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Section E: GMOs – Boon, Bane,
or In Between?
Projected
Outcomes
- Students will know the current role transgenic
varieties play in the principal field crops
of Iowa and Wisconsin.
- Students will become familiar with the major
arguments for and against the use of transgenic
crop varieties.
- Students will be introduced to some of the
politics of science.
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Background
/ Lessons
Introduction
Agriculture began at various places around the
world around 10,000 years ago. Throughout the
past 10,000 years an important feature of agriculture
has been crop selection or breeding. Most of this
selection has been in the hands of individual
farmers, each of whom had slightly different ideas
of what traits he or she wanted, and each of whom
was looking to suit the particular needs of his
or her farm. Farmers traded some seeds and bought
some in times of shortage or to gain new varieties,
but most of the time they saved their own from
the previous year's crop. This process resulted
in an incredibly wide range of crop varieties
in traditional agriculture.
Crop selection and breeding remains an important
part of agriculture, but during the last century
how it is done has changed markedly. Now it is
researchers at universities, special research
stations, and for-profit seed production businesses
who do the crop selection and breeding that supplies
seed for most of the world's staple crops (for
a description of the seed industry in the US see
http://www.ers.usda.gov/publications/aib786/ ). This new system for crop breeding has produced
and disseminated some extremely high-yielding
crop varieties. It has also taken much seed selection
and production out of the control of individual
farmers and has vastly reduced the genetic diversity
of key crops both in the US and around the world.
Also during the past century new techniques for
modifying crops have been developed. The techniques
that have attracted the most attention and the
most controversy allow technicians to take specific
genes from one organism and put them into another
organism.
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Definitions
Biotechnology refers to “any
technique that uses living organisms (or parts
of organisms) to make or modify products, to improve
plants or animals, or to develop microorganisms
for specific uses.” (Definition from the Office
of Technology Assessment, as quoted in Jack Kloppenburg.
1988, First the Seed ) Strictly speaking,
traditional plant breeding and use of naturally-occurring
microorganisms for fermentation are forms of biotechnology.
However, in common usage the term generally applies
to the new technologies of the past few decades,
and in particular to the creation of transgenic
organisms. These two different usages can create
confusion.
Gene transfer or genetic
engineering is the process of taking
a selected gene from one organism and inserting
it into another. Unlike traditional forms of crop
breeding, genetic engineering allows the transfer
of genes across species and even kingdom boundaries.
Transgenic, genetically
engineered, GE, genetically modified organisms,
GMOs, and bioengineered are
all terms that refer to organisms or crops that
have been created by the insertion of a specific
gene from another organism through gene transfer.
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Current
use of GMOs in commercial agriculture
Activity
1. Claims and Counter-claims. Will GMOs Feed the
World or Are They Frankenfoods?
Genetically engineered soybeans were first made
available to farmers in 1996. As the graph below
shows, farmers in the US quickly adopted GE soybeans,
corn, and cotton.
The major GE crops currently in use have been
modified in two different ways:
Herbicide-tolerant (Ht) crops
are engineered so they remain healthy when exposed
to a specific herbicide – in most cases glyphosate
(Roundup). Roundup-ready soybeans are the main
GE crop in Iowa and Wisconsin .
Bt crops are engineered to
produce a variety of the bacterium Bt throughout
the plant. Bt stands for Bacillus thuringensis
. It occurs naturally in the soil and on
plants and can produce a protein that is toxic
to specific groups of insects. The Bt corn currently
in use in Wisconsin and Iowa is toxic to the European
Corn Borer, an occasional pest in this region.
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What
benefits do GE crops provide?
Proponents of GE technology have made sweeping
claims about the benefits these crops can offer.
Let us begin by looking at the crops currently
in use in our states : herbicide-tolerant
soybeans, Bt corn, and herbicide-tolerant corn.
Benefits to consumers
• These crops do not offer any direct
benefits to consumers. Proponents of these crops
claim they are substantially equivalent
to non-engineered varieties, meaning
essentially they are no better and no worse in
nutritional quality. Production costs for GE crops
are roughly the same as those for conventional
crops, and so consumer food prices have not been
affected.
Benefits to the environment
• Reduced pesticide use? GE advocates
say these crops reduce use of pesticides, while
opponents say the claims for pesticide use reduction
have been overstated. See section on “What drawbacks
are there to GE crops” below and “ A Perspective
on Actual Versus Potential Environmental Benefits
of Agricultural Biotechnology” by Chuck Benbrook
at http://www.biotech-info.net/CMB_pew_statement.pdf
for a more detailed discussion of the effect
of GE crops on pesticide use. Overall, the GE
crops used in the Midwest probably have not
resulted in lower pesticide use.
Benefits to farmers
• Convenience. Farmers can use one
product instead of having to decide among a
wide variety of herbicides, each effective on
different types of weeds, and with different
impacts on the crop. Also, farmers can apply
the herbicide at any time without worrying about
damage to the growing crop. With Bt crops farmers
do not have to monitor pest levels and decide
if and when to apply pesticides, and they don't
even have to spray. The pesticide is automatically
produced by the plant.
• Effectiveness. Several weeds have
begun to develop resistance to the types of
herbicides commonly used in soybean production
before the introduction of GE varieties. Glyphosate
(Roundup) had few resistance problems in the
1990s. However, with the heavy reliance on this
product, resistance is starting to emerge.
• Yield increases? (for some crops
some of the time). According to USDA data, Bt
corn has slightly higher yields than conventional
corn varieties on average, while GE soybeans
have slightly lower yields than conventional
varieties. See study by Michael Duffy, Iowa
State University Extension Economist at http://www.leopold.iastate.edu/newsletter/2001-4leoletter/gmo.html
Benefits to Business
Producers of GE seed expect significant profits
from both the seed and from linked herbicide
sales. Whether GE ventures will prove profitable
in the long term is not yet clear. See http://www.biotech-info.net/monsanto_struggles.html
GE crops have also provided a market opportunity
for businesses that test for the presence of
GE genes in crop samples (e.g., http://www.genetic-id.com/
)
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What
are the costs of GE crops?
Risks for Consumers
Basically, the risks GE corn and soybeans may
pose for human health are unknown. Because these
crops are deemed to be substantially equivalent
to conventional crops, their manufacturers have
not had to conduct the types of studies that would
be required to approve new pesticides, drugs,
or food additives. GE seed producers have voluntarily
done some review of their products, but the studies
have not been made public in full.
Americans have been consuming GE crops since
1995, and no human health problems have been documented
from these products. Why does that experience
not prove they are safe?
• Many substances now known to harm
human health (e.g. tobacco, pesticides, heavy
metals) take years to show ill effects – and
don't harm all people exposed. Because GE foods
are not labeled or tracked in the food system,
it will be nearly impossible to trace long-term
health effects back to them in the way public
health researchers have done for tobacco and
pesticides.
• GE products are not all the same.
Small differences in how they are made may change
the risks they pose. For example, in a study
by Cornell University , the pollen from some
varieties of Bt corn was found to kill Monarch
butterflies, while the pollen from other Bt
varieties did not appear to harm the butterflies
that ate it.
Costs to the environment
As with risks for consumers, there is relatively
little concrete information on what the impacts
of GE crops are on the environment. The following
concerns are based in part on experiences with
agricultural pesticides:
• Impacts on non-target organisms.
Crops that have built-in pesticides such as
Bt may affect organisms other than the pest,
including natural predators of the pest species.
For example, pollen from some Bt corn varieties
is toxic to Monarch butterflies. Follow-up research
indicates that in field conditions pollen concentrations
on milkweed leaves (the Monarch's sole food
source) are not typically high enough to harm
them http://www.ars.usda.gov/is/br/btcorn/index.html
. However, possible impacts on a wide range
of other organisms have not been studied, though
one study raises some concerns http://filebox.vt.edu/cals/cses/chagedor/btnontarget.html
. The use of Bt as an insecticide that
is sprayed onto plants has been studied. Bt
sprays are generally deemed environmentally
preferable to standard synthetic pesticides,
partially because they have relatively low toxicity
for mammals and birds and partially because
they break down quickly. However the Bt in GE
crops is present in far higher amounts and because
it is tied up in plant residue it is much more
persistent than sprayed-on Bt.
• Degradation of original crop genotypes.
The behavior of GE organisms in the environment
over the long term is not yet known. There is
some concern that GE traits may be highly competitive
with other genotypes, possibly crowding out
valuable natural genes. Researchers have found
GE genes in corn grown in Oaxaca , Mexico ,
the center of origin for this crop. Because
this region remains the world repository for
most of corn's genetic diversity, production
of GE corn was banned in Mexico . There is a
lot of controversy about how the GE genes reached
Mexico 's corn and how much they threaten the
genetic pool, but the most likely route seems
to be from corn imported from the US , intended
for feeding livestock. http://www.gene.ch/genet/2002/Mar/msg00017.html
• Increased pesticide use?
• The numbers of acres treated with
herbicides does not change with the adoption
of GE crops. What changes is the type of herbicide
used. Glyphosate (commercially know as Roundup,
the main herbicide used with herbicide-resistant
GE crops) is effective at moderate rates, meaning
a switch to Glyphosate may result in a decrease
or increase in total pounds of active ingredient
applied, depending on what product was used
before.
• Due to the development of pest
resistance, any reductions in pesticide use
are likely to be only temporary. A few farmers
are already beginning to find some weed resistance
to glyphosate, and are mixing it with other
pesticides. Some agro-ecologists fear that the
long-term result of GE crops may be the loss
of glyphosate and Bt as effective, relatively
benign pest management tools. GE crop types
developed to date fit into the monoculture-pesticides
framework rather than the Integrated Pest Management-systems
framework.
• Statistics on pesticide use only
monitor pesticides applied externally and ignore
the pesticides generated by the GE plants themselves.
• Overall, there has probably been
no reduction in pesticide use due to the adoption
of GE crops in Iowa and Wisconsin . Virtually
all corn and soybean acres continue to be treated
with herbicides, and corn was rarely treated
for European Corn Borer before the introduction
of Bt varieties. (Bt varieties have reduced
pesticide use on cotton in
parts of the US , China , and Africa . Whether
these reductions will last is another question.)
Activity
2. Modeling Natural Selection
Costs to farmers
• Loss of international markets.
Consumers in the European Union and Japan ,
two of the major export markets for Midwestern
corn and soybeans, do not want GE products.
The US is fighting import restrictions on these
products through institutions regulating international
trade, but their success has been mixed to date.
http://www.globalpolicy.org/socecon/trade/gmos/index.htm http://www.ers.usda.gov/publications/wrs984/wrs984e.pdf
• Problems for organic producers.
Organic standards prohibit the use of GE products
because of the many unknowns about their long-term
ecological and health impacts. Unfortunately,
since corn (and canola) are wind-pollinated
and pollen can travel at least a kilometer under
certain conditions, it is very difficult to
keep the crop free of GE contamination. Organic
farmers can take a variety of steps to reduce
the chance of GE contamination of their crop
(see http://www.organicconsumers.org/Organic/riddleonge012302.cfm
). However, these measures impose extra
costs, either directly, or in the form of additional
labor or yield losses (e.g., from delayed planting
of corn). .
• Development of resistance leading
to loss of useful pesticides (see above)
• Loss of ability to save seed.
Virtually all the corn planted in the US is
hybrid. Hybrid corn has high yields, but the
seed does not produce the desirable characteristics
of the parent plants, so farmers buy new corn
seed every year from specialized seed companies,
and have done so for decades. However, soybean
varieties are not hybrid, so farmers can save
part of their crop from one year to use as seed
the next. But they are not allowed to do so
with GE seed. A number of farmers have had to
pay large penalties for deliberately or inadvertently
planting saved GE seed. http://www.biotech-info.net/nelsons_frustrations.html
, http://deltafarmpress.com/ar/farming_monsanto_dpl_win/
Activity 3: Who Cares About Intellectual Property?
Costs to business
• Organic grain handlers and exporters
have incurred additional costs for testing shipments
for GMOs. In a few cases entire shipments of
organic grains have been rejected due to GE
contamination, leading to financial losses for
organic farmers and handlers
To sum it all up, the only clear benefit from
GE crops in the Midwest to date is the increased
convenience of weed management for some farmers
using herbicide-tolerant soybeans. The only clear
cost to date has been to organic farmers and processors,
whose work has become more difficult, expensive,
and fraught with an extra layer of uncertainty,
and to those farmers who have paid substantial
penalties for allegedly planting saved GE seed.
The other costs and benefits are uncertain, speculative,
or a matter of debate.
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What
about costs and benefits of GMOs in the future?
Here we enter a realm of even more speculation
and uncertainty, and it is difficult, if not impossible,
to fairly and accurately sum up the claims on
either side. The list below provides a tiny sampling
of the range of positions.
Claims and Counterclaims
CLAIM |
DISCUSSION |
Genetic
engineering has the potential to solve world
hunger by producing crops that can overcome
all environmental challenges and deliver
vastly greater nutritional benefits. Only
rich and selfish or completely irrational
people could possibly oppose these important
benefits for humankind.
|
The
world already produces enough food to feed
all the world's people well. The reason
there is hunger is because the food is not
distributed equally. Genetic engineering
will not solve the social causes of hunger
and malnutrition. However, GE might conceivably
solve some localized shortages or help make
some social solutions easier to accomplish.
|
Genetic
engineering could result in sterility of
key agricultural crops, leading to widespread
famine. At a minimum it will put the world's
food supply even more firmly in the hands
of a few mega-corporations. Only blind corporate
greed or completely irrational people could
possibly want to take these risks. |
While
it is true that one strand of GE research
is developing ways to keep crop seeds from
growing without a special release product,
it seems unlikely that this trait would
spread out of control. Also, this is only
one of many avenues of GE research, no organization
has announced plans to apply this “terminator”
technology, and it is probably not in the
interest of either corporations or governments
to cause famine. |
GE
crops can make currently expensive drugs
affordable, curing the sick and enriching
farmers at the same time. |
The
practice of using genetic engineering to
get crops to synthesize costly drugs might
bring down drug costs, but it also poses
very high risks of these drugs getting into
the general food supply. Even during extremely
restricted preliminary field testing of
“pharming” some grain engineered to contain
drugs accidentally got mixed in with the
regular grain supply at the local coop.
Moreover, in most cases what keeps drug
costs high is the cost of development and
testing and the desire for companies to
show a profit, not the actual manufacturing
costs. |
GE
crops will increase poverty and hunger by
making farmers even more dependent on big
business and by favoring rich landowners
at the expense of poor subsistence farmers.
|
Just
as the technology of genetic engineering
will not solve the social problem
of poverty, so it is not the cause
of this social problem. However, it is true
that in the current economic structure,
genetic engineering is closely associated
with business systems that have hurt many
poor farmers. |
GE
crops will eliminate the need for toxic
pesticides. |
So
far, the only GE crop that has resulted
in significant reductions of pesticide use
is Bt cotton, and even for Bt cotton, the
reductions are uneven and unlikely to last.
Integrated pest management (IPM) has more
potential to achieve great and lasting reductions
in pesticide use, but agri-business has
shown little interest in promoting IPM.
|
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Conclusion
At this point, there is not much evidence to
back up either the claims for or against genetic
engineering. Given the large amount of uncertainty,
the debate comes down to one of philosophical
positions.
The position of the proponents of genetic engineering
might be summed up as follows: new technologies
can make life better, and the progress they bring
should not be impeded unless it is proven they
cause harm. Or “nothing ventured, nothing gained”
and “innocent until proven guilty.”
The position of those concerned about the risks
of genetic engineering has been called the precautionary
principle. In brief it states that powerful technologies
have often been accompanied by unanticipated problems;
that the more powerful the technology is, the
greater and more insoluble the problems are likely
to be, and that therefore it makes sense to require
the proponent of a new technology to prove that
it will not cause great harm. Or “look before
you leap.” http://www.biotech-info.net/rachels_586.html
Most of the negotiation about the role of GMOs
is where on the continuum between the two positions
government regulation should be.
This discussion only skims the surface of the
debate about the use of GE crops. Feelings run
high on this topic, and there has been much polarization
and name-calling on both sides, some blatant and
some disguised. Below are very brief summaries
of three areas of controversy.
See http://www.biotech-info.net/
for more information
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