Genetic Modified Organisms and Humans
Date: Spring 2011
What negative impact, if any, will GMOs (genetically modified
organisms) have on humans and plant health if and when they become
In essence, genetic engineering is an end around some of the
uncertainties associated with traditional breeding. Instead of a
tedious regime of crossing and backcrossing (often with unanticipated
consequences), scientists characterize and isolate genes that code for
desirable agricultural characteristics (i.e. endowing plants with the
ability to make their own selective pesticides, or conferring
herbicide or virus resistance). They then deliver the genes of
interest to a crop through various methods. One method uses the
microbe Agrobacterium tumefaciens (known as nature’s genetic engineer
and the inspiration for modern day molecular methods) as a carrier.
What is potentially worrisome to detractors is the fact that these
introduced genes typically originate from outside of the recipient
crop’s species, or even kingdom! There is concern about any unforeseen
effects that may ensue with these novel genetic cocktails. Of
particular note is that these organisms cannot be recalled once
GMO’s (genetically modified organisms) have been widely cultivated
since 1996. Fears of gene jockeying notwithstanding, no substantiated
cases of harm to the environment or human health have been documented.
However, many argue that the time scales needed to quantify these
effects aren’t yet sufficient.
Potential human health concerns include teratogenicity,
carcinogenicity, allergenicity, and toxicity. Frequently cited
environmental issues include the creation of invasive “superweeds”,
non-target impacts, loss of biodiversity, development of resistance,
and horizontal gene transfer (basically gene promiscuity – organisms
casually picking up genes).
Much of the focus surrounding GMO’s rests with how they are produced
(the methodology) as opposed to the characteristics embodied in the
end product itself (is it actually risky?). Does this amount to unfair
typecasting of GMO’s? Perhaps. Conventional breeding can be quite
imprecise and evidence collateral effects including toxicity, etc.
From an environmental perspective, certain traits such as herbicide
resistance (ALS-inhibitors) have already been developed and
commercialized using selection. These have been released with little
fanfare, despite the fact they embody the same suite of environmental
concerns as their GMO (Roundup Ready) equivalents.
Dr. Tim Durham
Instructor, Office of Curriculum and Instruction
Department of Biological Sciences
Florida Gulf Coast University
I am of the opinion based on my current understanding of the science that there is no impact on health. The issues for me are more about the build up of resistance in the plants to the proteins that could make them less effective over time. I think the fact that these do away with the necessity for spraying fields with many toxic pesticides and herbicides make them safer than conventional farming.
Genetically modified organisms have been produced for millions of years.
Recently, the issue has become politicized so that the issue has become a
political, not a scientific issue.
Example: "Corn" as we know it in the food store is a highly genetically
modified vegetable from the "natural" version, maize. When a farmer puts out
bee colonies to pollinate any number of crops, those crops are being
genetically modified. That's a couple of dozen (hundred?) examples of
genetically modified plants. We do the same with animals.
Many diseases are being brought under control by "genetically modifying" the
invasive parasites, and other microbes.
Who are we to say to a subsistence farmer in Sub-Saharan Africa that he/she
should not plant a seed that doubles, triples, ... , their crop output to
satisfy our affluent "morality" in the Western World.
Address that issue.
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Update: June 2012