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a look at the GM controversy – part one

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a protest against 'zombie crops'

Have been looking at Jack Scanlan’s piece at Panda’s Thumb on the problem of the bad designer for ID, and thinking, while enjoying the piece, how glad I feel about living here in Australia where the ID proponents don’t get to make so much noise and to make the life of bonafide scientists a misery. Here, though, we do have some controversies which I’d like to consider, and one of them is GM food, which, on the face of it, seems to have been accepted so readily in the US, and which seems to have been steadfastly opposed here from the beginning, with virtually no inroads made into our market.

I’ve listened to people getting incredibly aerated about this issue, taking up ‘over my dead body’ and ‘we shall fight them on the beaches’ stances over this assault on the well-being of the biosphere, and I’ve read, in the scientific literature – I mean, in such mags as New Scientist and Cosmos, which is as scientific as I get – that genetically modified food is safe and very valuable, in terms of feeding the world’s population in the future. So it’s time to get sceptical about GM food, though I recognise it’s not an issue that I’ll be able to nail down in one post, or even several.

To give an example of some of the attitudes and arguments over GM foods, here are some quotes from an upmarket cookbook I bought recently, The Urban Cookbook, subtitled cooking and eating for a sustainable future, by Mark Jensen of the Red Lantern restaurant in Surrey Hills. I’ll present the quotes, followed by my commentary:

Scientist have genetically modified the seeds of some vegetables to promote more favourable characteristics. Everything from disease resistance right through to water efficiency is enhanced to ensure maximum yields. These plants all become genetically identical. Some scientists are worried about this lack of gene diversity  and are concerned GM vegetables won’t be able to fight off or adapt to exposure from unexpected pathogens. Our long-term food security will be compromised if we lose the biodiversity that exists today. The increasing promotion of monoculture and GM fruit and vegetables is alarming, and this will be an ever-present concern into the future. Ultimately, all plants and animals depend on their genetic diversity for their long-term survival.

This is the first of five paragraphs Jensen devotes to GM plants. I’ve picked on him mainly because he doesn’t present a hyperbolic anti-GM screed, he comes across as measured and moderate. In the above paragraph he focuses entirely on genetic diversity and monoculture, and claims that the use of GM plants will reduce the first and increase the second. Is this necessarily true?

First it should be noted that there’s GM and then there’s GM. Just about everything we eat has been genetically modified. The history of agriculture is a history of genetic modification, though of course we didn’t know what was going on at the genetic level. When we talk about GM today, though, we’re not talking about the hybridisation [and the reduction of diversity] that has been central to farming and horticulture for centuries. Monoculture has been an essential feature of agriculture since its inception. Modern GM is about the isolation and insertion of particular genes in the lab, for the purpose of promoting resistance to disease, hardiness, nutrients and so forth. This enables monoculture to be taken a step further – instead of monoculture meaning having only one type of crop in your field rather than a variety of types of crops, it can now mean having one genetically altered version of a crop type in your field. It should be remembered that the reason for the rise of monoculture in farming was to feed large populations with a foodstuff that ‘worked’ – a food staple, such as rice, wheat, etc.

Jensen makes the claim that these plants ‘become genetically identical’. In a sense, this is the point. If your aim is to produce a plant that is more water-efficient, then if you succeed, you’ll want to use it en masse, not mixed with varieties that are less water-efficient. In other words GM plants aren’t in themselves responsible for a reduction of diversity, it’s the use to which they’re put. Which might be a bit like saying that guns aren’t in themselves dangerous, it’s just that people use them to shoot each other. It’s a problem – scientists are working on GM plants that provide ‘more bang for your buck’ so to speak; superior, enriched plants that of course are designed to replace ‘inferior’, less nutritious ones. The question is, does the move towards producing these ‘superplants’ en masse reduce genetic diversity in the ‘natural world’, and if so, what does this mean? Will our long-term food security be compromised? Are GM plants less likely to survive ‘exposure to unexpected pathogens’?

The modern form of genetic modification is probably more rightly called genetic engineering, and involves the transfer of a gene from one species to another, so that it can perform its specific function in that other species – generally for the benefit of yet another species, Homo sapiens. The first practical applications were in medicine, in which these methods enabled the production of, inter alia, interferon, human growth hormone and human insulin. Its application to agriculture has enabled the development of a whole sub-field of genetic research, namely transgenic agriculture.

One problem with Jensen’s claims is that he doesn’t distinguish between genetic engineering and traditional plant breeding methods, all of which have been aimed at promoting more favourable characteristics, such as disease resistance and water efficiency. The question then becomes this – is genetic engineering more likely than traditional breeding methods to produce plants that will not survive exposure to unexpected pathogens? The answer, after hundreds of studies, seems to be no. Plants created through transgenic agriculture have to go through rigorous testing before being released into the public sphere, unlike new plants developed through traditional breeding methods. The screening process seems to be working as no problems have arisen as yet with the ingestion of genetically engineered foods. Of course negative claims have been made, both by members of the public and by bonafide scientists, but on further investigation and research, none have stood up to scrutiny. Of course this doesn’t mean that we’ve proven genetically engineered foods to be safe, but nor have we proven that traditionally hybridised plants are safe. In fact we have had problems with old-fashioned breeding methods and the lack of regulation involved in their production, as this story reveals.

Another problem is that monoculture and GM are lumped together, whereas the real problem with monoculture is selective breeding this doesn’t necessarily reduce the genetic diversity of plants in general, it deliberately reduces the genetic diversity of agriculturally grown crops, to maximise yield. A genetically identical crop will be susceptible to be ravaged in toto by a particular pathogen, as occurred with the lumper potatoes planted en masse in Ireland in the nineteenth century, with catastrophic results.

I’ll finish this part with a lengthy quote from the website GMO compass, since they know way more about this stuff than I do:

Producing crops, by its very nature, means getting rid of wild plants on the farm. There are many management strategies used by farmers to reduce the growth of weedy wild plants. If other plants are permitted to grow alongside crops, the crops will have to compete for valuable resources such as light, water, and nutrients. This would have huge negative effects on crop productivity. A certain presence of wild plants on the field, however, can actually be helpful. Wild plants make a more attractive environment for certain animals that are known to deter pests. Well thought-out agricultural practices leave a place for wild plants and still provide crops with good growing conditions.

Agriculture using genetically modified crops must respect this balance. Environmental safety research is conducted to see if traits of genetically modified plants could have a negative impact on biodiversity. Theoretically, there a few ways in which biodiversity could be compromised:

  • Out-crossing: If GM plants pass their new traits on to wild relatives, those relatives could be changed in a way that could make them play a different ecological role, potentially enabling them to out-compete other species.
  • Agricultural practices: Herbicide tolerant GM plants are examined to see how the associated weed management strategies affect the number of wild plants found in fields. Many such studies have been carried out in Great Britain and in Germany. On a case-by-case basis, researchers must determine if specific GM cropping systems lessen or improve biodiversity with relation to conventional crops and see if any differences are of significance.
  • New traits conferred by genetic engineering could offer advantages that could lead to the widespread use of only a few crop varieties – in other words, a loss of cultivar biodiversity. Reducing the diversity of cultivars found in agriculture could lead to problems such as higher susceptibility to widespread outbreaks of plant diseases and pests.

In general, seed companies rarely release only a single cultivar with a new genetically engineered trait; rather, they will introduce the same trait by breeding to many different cultivars. Therefore, using genetically engineered crops doesn’t necessarily mean reducing the diversity of cultivars. It is, nonetheless, a good idea to keep a close eye on this in the long term.

Being aware of the risks is key – as is being aware of the benefits.

Next I’ll look at the second of Jensen’s paragraphs.


Written by stewart henderson

October 31, 2011 at 2:03 pm

Posted in environment

One Response

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  1. […] an argument be made in terms of consequences? Well, I’ve already looked at this, here and here and I can only reiterate that the possible consequences of transgenetic agriculture are no […]

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