Conservation Biology

Wednesday, August 30, 2006


I was given the subject “genetically modified organisms” (GMO) and how that links with conservation biology. I started off by watching “The Future of Food”, a film by Deborah Koons Garcia, third wife and widow of legendary Grateful Dead lead singer/guitarist Jerry Garcia. This movie certainly wants to bring home the message that there is something sinister behind the whole GM food saga. There are clear villains and heroes in this movie and it sure succeeds in getting your blood pressure up, if you are easily impressionable like me! Besides probably being somewhat one-sided the movie does give the laymen a quick guide through the history of agriculture from the advent of agriculture some 12 000 years ago, through to the green revolution that started with the introduction of fertilizers and insecticides and then eventually by the mid 1990’s the green revolution turning into the gene revolution, when gene splicing made its appearance. Some insights are also given into the whole biotechnology industry and how genes are actually inserted into a cell.

The movie goes on about the health risks of GM foods and the fact that labelling GM products is not required in the USA. This does not allow consumers a choice. Unlike medical biotechnology which takes place in secure laboratories, agriculrural biotechnology produce seeds that can reproduce and once they are put into the environment cannot be controlled. Another worrying trend that is highlighted is the consolidation of food markets and even more worrisome, how big corporations that have links with GMO products have in some way or another “infiltrated” the very government agencies that are responsible for the safety of GMO’s. Sounds like a good conspiracy theory to me!

So, who are the villains in this flick? Well, big companies of course, where money rules and ethics is not part of their vocabulary… and governments, or maybe only certain politicians that are ultimately puppets of the big corporations that put them there in the first place. You have guessed it, the Bush administration (of course!) and Monsanto, one of the biggest (if not THE biggest) agricultural companies of the world. According to the Monsanto website, this is who they say they are: “Monsanto is an agricultural company. We apply innovation and technology to help farmers around the world be successful, produce healthier foods, better animal feeds and more fiber, while also reducing agriculture's impact on our environment.” This is certainly not the picture one gets in Deborah Koons Garcia’s movie. I am not saying that what she has portrayed is right, but even if only a tiny bit of it is true, it just proves once again that money does talk!

Have you ever heard of Round-Up? It is a registered herbicide that kills off almost anything that is green… This seems to have been Monsanto’s trump card in the 1970’s when weeds had become a huge problem for farmers who had moved in the direction of monocultures. Monocultures had produced an ecological vacuum that insects and pathogens as well as weeds could exploit. (Here again one can see that the statement biodiversity equals resilience (Epstein 1997) holds true!!)

A president was set when in 1978 the first live organism, an oil eating microbe was patented in the USA. But the pawpaw really hit the fan when gene splicing came into play. This opened the flood gates and the race was on! Through biotechnology Monsanto produced and patented the first Round-Up-ready seed and soon the company that produced the pesticides and herbicides also produced and sold the seeds. Not a healthy combination I would think. According to Garcia, Monsanto today owns more than 11,000 patents of live organism, many of them seeds that have not been genetically modified!

My intention though was not to try and retell the movie, but rather to look at some of the claims that have been made and see what evidence I could find for either side. Are GM foods safe? Have they been tested well enough? What are the environmental impacts of releasing GM plants into an environment? My search on the net began and instead of finding overwhelming evidence for either side, I found relatively little concrete evidence considering the amount of publicity this topic does enjoy in the news media.

An interesting article by Prakash (2001), The Genetically Modified Crop Debate in the Context of Agricultural Evolution, claims that “no unequivocal evidence of harm to our health or the environment from GM crops” has been documented. Prakash (2001) further argues that societies anxieties over GM products is fuelled amongst others by the lack of reliable information on safeguards that are in place, the constant negative reporting in the news media and a general lack of awareness of how food production has evolved. He argues that food has been manipulated long before GMO’s came into play and never before was the safety of foods questioned. Two wrongs however do not make a right and since this is still a very new field, I do think that scientist should rather err on the side of caution. This is highlighted by Andow and Zwahlen (2006) by admitting that the scientific understanding of the factors affecting the environmental risk of transgenic plants (genetically modified) is still in its infancy.

Three kinds of environmental risks were identified in 1997 by Snow and Morán-Palma. These are (1) non-target and biodiversity risks (including non-target species, ecosystem functions, and effects on soils; (2) risks associated with gene flow and recombination; (3) risks associated with the evolution of resistance in the target organisms, such as insect pests to transgenic Bt crops and weeds to the herbicides applied to transgenic herbicide-tolerant crops. (Bt stands for Bacillus thuringiensis. It is an endospore forming, soil-dwelling bacterium. It contains a gene that produces a protein that is toxic to Leidoptera and Coleptera species. This gene is referred to as the Cry-gene. (Wikipedia contributors. Bacillus thuringiensis))

Many studies claim some potential harm and since this is but a young science, potential harm should not be disregarded. Three studies that have been widely referenced are Losey et al. (1999) that reported on monarch larvae being adversely affected by Bt corn pollen; Hilbeck et al. (1998 a,b) reported a higher mortality rate of immature predatory lacewings (Chrysoperla carnea) when they were fed larvae that had consumed Bt corn; and Quist and Chapela (2001) that reported on traditional maize in Mexico that had been contaminated with GM corn varieties. The first two studies indicate non-target species that could be negatively affected by GM crops and the third indicates a direct threat to the genetic diversity of wild relatives of corn due to gene flow.

I could not find a study that directly links any human health risks to present GM crops. I did however find that there are intergovernmental agencies out there that do monitor GM foods closely. Haslberger (2003) reported that the Codex Alimetarius Commission, a joint FAO (Food and Agriculture Organization of the United Nations) /WHO (World Health Organization) Food Standard Programme has now also included unintended effects of GM foods as part of their health risk assessment. That means that before any GM food can be marketed a case-by-case safety assessment needs to be conducted. This includes the “investigation of direct health effects (toxicity), the tendency to provoke allergic reactions (allergenicity), the specific components thought to have nutritional or toxic properties, the stability of the inserted gene, nutritional effects associated with genetic modification and any unintended effects that could result from the gene insertion. Of particular note, the task force broadens risk assessment to encompass not only health-related effects of the food itself, but also the indirect effects of food on human health (e.g., potential health risks derived from outcrossing)” (Haslberger 2003, p 739).

From what I have read so far, I have to admit that the movie does seem to be one-sided. (But we all thrive on conspiracy theories!!) I am however not convinced that GMO’s hold no danger. My biggest concern is not so much GM foods, but rather the potential devastating effects that GM crops (and soon possibly animals and other plants…) can have on our biodiversity!


Andow DA and Zwahlen C. 2006. Assessing environmental risks of transgenic plants. Ecology Letters 9:196-214.

Epstein PR. 1997. Climate, Ecology, and Human Health. Consequences 3(2): (no pages given). Also available from: [updated 15 November 2004]

Haslberger AG. 2003. Codex guidelines for GM foods include the analysis of unintended effects. Nature Biotechnology 21:739-741.

Hilbeck A, Baumgartner M, Fried PM and Bigler F. 1998a. Effects of transgenic Bacillus thuringiensis corn-fed prey on mortality and development time of immature Chrysoperla carnea (Neuroptera: Chrysopidae). Environmental Entomology 27:480–487.

Hilbeck A, Moar WJ, Pusztai-Carey M, Filippini A and Bigler
F. 1998b. Toxicity of Bacillus thuringiensis Cry1Ab toxin to the predator Chrysoperla carnea. Environmental Entomology 27:1255–1263.

Losey JE, Rayor LS and Carter ME. 1999. Transgenic pollen harms monarch larvae. Nature 399:214.

Prakash CS. 2001. The Genetically Modified Crop Debate in the Context of Agricultural Evolution. Plant Physiology 26:8-15.
(also available online from:

Quist D and Chapela IH. 2001. Transgenic DNA introgressed into traditional maize landraces in Oaxaca, Mexico. Nature 414:541-543.

Snow AA and Morán-Palma, P. (1997). Commercialization of transgenic plants: potential ecological risks. BioScience 47:86–96.

Wikipedia contributors. Bacillus thuringiensis [Internet]. Wikipedia, The Free Encyclopedia; 2006 Aug 11, 16:16 UTC [cited 2006 Aug 30]. Available from:

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Karen Marais
BCB Hons NISL student
University of the Western Cape
Private Bag X17