effects on biodiversity and food chains, human health, and long-term uncertainty.

Transplanted genes escaping into the wild

• The most discussed risk is a transplanted gene escaping into the wild.
• If a herbicide-tolerance gene spread from a crop to nearby weeds, it could produce a "superweed" that the weedkiller no longer kills.
• This would make weeds much harder to control.

Effects on biodiversity and food chains

• Growing GM crops may reduce farmland biodiversity.
• If farmers spray weedkiller on a herbicide-tolerant crop, fewer weeds and wild flowers survive, so the insects and other wildlife that depend on those plants decline too.
• This has knock-on effects along food chains.

Human health

• People cannot yet be certain that eating GM food is completely safe.
• Some worry about developing allergies, although there is no clear evidence this is any more likely than with ordinary food.
• The long-term effects on human health are not fully known.

Long-term uncertainty

• Altering an organism's genes might create unforeseen problems that only show up later.
• Because genetic changes are inherited, they could be passed on to future generations.
• For this reason some people argue that more long-term studies are needed before the full risks are known.

Ethics of genetic engineering

• Genetic engineering doesn't just raise practical questions of benefits and risks - it also raises ethical questions about whether it's right to do, not just whether it works.
• People hold a range of views on these questions.

Is it right to modify organisms for human benefit?

• One question is whether it's acceptable to modify living organisms purely for human benefit.
• This concern is sharpest for the genetic engineering of animals, because the modification can cause the animal to suffer.
• Some people argue that causing that suffering for our own ends is wrong.

Worries about the future

• Some people fear genetic engineering won't stop at plants and animals, and might eventually be used to choose the characteristics of human children.
• If only wealthy families could afford this, society might split into those who'd been genetically "improved" and a "genetic underclass" who hadn't - deepening inequality.
• A broader version of the worry is that genetic engineering is irresponsible while so much about its long-term consequences is uncertain - that we shouldn't make permanent, inheritable changes when we can't be sure of the results.

GM and feeding a growing population

• As the population grows, more food must be produced from limited farmland.
• Genetic modification (GM), alongside other biotechnology and improved farming methods, is put forward as one tool that could help meet this rising demand.
• GM is presented as one part of a possible answer - used alongside things like fertilisers and biological control - rather than a complete solution on its own.

The case for GM crops

• Can be engineered to resist pests, raising yields.
• Can be modified to grow better in difficult conditions such as drought, also raising yields.
• Can be made more nourishing where diets are limited.
• Together, these could mean more and better food grown on the available land.

Arguments against GM as the answer

• Hunger is often caused by poverty, not a shortage of food - people go hungry because they can't afford what's available, so tackling poverty may matter more than raising production.
• Dependence on seed companies - Farmers and whole countries could become reliant on the companies that sell GM seed.
• GM can't fix everything - Where crops fail because of poor soil, even a modified crop may not survive.