GM and the environment

The last concern about the environment is the most possible, yet also the one with the least reliable data. Possible damage to the environment includes the "spreading" of transplanted genes from GM crops to related wild species, creating "superweeds" with insecticidal properties or herbicide-resistance. These hybrid organisms would then proceed to dominate the environment with their superior characteristics (a la rabbits in Australia or rats in New Zealand). While GM field tests in the UK currently must be sited at least 50 metres from agricultural fields, monitoring exercises have found that both wind and honeybees can carry the pollen up to 20 times these distances (no surprise to anyone with any knowledge of how pollen works).

Another widely-publicised experiment, proving that the pollen of a certain GM crop could be toxic when accidentally eaten by the caterpillars of Monarch butterflies, shows the potential risk to non-pest insects from crops with the insecticide gene. Also scary is the idea that Gm microbes (designed to clean up oil slicks or digest metal ores) could escape into the environment, where they would be virtually impossible to recover. Rather like Pandora's Box. The message: handle with extreme caution. consumers cannot be blamed for being wary.

Advocates of genetic engineering point out that agriculture is inherently damaging to the environment, since forests have to be cleared to make way for farmland. Thus, only if genetic modifications cause greater environmental damage than present farming practices (already horribly polluting) would there be a reason to reject GM crops. Also, some genetic modifications are meant to benefit the environment. For instance, the amount of insecticide used on cotton fields in the USA has fallen by two thirds since the widespread switch to insect-resistant cotton strains. Of course, the problem with GM organisms is that the scale of the potential problems is so great that we cannot afford to be careless.

References:
The Economist, "Food for Thought" 19 June 1999
Geographical, "All in the Genes", Nick Middleton, December 1999

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