In this series of articles on genetic engineering, we will be looking at the pros and cons, benefits and dangers of a genetically modified food, genetically modified crop and genetically modified organism. This article focuses on one of the cons.
Background definitions: Genetic engineering (GE), genetic modification (GM) and gene splicing all refer to the process of manipulating genes. Genetic engineering isolates, manipulates (changes/alters the natural gene), and re-introduces the gene into cells or model organisms. A product derived in whole or part from a genetically modified organism (GMO) is a genetically modified food (GM food).
One danger of a genetically modified organism/plant, or a genetically modified crop, is the risk of an "escaped" transgene radically altering nearby ecosystems.
The genetically modified organism might negatively impact the environment:
• If the transgene escapes from the farmer's field into the nearby ecosystem by wind, by insect pollination, or by other transfer.
• Once escaped, if the transgene "breeds" with a wild plant that is similar to it, that transgene could become a part and parcel of the offspring. The offspring would thus be permanently altered from the natural plant. It would be a hybrid.
• The hybridization of the transgenic (genetically modified) plant with non-transgenic (natural) crop plants of the same variety and species could occur.
• Hybridization could occur with wild plants of a species that was of the same genus and closely related, but not even the same species.
• Assuming the population of hybrid plants thrived; they could become so invasive that it could destroy biodiversity and whole ecosystems.
The danger of hybridization with wild plants is only present when a set number of circumstances are in place:
• In order for hybridization to occur, pollen has to reach wild or natural plants from the transgenic plants - so they must be close enough for that to happen.
• If the wild plants and the transgenic plants flower at the same time.
• If the wild plants and transgenic plants are genetically compatible.
• If the transgenic plant and the wild plant produce an offspring (a hybrid), and that hybrid is healthy and fertile.
• Lastly, put them all together to form the perfect scenario for a dangerous recipe that could potentially destroy biodiversity and whole ecosystems.
Farmers are cautioned to prevent wild plants of related species from being close enough for pollination with a genetically modified crop. However, there are documented cases of hybridization with wild plants. Your guess is as good as anyone's on how many undocumented cases of hybridization there are.
Statistics
"In 2003, about 167 million acres (67.7 million hectares) grown by 7 million farmers in 18 countries were planted with transgenic crops, the principal ones being herbicide- and insecticide-resistant soybeans, corn, cotton, and canola. Other crops grown commercially or field-tested are a sweet potato resistant to a virus that could decimate most of the African harvest, rice with increased iron and vitamins that may alleviate chronic malnutrition in Asian countries, and a variety of plants able to survive weather extremes."¹
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¹Human Genome Project website, "What are Genetically Modified (GM) Foods?"
Copyright June 2006 Sally Morton
