This report is about two closely related subjects. One subject is the considerations for and against genetic engineering of our food. This part of the report will quickly reveal my personal bias in favor of engineering, but I have tried to fairly represent the problems as well as the benefits.
The other topic is more important. Genetic engineering gets to the very core of how life works and people are inclined to have very strong feelings about it. Because the public knows so very little about science, some opponents of transgenic agriculture have been able to spread misinformation and manipulate public opinion. As Donna Shalala told a group of scientists, speaking about genetic engineering, ``My concern is if we don't have a broadly educated public ... that charlatans out there will be able to play on public fears.''
Exactly that has happened. Almost everything the general public has been told about genetic engineering of food has originated in the deceptive presentations by skilled propagandists.
Although the science behind genetic engineering is very complex, it is not so difficult for laymen to make reasonable choices with only very basic information.
That doesn't mean that people who possess the same scientific understanding would necessarily make the same choices. Different people have different values. Nothing in this report is meant to demean anyone's value system. I hope to change some minds by presenting accurate information.
This report is a virtual book. I've used hyperlinks in place of footnotes and I've left out most scholarly references. I've tried to make the main flow of the report logical, but since that can be tedious, I recommend following most of the hyperlinks, some of which contain material that's interesting but not vital to the flow. Links which point to a short text will open in a new window, which you may close or move out of the way. Other links open a new page in the main window and you can return to the main text by clicking on ``back''. There's also a clickable table of contents.
I would certainly welcome your
comments at charlesmrader@verizon.net .
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Probably the most important scientific event of the 20th century
was the 1953 discovery, by James Watson and Francis Crick, of
the structure of the DNA molecule which is the basis of
heredity. Darwin had shown how species might have changed over
eons by slow, random natural processes. Watson and Crick gave us
the key to moving evolution along much faster, to suit our own
purposes. (Whether the biological world is governed by God's
plan or Darwin's is a matter which continues to divide people,
but nothing in this report should require you to change your own
view!)
A DNA molecule is like a string of letters, using a four letter
alphabet, easily copied when living cells reproduce. The sequences of
letters make sentences, which we call genes. These sentences are the
instructions for making and operating a living cell. There are two
kinds of sequences. One kind of gene gives a cell the necessary
instructions for making one of the various kinds of protein, used for
structures, enzymes, signals, all the basic mechanisms of life. The
other kind of sequence is used as a control mechanism so that a cell
can tell when to make which proteins and when to do something else.
By 1966, scientists had learned the language of protein-making gene sequences.
This language is the same for all forms of life. That means that
a human gene sentence for making insulin, a kind of protein,
could be transferred to, say, a yeast cell, and then the yeast
cell could equally well make human insulin.
The other gene sequences, the control sequences, are like
switches that turn other genes on or off. A control sequence
could have different results in different organisms, just as an
electrical switch can produce a different result in a car or in
an oil burner. In particular, it could control a completely
different protein-making gene. Some control genes are used to
turn another gene on, and others are used to turn another gene
off, and some control genes turn other control genes on or off.
In a simple case, suppose a cell needs protein A, but not too much.
If the gene that tells the cell to make protein A is turned on, eventually
the control gene will sense that there is lots of protein A available,
so it will turn off the protein making gene. Later when the supply of
protein A has diminished, the control gene will relent and let the
protein making gene turn back on.
There are more complicated control arrangements. For example, the gene
which makes insulin is turned on in pancreas cells but not in
liver cells.
To understand the connection between a gene and its function requires
lots of scientific work, enough to keep biologists busy for a very
long time. Even in the simplest cases, one first needs to know what
sequence of letters make up the protein-making gene, and what
sequences make up the control genes which turn it on or off, as well
as where they are situated on the
chromosome; one needs to know
what signals activate the control genes; then
one needs to know the chemical reactions in which the protein molecule
takes part, and finally one needs to know how those chemical reactions
relate to some activity of the cell. Each different organism has tens
of thousands of different genes and makes a huge number of proteins.
Life is enormously complex.
Slowly but surely, more and more secrets of living things are being
uncovered. Hundreds of genes are now understood completely. There
are many more genes which have been discovered and associated
with some function, but not yet understood very well.
It is now possible to transfer a gene from the DNA of one species to
the DNA of another species. For cases in which scientists know
exactly what a gene does and exactly how it does it, it is now
possible to express that function in another species. That is
genetic engineering.
There are practical applications of this knowledge. The first
practical applications were in medicine, using genetically
modified bacteria to make medical drugs such as interferon,
human growth hormone and human insulin. The second kind of
application was to modify organisms for agricultural purposes.
It is this second application that will occupy us now.
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Rice with Vitamin A
The development of rice with vitamin A was carried out at the
Swiss Federal Institute of Technology, making free use of
patented technology and of the earlier research which had
established the basic facts about how plants synthesize
vitamins. The corporations holding the various patents all
agreed to cost-free use of their patents as long as the rice was
to be provided free to poor third-world farmers. The new rice
strain was then turned over to the International Rice Research
Institute, a non-profit organization based in the Philippines,
where it will be evaluated for its adaptability to various
growing conditions, food safety, and environmental impacts, etc.
The IRRI preserves thousands of varieties of rice with different
genetic characteristics, so the new strain can be cross bred to
produce varieties suitable for almost any locality.
The result is that rural Asians can soon expect to
retain normal eyesight.
Genetic engineers also intend to produce a rice variety rich in iron, because iron-deficiency anemia is a common
problem in the same rural populations. But this is a more difficult problem than increasing rice's vitamin A content. Rice contains a substance called phytate.
Phytate prevents the body from absorbing iron, so it does little good to breed for increased iron content, and the rice plant cannot reproduce without adequate phytate in the grains. Dr. Potrykus hopes to be able to find a gene coding for a protein that will break down phytate when the rice is cooked.
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No-till Agriculture
The world's biggest environmental problem is loss of topsoil to
wind and drainage. The US experienced its dust bowl during the
early part of the 20th century as a result of ploughing up the
prairie. The problem is much worse in tropical soils, which may
have a thin, inches thin, layer of topsoil above a type of
soil which, when ploughed, turns into a non-porous concrete-like
substance. One field, one crop, once. The problem, both in the
prairie and in the tropics, is deep ploughing, which kills weeds
which would otherwise crowd out the desired crop. The solution
is called low-till agriculture. The soil is broken up but not
deeply ploughed. Weeds are killed instead by herbicides. A
herbicide of choice should be cheap, quickly biodegradable and
non-toxic. An excellent choice is a chemical called glyphosate,
except that glyphosate kills the crops as well as the weeds. So
genetic engineers found a gene which lets plants tolerate
glyphosate, and transferred it into soybeans. Today, 63% of
the soybeans grown in the US are glyphosate tolerant, allowing
soil saving no-till agriculture on half the US soybean acreage.
There is another advantage to no-till
agriculture. There are lots of plant residues beneath the
ground, both root systems and humus transported by earthworms.
Ploughing brings this material to the surface, where it can
oxidize. Carbon dioxide is created, a greenhouse gas.
So transgenic soybeans are a positive factor in postponing global
warming. Approximately four tons of carbon dioxide are retained
in the soil per acre per year. This saving is applicable to the
accounting of CO2 reductions in
the Kyoto Treaty on Climate.
In fact, any technology which reduces the need to plough, spray,
or till crops will reduce carbon dioxide emission. Consider a
tractor pulling a ten foot wide harrow over a square mile of
agricultural land. Simple arithmetic shows that the tractor will
travel 528 miles, all the while burning gasoline.
Perhaps you are thinking that even if ploughing has disadvantages,
herbicides don't sound very good either. The very word means ``plant
killer''. But that is not the choice. Traditional soybeans are also
grown using herbicides, most of which are far more toxic than
glyphosate. On the average, the transgenic soybeans actually use 30%
less total herbicide than conventional soybeans. So environmentally,
this is a no-brainer.
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Witchweed Control
Farmers in east Africa are plagued by a devastating parasitic weed called Striga, or witchweed.
Farmers are used to dealing with weeds that grow in the soil alongside the crop and compete for nutrients. From time immemorial, they have dealt with those weeds by pulling them up by hand. Less labor intensive methods like spraying and ploughing are now common. But none of these methods work for the witchweed. Striga attacks plants directly, underground, even before the weed has emerged above the soil surface. It sucks nutrients from the seeds and the roots of the crop. In some parts of Africa, the striga parasite destroys as much as 80% of the crop yield.
But now that a herbicide resistance trait can be transferred to a crop, scientists in Israel and Kenya, working together, have demonstrated a new strategy for striga control.
Before planting the crop, they soak its seeds in a herbicide. The seeds are unharmed, but they become poisonous to the striga parasite. The seed germinates and sprouts without interference. By the time the crop is harvested, the herbicide has decomposed and disappeared.
Their demonstration used herbicide resistant transgenic corn. The same strategy would probably work with Africa's other important grains, sorghum and millet.
Soaking seeds would use far less herbicide than spraying it on the ground, and the complex spraying apparatus would not be needed. This is a significant consideration in Africa, where so many farmers are too poor to own expensive equipment.
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Cheese chymosin from yeasts
Hard cheeses are made from whole milk by adding an enzyme called
chymosin (rennet), which was formerly extracted from the stomachs of
calves, a byproduct of veal. The gene for making chymosin was
transferred from cows to yeast. Yeast can be grown in vats, as
any brewer knows. Although many people consider it wrong to
slaughter calves, yeasts have few defenders. Besides, chymosin
from yeast is cheaper and purer than chymosin from calves. So
today, almost all hard cheese (over 90%) is made from chymosin
produced by genetic engineered yeast.
The poet Omar Khayyam wished for a loaf of bread, a jug of
wine, and thou beside me singing in the wilderness. He owed
two of his three pleasures to the working of yeasts. Today he
would also be indebted to yeasts for a piece of cheese.
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Cotton without Insecticides
Cotton farmers are plagued by various insect pests, such as the
boll budworm, the tobacco budworm, and the pink bollworm. In
the US south, where most of our cotton is raised, these insects
were controlled using chemical insecticides. But there is a
natural insecticide which has been used for almost a century by
organic farmers, a bacterium called
Bacillus thuringiensis, Bt
for short. The bacterium produces a toxin which is deadly to
caterpillars like the three mentioned above, but harmless to
almost everything else (except insects of the order lepidoptera,
butterflies and moths -- even the legendary boll weevil
(Anthromonus grandis) is not harmed by the Bt toxin). So
genetic engineers transferred the gene for Bt toxin from
Bacillus thuringiensis to cotton. Then the cotton plants, which
could make Bt toxin, were cross bred with other varieties in the
old fashioned way. Today, much of the US cotton crop is genetic
engineered for the Bt toxin trait. The use of
chemical insecticides
in the cotton belt has declined dramatically, by over a million liters per
year. Since the Bt toxin is inside the plant instead of
sprayed onto the plant, the only insects which it can harm are
those which eat the plant.
The benefit of reduced spraying of cotton is overwhelming. The
cotton pesticides replaced are extremely damaging to the
environment. They not only kill all insects in a cotton field,
harmless or not, but also nearly anything else in the field,
thus depriving insectivorous birds of their food. There is no
way to keep these pesticides from getting into streams and
rivers, where they are a serious hazard to aquatic life. We may think of cotton as
a natural material, therefore environmentally friendly, but
before there was Bt protected cotton, that was just wrong.
The gene for Bt toxin has been transferred into several other
crops, including potatoes and corn. Approximately 30% of US
corn is now transgenic, and the most popular transgenic
varieties contain the Bt gene. Although we call it a toxin, to humans
and other mammals and birds it's just a nutrient.
The principal potato pests are not caterpillars, but beetles,
and the Bt toxin that protects cotton and corn doesn't harm
beetles. But there is another Bt toxin found in another variety
of Bacillus thuringiensis which is deadly to beetles. The gene
for that toxin was used in potatoes.
Biotechnology also has overzealous advocates who exploit
consumers' fears about pesticides. Except in the case of serious accidents,
there's little to worry about. Our bodies deal with many toxic
substances in many foods, and as long as the amounts are small
enough they give us no problems. The toxic load of pesticide
residues on food is completely negligible in comparison with the
toxins naturally present.
But as they are applied in the field, these agricultural
pesticides are seriously hazardous. Each year many farm workers
are poisoned by exposure to pesticides and farmers have
nightmares about their children or pets being injured by playing
near pesticides. Pesticides can also harm wild birds and small
animals, and when they get into waterways they can kill fish and
other aquatic life. The Bt transgenic plants reduce or eliminate this
danger.
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Slow Ripening Fruits
There are many fruits which ripen after picking.
After they reach optimum ripeness, they begin to deteriorate.
This is necessary for the life cycle of the plant, which relies
on the sweet and pulpy parts to nourish the seeds. A ripe fruit
literally digests itself.
When this process is rapid, it effectively means that the fruit
cannot be enjoyed out of season, or far from its growing area.
For example, there is a popular Malaysian papaya
variety which is unavailable outside Southeast Asia because it ripens
so rapidly that it cannot be shipped very far. But it is quite
easy to genetically engineer a fruit so that it does not ripen
so rapidly. It doesn't even require a gene from another organism.
Instead, a gene involved in the ripening process is copied with the
message in reverse order. So now that plant has two genes with mirror
image structure.
The way an organism uses the information in a gene to make a
protein involves copying the gene (DNA) onto a messenger
molecule, known as messenger RNA. The modified plant copies both
the original gene and the mirror image gene to produce both
types of messenger RNA. But since these messenger RNAs are exact
complements of one another, they can wrap about one another just
like the two strands of DNA, effectively blocking both messages.
This means that the plant makes very little of the enzyme that
causes ripening. This genetic engineering trick is called
``antisense technology''.
The Malaysian papaya was transformed in this way and therefore a
slow ripening variety will soon be available.
The very first genetic engineered plant to be commercially
developed as a whole food was a slow ripening tomato, called FlavR Savr.
It was
developed by Calgene, Inc. Because it could remain on store shelves
for a long time, it could be left on the tomato plant until optimally
ripe, and therefore the FlavR Savr tomatoes sold for a premium
compared to other tomatoes. Although consumers initially liked
Calgene's tomatoes, they didn't ship well and the variety was
eventually dropped.
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Controlled Ripening
A coffee bush ripens a few coffee beans each day for many months. The best quality
beans must be picked just after ripening, so picking coffee beans is very labor
intensive. It would obviously be preferable if the beans would all get ripe at the
same time.
Genetic engineering will make this possible. There is a coffee gene which turns on to
initiate the last stage of ripening. Scientists modified a control gene so that the
ripening gene does not turn on until the plant is sprayed with a triggering substance
(patented and sold by the company that developed the coffee variety). Therefore all
the beans on a bush reach the same not quite ripe stage and stop to wait for the
triggering signal. The farmer decides when to spray the bush so it can be picked
completely clean a few days later.
This can substantially improve the life of the small farmer. He can take a short
vacation without losing part of his livelihood. He can work fewer hours per day, or
he can pick all his crop in a few days and increase his income by working at another
job. A large scale farmer would need fewer workers to pick the same quantity of coffee
beans, and could afford to pay them a higher wage.
The control of when a crop is harvested would be valuable for other crops besides
coffee. For example, the quality of grapes declines rapidly after they reach their
optimum sugar content. Grape farmers now have to mobilize every available hand to
harvest all their crop in a very short time. Their lives would be simpler if they
could spread the harvest effort over a few weeks instead of a few days.
Large scale crops are harvested with special equipment. A farmer would not need to
own a combine if he could rent it for the few days it was needed. But that wouldn't
work if his neighbor needed to rent it for those same few days. If neighboring
farmers could control when their crops become ready for harvest, they could share
scarce and expensive equipment.
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Saving the Banana
Wild bananas have seeds. They reproduce sexually, like beans and oak trees. But
they aren't easy to eat. Bananas grown on plantations have no seeds. They are
reproduced by taking cuttings from older banana plants.
Cultivated bananas are seedless because they have three of each type of chromosome
instead of the normal two of each type. Such plants are called ``triploid''. They are
always sterile. Genetic triploid freaks arise from time to time in nature, but modern
breeders can also use chemicals or electric shocks to create triploid mutant cells.
Bananas have been cultivated for many thousands of years and there are about three
hundred different banana varieties. Each variety was developed by crossbreeding wild
bananas. Whenever a promising variety was been produced, the breeder caused it to be
triploid, hence seedless. That plant was cloned by propagating cuttings, and it became
the parent of its variety. All bananas plants of the same variety are genetically
identical, like identical twins.
Of the three hundred varieties, only one single variety completely dominates
international trade. It is called Cavendish. It is possible that you have never
seen a banana other than a Cavendish banana.
Certain kinds of fungus can infect and kill banana plants. In many parts of the world,
Cavendish banana plants are being attacked by a fungus called black Sigatoka. Since
wild bananas can reproduce sexually, they are not all identical and some wild bananas
can resist black Sigatoka. If the black Sigatoka fungus is present in a region, the
resistant banana types become prevalent. But the Cavendish banana plants have no
resistance. They are all identical so they all die.
To grow bananas commercially, growers must spray their plants with fungicides. Year
after year, the black Sigatoka fungus has been evolving resistance to these fungicides,
so growers have to spray more and more fungicide each year. Approximately one third of
the cost of raising a banana is the cost of spraying it with fungicides, and it gets
more and more costly each year.
A form of black Sigatoka banana disease, now spreading around the world, can
tolerate all known fungicides. Soon it will attack bananas in Central America and
the Carribean islands, the heartland of banana culture. The Cavendish banana will
become virtually extinct. Agronomists estimate that this will happen within ten years.
This is not a fairy tale. It has happened before. Forty years ago, the most popular
variety of banana was one called Gros Michel. But Gros Michel was susceptible to a
fungus called ``race 1 Panama disease''. Now it is gone. Cavendish bananas, which are
not susceptible to race 1 Panama disease, replaced them. (A related fungus, race 4
Panama disease, can infect Cavendish banana plants. At present it is only found in
Malaysia and some nearby countries.) In turn, some other variety of banana could
replace the Cavendish. It would look different and taste different but it would still
be a banana.
There is only one practical way to save the Cavendish banana. It must be given some
combination of genes from wild bananas which are not susceptible to the fungus. But
this can't be done by any natural technique.
Cross-breeding can create other banana varieties because wild bananas reproduce
sexually. But Cavendish bananas reproduce only by cloning. Conventional breeding
would have to rely on rare mutated Cavendish banana plants which can produce seeds
and which can therefore be crossbred, in theory. Even the mutated plants produce
only a tiny number of viable seeds, as few as two or three seeds in a hundred pounds
of bananas. No banana breeding experts think that they can breed fungus resistance
into a Cavendish banana variety in only ten years.
Biotechnology can rescue the Cavendish banana. Scientists in Belgium have used
genetic engineering to transfer some fungal resistance genes from wild bananas. The
transformed Cavendish plants are not susceptible to the fungus and they can then be
reproduced into nursery stock by the usual method of taking cuttings.
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The Eggplant in Winter
The edible part of an eggplant is formed from the ovary of its flower. In this way,
it is like the edible flesh of an apple, a pepper or grape. When we eat these
fruits, we discard the seeds. But the plants only transform their ovaries into
fruits when they start to produce seeds, although in the case of an eggplant,
its seeds are so tiny that we ignore them. Eggplants will only set seeds in warm
weather, so to grow them in the winter in an unheated greenhouse, the grower must
use a chemical to trick the plant into beginning fruit development without setting
seed. Such fruits do not grow very large or very fast under these conditions. So
eggplants are expensive in the winter.
But now scientists in Italy have transferred two genes into a variety of eggplant,
which not only allows the plant to set fruit in cool greenhouse conditions without
chemicals, but also increases productivity of the same plant in either hot or cold weather.
The eggplant variety that the Italian scientists created is seedless. One of
the two transferred genes is a switching gene which is turned on only in the
ovary part of a flower. That gene turns on the other transferred gene, which
makes a protein involved in synthesizing a growth hormone. The growth hormone
makes the ovary grow into the fruit, just as it would have done in a traditional
eggplant making seeds. Neither gene requires either seed setting or warm weather.
Where does one get seeds to produce large numbers of seedless eggplants?
The transformed plants produce pollen, so they can be crossed with traditional
eggplant varieties and the hybrid produced by that crossing has the seedless
and self-starting property.
The scientists report productivity increases of 37% for the new variety,
and they believe that the seedless type would be more marketable.
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Virus Resistant Crops
Some viruses infect people or animals and other viruses infect
plants. Plant viruses reduce the productivity of annual crops and can
kill fruit trees.
Some plant viruses are spread by insects. Plants can be
protected from those viruses by using insecticides or other
pest management methods. There is essentially nothing else that
a farmer can do to protect his crop from virus damage, except to
grow a different crop. But genetic engineering a plant to protect it from a
particular kind of virus is quite easy. A gene from the virus
which encodes a protein in the virus' outer coat is copied into
the plant's DNA. The plant then makes the coat protein, which is
harmless, but which stimulates the plant's natural defenses.
Virus resistance traits have been introduced into many crops,
including squashes, tomatoes, potatoes, tobacco and, perhaps
most dramatically papaya.
Recently, cultivated Hawaiian papayas were hit by a devastating
virus which essentially eradicated the commercial variety. Only
the virus resistant
transgenic papayas survived. If you like papaya, you can
only buy the transgenic variety. Nobody can grow any other
kind.
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The Potato Famine
In 1840s Ireland, the potato crop was devastated by a late
blight fungus (Phytophthora infestans) and Irish people starved
en masse. That fungus could reappear at any time in any place
and wipe out a potato crop. Some varieties of potato have
previously had some resistance to late blight fungus, but now a
fungal strain has appeared in Russia that destroys those
previously resistant varieties. This year (2001) a similar
fungus appeared in potato fields in Prince Edward Island and 630
million pounds of potatoes, the island's principal crop, had to
be destroyed. But very recently, scientists were able to transfer a gene
from alfalfa to a potato plant and the resulting potato plant is
able to resist the fungus and thrive.
Potatoes also rot. A principal cause of potato rot is the bacterium
Erwina carotovora, which has been called the flesh eating bacteria of
the plant kingdom. Now a gene that confers resistance to E. carotovora
has been coupled to a control gene that turns on when a plant has
been wounded, and this construct has been transferred to experimental
potatoes. As the researchers hoped, the modified potatoes, when
punctured by a toothpick and exposed to E. carotovora, had almost twenty
times less rot than unmodified potatoes.
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Sentinel Crops
A recent innovation is a plant intended not for food but for
quality control. It contains a gene derived from a luminescent
jellyfish, but in all other ways it is identical to the food
crop it is planted alongside. When these sentinel plants
experience a lack of water, they literally glow in the dark.
The farmer then knows that his crop must be watered or whether
irrigation can be postponed.
In the western U.S. water is scarce. Agriculture is the biggest
user of water. Wasting water is intolerable. For example, so
much water is taken from the Colorado River for irrigation that
the river flows into Mexico a mere trickle, and it never gets to
the sea at all. So this is yet another way that transgenic
crops can benefit the environment.
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Building with Silk
Silk is composed of two proteins, fibroin and sericin. The
gene for fibroin has been transferred from a
silkworm to a goat, and
is expressed as a component of its milk.
Soon we may also expect sericin to be transferred. It still
remains to be seen whether technology can be developed to spin
these proteins into a fiber.
That has already been accomplished with the kind of silk spiders use
to make their webs. Genes for the two spider silk proteins were transferred
to cells cultured from cow udders. Those cells then made the proteins.
Happily, the spider silk can be spun by forcing a solution of its two
protein components through a tiny nozzle. The proteins self-assemble
into spider silk strands. The same genes have since been transferred
to live goats and when those goats are old enough to produce milk, it
should be possible to make large quantities of spider silk very cheaply.
Silk is an extraordinarily strong material, stronger than steel.
In the future we may be getting our strongest building material
from a farm instead of from a mine.
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Safer Meat
Escherichia coli are friendly bacteria that live in our intestines and
contribute to our health. But there is one strain of E. Coli
(designated as O157:H7) that can make us sick, even kill us. We
can get it from inadequately cooked meat.
The E. coli infected meat comes from cattle with the virulent E. coli
strain in their intestines.
A cow's digestive system is adapted to digesting hay and
grasses. The food first goes into a pre-stomach called a rumen.
That's why cows are called ruminants. In the rumen,
microorganisms turn the indigestible cellulose into nutrients
the cow can assimilate. The food is then passed to a true
stomach, and finally gets to the cow's intestines, where E. coli
can live. Therefore to guarantee against the virulent strain
thriving in the cow's intestine, one needs to get some sort of
prophylactic agent into the intestine.
Antibiotics won't do. They would kill the cow's normal intestinal
bacteria, and besides, it isn't a good idea to overuse antibiotics.
There are antibodies specific to the virulent strain of E. coli, but
they would be destroyed by passage through the cow's stomach before reaching
its intestines.
Genetic engineers are working on a neat solution. They are developing a
transgenic animal feed which resists complete digestion in the stomach and
delivers the antibody, specific to the virulent E. coli strain, into
the intestines.
There are over 60,000 cases of E. coli illness in the United States each
year. There would be many more except for an extensive program
of meat inspection. Even this understates the problem, because meat, if
contaminated, has to be destroyed.
E. coli infections were not such a serious problem when cattle were
raised exclusively on grass and hay. On that diet, there isn't much digestion
going on in the cow's intestine and the E. coli populations are comparatively
low. But today's cattle spend the last weeks of their lives in feed lots,
being fattened up on grain, which is digested in their intestines, leading
to much higher populations of E. coli. So another way to solve the
E. coli problem would be to raise leaner cattle and skip the feed lots.
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Reduced Need for Fertilizers
One of the ways that farmers get better yields is by providing their
plants with sources of organically bound nitrogen and
phosphorus. These can be provided either by applying chemical nitrates
or phosphates, or by using manures or decaying vegetation as sources
of the same nutrients.
Nitrogen is the largest constituent of the atmosphere, about 80%. It
may seem paradoxical that unfertilized plants could suffer from a
nitrogen deficiency while immersed in a sea of nitrogen gas, but it is
just not available in the form they need. Of living things, only
certain bacteria (and human chemists) have evolved the means to
convert nitrogen from the atmosphere to a form useful to plants.
But some plants, primarily legumes (peas and beans), have a
symbiosis with these nitrogen fixing bacteria. The plants provide
nodules on their roots that protect the nitrogen fixing bacteria,
which then enrich the soil around those roots. Not only does this
permit the legumes to grow luxuriantly without nitrate fertilization,
but it makes the soil fertile for other plants growing in the same
soil later. The technique of crop rotation is one of the oldest
techniques of agriculture.
Scientists hope to be able to transfer the genes which direct the
formation of the nodules to other crops. If this is successful, the
need for fertilizers would be dramatically reduced.
Unlike nitrogen, phosphorus is not a constituent of the atmosphere.
There is no short-term likelihood that scientists will find a genetic
engineering way to replace fertilizers that provide phosphates. The best hope
for phosphate replacement would be to breed or engineer plants that make
more efficient use of the phosphate available to them.
If it proves impossible to engineer plants for nitrogen fixation,
there are still options which can let them use fertilizers more
efficiently. An enzyme called glucine dehydrogenase is involved in
utilization of fertilizers. The gene for glucine dehydrogenase is
present in most crops, but it is expressed at low levels, because the
control genes turn it off more than on. A genetic transformation of
wheat which promoted increased synthesis of glucine dehydrogenase was
29% more effective in utilizing the same amount of fertilizer as the
unmodified variety. The increased efficiency can either be used to grow
more crop on the same land, or to cut down on the need for fertilizer
to grow the same amount of crop.
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More From The Sun
Plants derive energy from sunlight and use it to make sugar from carbon dioxide
and water. This is photosynthesis.
Scientists still do not have a complete understanding of how photosynthesis
happens, although they know most of the steps. They know many of the genes which
create the proteins needed for photosynthesis. They also know that there are
differences in photosynthesis from one species to another. It happens that corn
is an overachiever. Corn plants make more sugar per unit of sunlight than any of the
other grains.
An international team of scientists from Japan and from Washington State has
transferred three of corn's photosynthesis genes into a rice plant. Early indications
are that the transformed rice is more productive than the original rice
variety.
A more important potential application may be the development of very fast
growing trees. If global warming cannot be prevented by adding less carbon dioxide
to the atmosphere, by burning less coal and oil, the only
alternative is to depend on processes that remove it. Number one on that list is
growing new trees. Anything that makes agriculture more efficient can make more
land available for growing trees. Anything that makes those trees grow faster
removes more carbon dioxide from the atmosphere.
For many environmentalists, preventing global warming is the highest
priority. But proposed measures to restrict burning fossil fuels have encountered
fierce political resistance. Opponents claim that such restrictions would be
cost too much money, and would cost people their jobs, their comfort and their
prosperity. By contrast, nobody loses anything if carbon dioxide is removed from
the atmosphere by growing
new trees.
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Toxic Soils
Some soils are poor for plant growth because their mineral
content is toxic. A high aluminum content is the most frequent
problem, especially in acidic soils. But it has been possible
to identify a few genes which enable some plants to extract
aluminum compounds from soil and sequester them harmlessly in
their fibrous parts.
Recently, Florida scientists discovered a type
of fern which can
extract arsenic from the soil, although they do not yet know how the fern
does this. But other teams have identified genes that can enable plants to remove
cadmium, zinc and mercury from soils. By transferring such genes to
fast growing plants, it should be possible to clean up some
toxic soils in much the same way as we can use bacteria to clean
up oil spills.
In the nearer term, there is the work of Mexican scientist Luis
Herrera Estrella. He transferred into corn a gene that allows
the plant to overproduce a natural chemical, citric
acid, which it then excretes through the roots. Citric acid binds
to aluminum and prevents the plant from taking it up from the
soil. Herrera's approach is not to extract aluminum from the
soil but to prevent it from passing from the soil to the plant.
A much larger problem is salt-contaminated soil caused by irrigation. Rainwater
is very pure, but
water borrowed from rivers contains some dissolved salt. Over
many years of irrigation, the salt accumulates. But water cannot get from soil
to roots if the soil water is saltier than the intracellular water. In fact,
water goes the other way, from plant to soil, and the plant dies.
A gene was identified in a relative of cabbage. This gene enables the plant
to pump salt from the soil into an isolated part of a cell, called a vacuole,
where it is stored without harm to the plant.
When salt is thus removed from the soil around the roots the plant can
then take up the less salty water. The salt-tolerance gene was experimentally
transferred to a tomato plant, where a control gene keeps it turned on all the
time. The resulting tomato plant is able to grow well in salty
soils. Happily, the fruit is not high in salt, but the plant's stems, leaves and
roots are loaded with salt, so after the growing season the plant parts could be
shipped elsewhere, making the soil become less salty each year. It's one more
case of an environmental problem that can be solved by gene transfer.
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Biological Pest Controls
Farmers, for very obvious reasons, would prefer not to use pesticides.
They cost money and they are dangerous to use. Farmers much prefer
Integrated Pest Management (IPM), a system that combines many different
methods of suppressing crop pests, including encouraging predatory insects.
Farmers even buy them. Agricultural distributors can supply such insects
as ladybugs, praying mantids, lacewings and parasitic wasps.
Integrated pest management includes using pesticides when other means
are insufficient. But when a crop is sprayed with conventional insecticide,
the harmful insects are not the only victims. Predatory insects may also be wiped
out. Without any predators available, the pest populations can recover
quickly, so that a second application of pesticide is required, which
also kills the insect predators.
This vicious cycle could be broken if genetical engineers can develop
predatory insects resistant to common pesticides.
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Rust Resistance
To a plant scientist, rust has nothing to do with oxidized metal. It
is a plant disease caused by a fungus. It blights all the cereal
crops, barley, wheat, oats, corn, millet and sorghum,
but not rice.
The rust fungus reproduces itself by forming club shaped cells called
basidia. Each basidium bears four spores. When the spores are ready,
they are released and carried by the wind. The fungus infecting a
single grain of wheat can easily produce millions of spores. The
spores are so light that they can travel several times around the
world before falling to the ground.
Although some varieties are more resistant to rust than others, no
variety is immune. But rice must contain some combination of genes
that confers immunity to rust. If these genes can be identified and if
their function can be deciphered, it should be possible to transfer
them to other cereal crops and end, once and for all, this most
important cause of famine.
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Fast Growing Trees
Making paper requires large amounts of natural cellulose. Some can be
derived from recycling, but most of our paper is made from freshly cut
trees. The best trees for paper-making are fast growing softwoods with
low resin content, like aspens. Genetic engineers have transferred
genes for pest resistance and herbicide resistance into aspen and have
tinkered with the genetic switches that promote growth to create a
fast growing aspen that could supply our paper needs using
considerably less land.
The paper-making process must bleach out the brown color of lignin,
one of the components of wood. The bleaches used to be dumped in the
nearest rivers, an important and highly visible kind of pollution.
This is no longer allowed, but the disposal of chemicals from paper
mills is still a major headache. At the Michigan Tech University,
researchers have reduced the lignin content of aspen so that fewer
chemicals are needed in the paper making process.
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Fast Growing Fish
Most of the salmon we eat are caught wild, but some are grown in farm ponds. It
takes about three years for a salmon to grow from fingerling size to optimum
marketing size. In wild salmon a control gene turns on the gene for growth
hormone, but only in the pituitary gland and primarily in warm water. So genetic engineers used a different
control gene to turn on a growth hormone gene in cold water. That control gene
was transferred from an ocean pout, and it originally turned on a gene for a protein
that helped the pout tolerate very cold water.
The resulting creature looks and tastes just like the wild type salmon but it
grows three times faster so it ought to be cheaper to produce.
Wild salmon are now under environmental pressure from overfishing
and because many of the streams where they lay their eggs are either
polluted or inaccessible. If farmed salmon can economically replace
more wild salmon, the pressure on this desirable species could
be reduced dramatically.
There's a need for fast growing fish in rice growing regions. Rice is planted
in standing water, but it is harvested from dry ground. With a slow growing rice
farmers often raised fish in the rice paddy alongside the young plants. But newer
strains of rice mature almost twice as fast as traditional varieties. Although this
lets farmers grow more crops per year, unfortunately the rice paddies are not flooded
long enough to raise fish. If genetic engineers were able to make fish grow faster,
the farmers could again exploit this valuable protein resource.
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Consumer Traits
Most of the traits in the examples mentioned so far have been
targeted at the producer. The no-till soybeans are cheaper to
grow because ploughing costs money. The cotton is cheaper to
grow because chemicals cost money. The chymosin from yeast is
cheaper than chymosin from calves. The consumer doesn't know
how much water or fertilizer the farmer used, or whether a salmon
is one year old or three. The vitamin enriched rice is
the only one of the examples where the final product is
better, rather than cheaper, for the person who eats it.
But in the future we can expect to see ``consumer traits''. One
of the first to appear will be potatoes genetically engineered
to have a higher percentage of solids. If you love french fried
potatoes but don't like the calories, you will love the new
potatoes. They will absorb less oil but stay crispier longer.
Another valuable trait coming soon is coffee beans without
caffeine. Caffeine is now removed from coffee by a chemical treatment,
invented by German chemist Ludwig Roselius. Decaf is the only coffee I drink
so I am looking forward to cheaper decaf coffee.
In addition, many common foods are not safe for everyone. For example,
peanuts cause a life threatening allergy in some people, especially
children. Allergens are
unusual proteins which are digested very slowly. Someone who has an
allergy to a widely used food needs to read the small print on product
labels, quiz the waiter in a restaurant, etc. If a child has the
allergy, the problem is that much harder to manage. But peanuts or
other crops are now being genetically engineered to eliminate these
allergens. USDA scientists have identified the principal allergen in
soybeans and have successfully developed modified soybeans which do
not produce that allergen.
It is much easier to deactivate a gene, once its function is
discovered, than it is to transfer a gene from one organism to
another. The same antisense trick that was used to delay
ripening can be used to suppress synthesis of an allergen.
Therefore, once a gene has been identified which codes for an
allergenic protein, the technology to eliminate that allergen
from food crops is relatively easy, unless the allergenic
protein is important to the life processes of the plant.
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Lawns That Don't Need Frequent Mowing
In addition to food and fiber, genetic engineers are working to
modify grass. Farmland constitutes mankind's biggest footprint
on the earth, but lawns, athletic fields, golf courses, etc.
have the biggest footprint in some communities.
Environmentalists have many criticisms of lawns. They must be
mowed regularly, which uses gasoline, creates noise pollution,
and takes up people's time. In addition, the growing grass uses a very
significant amount of water, fertilizers and pesticides, to make
longer leaves which are then cut off by the mower.
But genetic engineers are trying to develop a variety of grass which
reaches a desired length and then dramatically slows its
growth. Combined with pest resistance genes, this new grass would be
almost as simple to maintain as astroturf.
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What Can't be Genetically Engineered?
It takes only your imagination to come up with other possible
applications of genetic engineering in agriculture. I like to
joke about scientists developing a vegetable which grows its own
bar code.
But nothing can be accomplished until scientists
have identified the relevant genes, figured out what they do,
and figured out how the proteins they make work in the organism.
This point is vitally important. For example, scientists at one
company tried to make a blue rose. They transferred the gene
for delphinin, the blue pigment in delphiniums, into a rose
and the rose made delphinin. But its flowers weren't blue. The
scientists didn't understand how a delphinium uses its pigment,
or how it would be used in a rose.
There are virtually identical
genes in flies and humans, but they have profoundly different
results. Until scientists understand each step of some life
process in one organism, they will never successfully transfer
the trait to another organism. The only successes
achieved so far have involved either a single gene or a group
of closely related genes whose function has been worked out in
detail. Some characteristics, such as humans' height, are affected by
at least dozens of genes, some of which surely affect other
attributes. We are very far from being able to genetically engineer
complex traits.
Unlike traditional plant and animal breeding, genetic engineering is
not hit-or-miss. Genetic engineers do not have perfect control
over the transferred genes, but they have much more control than the
traditional breeders have.
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Legitimate Concerns about Transgenic Agriculture
There are problems with genetic engineering. As an engineer myself,
even though I work with electronics instead of genes, I am naturally
disposed to be sympathetic to genetic engineering, but that doesn't
mean that it should be practiced without a concern for its
dangers.
So the next part of this report is devoted to a survey of some
of the legitimate concerns about genetic engineering of crops.
Later we will mention some other concerns that are not
realistic at all.
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Monkeying with Mother Nature
Some people think that this is an enterprise that should be left
to God or to Mother Nature, that man was never intended to
monkey around with other species' genes. I respect this
point of view, even though I don't agree with it. But it can't
be the basis of an argument. Whoever claims to know what God
intends usually can't prove it, and can't be talked out of
it.
Some people have religious or ethical concerns. They might
point to Leviticus
19:19, which prohibits crossbreeding. Vegetarians may
reasonably decide that their food should not contain genes derived from
animals. Jews and Muslims may reasonably decide that their food must
not contain any genes derived from a pig.
Some religious scholars believe that a gene loses its identity
when it is copied and the copy is inserted into a target
species. That point of view would remove some, but not all, of
the religious objections to genetically modified plants.
Other advances in biotechnology have drawn most of the attention of
clerics and ethicists. These include cloning, organ transplantation,
research using foetal tissue, etc.
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Food Safety
Crops modified in any way might not be safe to eat, so any major
change in the food supply should be tested. This applies to
changes made by genetic engineering but it ought logically to
apply even more to changes made by other techniques. To a great
extent, genetic engineers know what they are doing. There can be
unanticipated consequences, but by comparison, all other methods
of improving crops involve an element of luck. The conservative
approach is to test all crops whose genetics has been modified
in any significant way.
An example of a possible safety issue was brought out clearly
several years ago. Although soybeans are a good source of protein,
soy protein is low quality. It doesn't have enough of the
essential amino acid methionine. So scientists in
Nebraska planned to transfer a gene from a Brazil nut to a soybean
to get better quality protein from soybeans for use as an animal
feed. Unfortunately, some people are allergic to Brazil nuts and
it turned out that the better quality protein was one of the Brazil nut
allergens. Since this fact was quickly revealed by testing, the
genetic modification project was abandoned. This example shows
that testing for safety is necessary. It also shows that such
testing is being done and is working. But can new foods ever be
tested enough for complete assurance of safety?
Another way to develop crops with new traits is to cause random
gene mutations and select for them. This is analogous to spraying ink
on the pages of a recipe book to make it hard to read, then following the distorted recipes to see which work well, and recopying those recipes. Breeders have induced
mutations using radiation, chemicals and high temperatures. Since the
effect of mutation is random, it makes sense that crops
developed by mutation ought to be even more thoroughly tested
than crops developed by genetic engineers since the genetic
engineers are not relying on luck to get their improved traits.
Yet there is essentially
no regulatory process for plant breeding in the United States,
although Canada requires that all new types of cultivars be tested.
Even conventional breeding techniques can accidentally create
harmful foods. In a famous example, an improved variety of
celery caused farm workers who picked the celery to become
hypersensitive to
sunlight. In another example a potato variety, Lenape, was
withdrawn from the U.S. market in the 1960s when it was found to
contain dangerously high levels of potato toxins (solanidine
glycosides).
Even without mutations, there is a large pool of genetic variability
in every variety or species. This means that unfavorable combinations
are possible. In every instance of sexual reproduction the child gets
some genes from each parent, in a random assortment. If John and Jane
have a few hundred different genes (and about 30,000 that are
identical), their children will each inherit a different subset of
John's genes and a different subset of Jane's genes. Nobody can
predict the characteristics each child will inherit from its
parents. Sometimes, two apparently healthy parents have a child with a
genetic disease. Similarly, sometimes two plants which bear nutritious
food can have offspring which are more toxic. This is not an argument
against having children or against breeding crops, so it ought not to
be an argument against transferring genes by biotechnology.
Conditions of growth can also affect food properties. Certain
inconspicuous fungi can turn a wholesome food into a poisonous
food. Every year there are deaths from ergot, a fungus that
infects wheat and rye, and from aflatoxin, caused by a mold that infects
peanuts and corn.
In summary, genetic engineered crops need to be tested for safety. In
the US, transgenic crops are tested much more strictly than crops
developed by traditional breeding. So far the testing that has been
carried out has been sufficient to protect the public. During the ten
years that we have been eating transgenic foods, nobody has ever been
exposed to unsafe genetic engineered food. Meanwhile there have been
many thousands of deaths because of unsafe conventional food. So it
seems to me that the issues of food safety are being better managed
for genetic engineered foods than for conventional foods.
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Environmental Concerns
The third thread of concern is for the wild environment. Suppose
a gene from an unrelated species is transferred to a crop
species and then the modified crop produces pollen which
fertilizes a wild plant. Or suppose some of the crop's seeds are
carried by birds or by wind into the wild. The wild plant could
reproduce and the gene could become fixed in the wild
population. If it conferred an advantage, a wild plant that had
been barely making it in the struggle for existence could turn
into a dominant species. There are many examples of plants
taking over an environment. Usually they are natural plants
introduced from a distant continent. In the American south,
kudzu is a decorative plant that escaped and is spreading out of
control. In the northeast we see the same thing happening in
marshes, being taken over by purple loosestrife. Pasture land in
the American west is being invaded by cheat grass. These plants
have no natural enemies and can overrun an ecology and devastate
it.
So suppose a genetic engineered crop has been given a gene which
makes it hardier. Suppose it gives the plant a tolerance to
salty soil, or to cold, or to dryness. It is reasonable to fear
that if the crop's pollen fertilizes a wild relative, that
relative could produce a race of super weeds.
The solution to this concern is, again, testing. Scientists
must study the plants growing wild in the area, determine which
are closely related to the modified crop, experiment to see if
hybridization is possible, and require that the crop be grown
only in conditions for which hybridization is very unlikely. Or
else, determine that the trait, in the wild relative, will not
matter much.
Sometimes this is fairly easy. You can be pretty sure that
soybeans will not hybridize with wild relatives because they
self-pollinate and because the wild relatives live only in Asia.
Corn can only hybridize with its wild relative, teosinte, found
only in Guatemala and southern Mexico. Sugar beets are harvested
before they produce flowers (unless they are being grown for seed)
so they cannot pollinate other varieties. But for some other crops
the testing should be much more extensive and in some cases it
will not be allowable to grow the genetically modified crop in
localities where wild close relatives are found.
Earlier we mentioned a variety of corn which could grow well in
soils with high levels of aluminum. That variety was developed
in Mexico, but cannot be field-tested there, perhaps because of
the fear that it could pollinate its relative, teosinte, and
give teosinte an advantage over other local wild plants. If
careful analysis confirms this danger, there might still be a
way around the problem. It is now possible to produce plants
which are male-sterile. They produce no pollen, or only
defective pollen. A farmer could then plant conventional corn
as a pollen source and aluminum tolerant corn for his main crop.
Since the plant with the extra gene is infertile, it would not
be able to spread its gene by pollination. This still leaves the
possibility that a seed could escape, carrying the special gene,
but corn cannot live at all as a wild plant -- it cannot reseed
itself -- so this avenue of gene transmission is much less
likely.
Transgenic salmon have been engineered to grow faster than their
wild relatives. There is a concern that they might escape from
confinement pens and reproduce, or even cross with their wild
relatives. Nobody can confidently predict the ecological effect
of this. The transgenics could monopolize the wild salmon's food
supply or be preferred as mates. If they were effective at
attracting mates but less prolific breeders, salmon populations
could crash. To prevent all these possibilities, Aqua Bounty
Inc., the company developing transgenic salmon, plans to use
only sterile females in commercial production.
Not every species that escapes into the wild will be a problem.
Most crops will simply die out because they can't compete with hardier
wild plants. In one experiment, rapeseed plants, both transgenic
and conventional, were grown in a field but never harvested. Scientists
then followed the subsequent history of the field for ten years.
All the crops declined in numbers from year to year. After the fifth
year, none of the genetically modified crops could be found at
all, and after ten years there were only a few crop plants of
any type remaining in the field.
In a more colorful example, during the nineteenth century, a
wealthy and eccentric man brought to the United States
populations of each type of bird mentioned in the works of
Shakespeare. Only one species was able to establish itself. That
species, however, was the starling, now found in large numbers
in every part of the United States.
Some species out of their natural place can enrich the
environment. The European honey bee (Apis mellifera) was
introduced to America in colonial times. Besides its value as
a honey maker, it is the principal agent of pollination for many
staple crops, which are also
European imports.
Organic farmers have a different concern. They consider a genetic
engineered crop to be automatically non-organic even if it is
grown without pesticides or chemical fertilizers. They have expressed
the concern that their crops
might be cross fertilized by pollen from a gene modified crop
. Organic farmers have every right to be protected from this
problem. It is no different, in principle, from the problem faced by
the seed companies who grow seed for sale. It is solved partly by
keeping the different crops far apart, and partly by more active
techniques, like barriers.
There is another concern. Suppose a crop is developed which is
resistant to a certain insect or fungus. Evolution is like an
arms race. Insects or fungi can evolve to overcome whatever
defense has been built into the crop. For example, cotton with
the Bacillus thuringiensis toxin will eventually lead to insects
evolving a resistance to Bt toxin. But Bt is used by organic
growers to control certain insects. I've used it myself. If boll
budworms evolve Bt resistance, organic cotton farmers will not
have alternative controls. Non-organic farmers might turn to
some other insecticide, but even they would like some strategy
to delay the evolution of resistant
insects.
The solution to this problem is the so-called refuge strategy.
Instead of growing only Bt cotton in a large field, the farmer
must grow a mixture of Bt cotton and conventional cotton. This
is an EPA rule. The theory is that then the insect with a lucky
mutation who can tolerate the Bt toxin will have no advantage
over the other insects without the mutation so Darwinian
selection will not tend to increase the numbers of such insects
in a population. This strategy is not simple. What percentage
of the cotton in a field must be conventional, and how must the
two types of plants be spaced? What about how the field is used
in the following season? Personally I am not enthusiastic about
the refuge strategy, but so far it has worked as advertised.
Yet, as more and more acres are sown with Bt crops, year after
year, it seems as if the insects must eventually evolve the
resistance. In the same way, some weeds will eventually evolve a tolerance
for any widely used herbicide.
Eventually genetic engineers will develop better ways to delay the evolution of
insect resistance. Many plants have natural insect defenses which they use only
when they are being attacked. Today's Bt crops express their toxin all the
time, which gives their insect adversaries a constant environment in which to
evolve. It would be much harder for insects to evolve a resistance to a varying
environment. So it would be better to control the gene for Bt toxin
selectively. For example, if scientists could identify a control gene that
turns on when the plant is attacked, they could use an an identical copy of
that control gene to turn on the Bt toxin gene only when it was needed. Even
easier, a control gene could be used which would turn on the toxin gene in
response to a cheap and harmless chemical which the farmer would spray only when
deemed necessary.
The problem of evolved resistance is not new to genetic
engineered crops. Insects also evolve resistance to chemical pesticides and to
other control methods. Some farmers used to protect corn from rootworms (beetles)
by growing corn in a field used every other year for soybeans. The corn rootworms
soon evolved the habit of laying their eggs in soybean fields. Farmers and agricultural
scientists are unlikely to ever find a perpetual solution to suppressing insect pests.
One widely voiced concern about transgenic crops is quite ridiculous, the fear that
they could transfer unwanted genes to the bacteria that live in our intestines.
Many genetic engineered crops contain a gene for resistance to an antibiotic,
such as kanamycin, which was transferred along with the useful genes. The reason is that
most genetic transfer attempts are unsuccessful in some way so the genetic engineers try to transfer the useful genes into hundreds of plant cells at once, hoping that a few cells will be successfully transformed. But after a gene has been transferred into a plant cell, it takes much hard work to create a whole mature plant from that single cell and the genetic engineers want to avoid that work except for the cells that have been transformed. But it is hard to tell when a gene transfer has worked if the gene only functions in the mature plant. The antibiotic resistance gene acts as a marker. When the
transformed cells are treated with the antibiotic they survive, but cells that
were not transformed die. Only the marked cells are turned into mature plants for further experimentation.
But the concern has been voiced that E. coli bacteria which live
in our intestines could obtain these genes and become antibiotic
resistant. We certainly don't want that to happen, at least not
by accident.
We can't transfer genes by eating them, but, unfortunately,
bacteria can take
up DNA from their environment and incorporate it in their
genome, although this phenomenon is extremely rare. It is
billions of times more likely for bacteria to acquire a gene
for antibiotic resistance by natural mutation. Each of us has a
few such bacteria in our intestines now. That's where the marker
genes originally came from. If we are not taking the antibiotic
medicine, the percentage of these bacteria will be quite
negligible. The only defence against both the natural evolution
of antibiotic resistance and the circuitous route through transgenic crops
is to minimize the use of antibiotics.
Nevertheless, although the best scientific evidence is that antibiotic
resistance genes would not be a problem, genetic engineers have stopped using
them as marker genes. The alternative marker gene now favored confers resistance to
a herbicide instead of resistance to an antibiotic. Another kind of marker gene comes from a bioluminescent jellyfish. It promotes synthesis of a fluorescent protein. When
this protein is exposed to ultraviolet light, it produces visible green light,
clearly indicating that the desired gene has been transferred to the target
organism. Also, after a genetic engineer has created a useful new variety of plant with both useful genes and marker genes it is possible to eliminate the marker genes from future generations of the plant using conventional cross-breeding.
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Economic and Social Concerns
There is one last concern often expressed. Although the
gene transfer technology is available worldwide, some people
worry that a few large companies would get control of world
agriculture, and further, that small farmers in the poorer
countries would be at an ever increasing disadvantage as their
competition becomes ever more productive. The counter-argument
for the first concern is that we already have antitrust laws in
place. The counter argument for the second concern is that the
poor third-world farmers could also adopt more efficient farming
practices. The experience of the last thirty years, the
so-called green revolution for which Norman Borlaug received his
Nobel Peace prize (1970), is that third world farmers can and do adopt new
technologies. However, genetic engineering is yet one more
technology which is making agriculture more dependent on large
companies.
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A Debt to Critics
The two most serious concerns about transgenic agriculture are
food safety and environmental impact. So far the record of the technology
has been enviable. There have been no documented cases of any illness or any
environmental damage.
For this the scientists developing the technology must and do owe a debt of
gratitude to the people who have raised doubts. Responsible critics have
suggested problems and the scientists have been able to take
appropriate precautions, or have cancelled dangerous experiments.
The anticipated mishaps didn't happen because they were anticipated.
For example, if no critic had raised the possibility of allergies, would
transgenic foods be tested for known or likely allergens? If no critic had
raised the possibility of insects evolving resistance to Bacillus
thuringiensis, would the Bt cotton be grown with non-transgenic cotton close
by? Would transgenic salmon farming be limited to sterile females if no critic
had raised the possibility of escape and crossbreeding with wild stocks?
It takes no credit away from the scientists to acknowledge that the enviable
safety record of genetic engineering in agriculture derives as much from its
critics as from its inventors.
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Part II
The previous discussion has shown us that there is a new
technology, proven to deliver advantages to farmer, consumer, and the
environment but that there are reasons to be concerned because, like
any new technology, it could be misused. Since the US has been the
leader in adopting genetic engineering for agriculture, our government
agencies have developed some standards for assuring food safety and
environmental safety. Any genetic engineered product must meet these
standards before it can be grown commercially.
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The Moratorium / Ethics of Genetic Researchers
I would like to mention something of the history of this
research. During the 1970's, without any government regulation
whatsoever, all the researchers in the field of genetic
engineering adopted a self-imposed moratorium on further
research for one year. They spent that year in developing and
agreeing to a set of standards for experimental work to assure
that the public would be protected from danger. To the best of
my knowledge this is the only example of its kind in the history
of technology.
At the beginning of the public funding of the human genome project,
it was the scientists, not the politicians, who decided to devote
five percent of the funding to a study of its legal, ethical and
social implications.
These events show that concerns for safety and for the social
consequences of their research were on the minds of genetic
engineers from the beginnings of their field, and that they
have, as a group, exceptional ethics. Now we shall see examples
of the ethics of some opponents of transgenic agriculture.
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A Movement to Frustrate Transgenic Agriculture
Although there are legitimate reasons to oppose genetic
engineered agriculture, or at least to demand the most careful
controls, there are a community of opponents who have
taken their opposition beyond what is ethical. I am not talking
about a reasonable opposition expressing the concerns summarized
earlier, but rather about an opposition for which the ends
justify the means, including lies, vandalism, etc.
I need to stress this point. There are many people, sincerely
opposed to genetic engineered crops, whose ethics I do not
question. I believe that most of the opponents of biotechnology
would fall into that category. Yet, in too many cases, those sincere
concerns are based entirely on misinformation which originated in
deliberate lies and fear mongering. We are here exposing the
ethics of the people who have created the lies.
These opponents must have some motive, and it seems that an
alliance has emerged between at least four groups, each with its
own agenda.
First there are people who sincerely believe that genetic
engineering is ethically wrong, and that anything they do to
stop it from happening is therefore right.
Second there are foreign governments and their constituencies
who are worried about American domination of agriculture. Closely
related to this are advocates of organic agriculture who seem
to be engendering public fear to make their own products
more salable.
Third, there are environmental groups who have been misled by a
radical fringe and have become willing to do anything to stop
genetic engineering agriculture. The most conspicuous among
these groups is Greenpeace.
Finally, there are people opposed to capitalism or to large
businesses dominating agriculture.
Opposition from environmental groups is particularly frustrating
to me. Most measures which benefit the environment require
people to give up something, and they don't like to do that.
Recycling is nearly painless and saves money, but many
people won't make the effort. A few degrees adjustment of
a thermostat could save vast amounts of energy, but most people
would rather be comfortable. We end up settling for half
measures. But here is a technology that benefits the environment
without asking people to give up anything, and its biggest
opposition comes from environmental groups.
Now let us visit some examples of deliberate mischief.
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Misinformation about Food Safety
There is a deliberate campaign to frighten people about the
safety of the food supply. This campaign has worked successfully
in England and in much of Europe.
Dr. Arpad Pusztai, who worked at the Rowett Institute in
Aberdeen, Scotland, performed an experiment. It began when a gene
was transferred from a poisonous plant, the snowdrop, into a
potato. The transferred gene specifies the production of a
poisonous compound called
lectin. Dr. Pusztai proceeded to experiment with rats. Some
rats were fed with the raw potatoes which were genetically
engineered to contain the poison. The rats in the control group
were fed ordinary raw potatoes and were also given the amount of
lectin poison which the first group of rats would have gotten
from eating the transgenic potatoes. Both groups of rats
developed malformed organs, and there was no statistically
significant difference between the rats who consumed the
poisonous potatoes and those who consumed the poison.
However, Dr. Pusztai claimed that his data showed that the rats
who ate the genetically modified potatoes had more deformed
organs. No scientific journal would publish Dr. Pusztai's
interpretation, and his institution would not support him. He
hired an independent statistician to review his data, who also
considered the data to show no difference between the two
groups. But Dr. Puzstai held to his opinion. Eventually the
disagreement became serious enough that his connection with the
Rowett Institute was ended.
The opponents of genetic engineering, mostly in England, have
blown this result into a cause celebre. Dr. Pusztai is portrayed
as muzzled by the scientific establishment, although the British
medical journal Lancet eventually published Pusztai's paper over
the recommendations of its reviewers because of the widespread
public interest. The British tabloid press covers this story
continuously, with lurid photographs of deformed rat organs.
The potatoes genetically engineered to be poisonous became
synonymous with all transgenic food, called Frankenstein food in
the tabloids.
There are varieties of potatoes, bred to be eaten,
engineered to resist insects, viruses and fungi. All these
varieties have been fed to rats and have never harmed them. The
opponents of transgenic food have no explanation for that - they
are content to use one probably misinterpreted experiment with
potatoes nobody will ever eat, to stir up doubts about food safety.
During safety testing of transgenic tomatoes, Dr. Belinda Martineau
discovered that when rats are fed huge amounts of tomato paste they can
develop stomach lesions. It doesn't matter whether the tomatoes
are transgenic or not. But before there were transgenic tomatoes, nobody
had ever fed rats such large doses. Martineau's results were
reported to the FDA and published, but opponents routinely call this
a ``cover-up'' of a health hazard with transgenic tomatoes.
As another example, I read an op-ed article in the Boston Globe
in August of 1999, written by Paul Billings, a member of
the board of the Council for Responsible Genetics. The gist of
the article is that dangerous untested foods are being foisted
upon an unsuspecting American public, by mad scientists. As we
have seen, this is at least an exaggeration. Every genetically
engineered crop has been
tested for safety. The testing has been much more extensive
than that for any other foods, including foods developed by
radiation induced mutation. Dr. Billings knows this. He knows
about the government testing rules that establish the safety of
each individual crop. He wants genetically modified food to be tested
as strictly as drugs are tested.
Billings' op-ed article contains only one `fact' that most
people would not have known before - the rest is
either his opinion or just wrong. He says that transgenic
soybeans have been shown to be deficient in a certain
unidentified nutrient. It is not easy to track down the source
of this `fact', but I did it. The nutrient in question is a
phyto-estrogen (also known as a phytosterol). Although
phyto-estrogens are not essential to human health, there is some
indication that they help prevent cancer. The study that
indicates that transgenic soybeans are deficient in
phyto-estrogens comes from Dr. Marc Lappe, who wrote the book
``Against The Grain'', a polemic against genetic engineering and
especially against the Monsanto Co., the leading company in the
field, which developed the soybeans in question.
Here is how Dr. Lappe established that genetic engineered
soybeans are defective. Understand that there are dozens of
varieties of soybeans with the herbicide tolerance trait and
over a hundred varieties of conventional soybeans. Dr. Lappe
compared one conventional variety with one transgenic variety.
He found a 12% difference. But individual soybean varieties vary
by more than 100% in their phyto-estrogen content. The FDA
normally doesn't even measure the phyto-estrogen content of
foods, but they have published one measurement each for green soybeans
(young), which had 50 mg per 100 grams and for mature soybeans,
which had 160 mg per 100 grams. Also phyto-estrogen content is
not stable. It declines with storage, by much more than the 12%
difference. But Lappe at least reports his data along with his
biased interpretation of it. Dr. Billings reports only the
interpretation without any indication that it comes from a
biased scientist whose own data show insignificant variations in
a nutrient whose role in human health is not even firmly
established.
Dr. Billings seeks only to mislead people. Not one reader in a
thousand would do what I did, track down the data. His purpose is to
plant a little seed of doubt about food safety, hoping that it will
fester in our minds, mingle with similar misinformation, and
eventually become accepted fact.
Not everything misleading is false. Propagandists are very
skilled at making true statements that seem to imply something
quite different. For example, they frequently say that the FDA's
rules about testing genetically modified food are voluntary, implying that
some testing doesn't get done. Under current law, FDA has no authority to
require safety tests for any food, transgenic or conventional, although it
can prevent the sale of foods it considers unsafe. But, in
fact, each developer of a transgenic crop has consulted with FDA and
performed every test FDA suggested. They also like to say that safety
test results are trade secrets. True, it would be legal to keep test
results secret. But no developer has done it.
Earlier I mentioned a problem with a soybean with a Brazil nut
gene. People allergic to Brazil nuts should not expect to have
to avoid soybeans, but the allergen was identified by testing
and therefore the modified soybeans were never created. Also, the
scientists who demonstrated this published their results in a scientific
journal, and this led the FDA to not allow any gene to be transferred
into a food from a species known to cause allergies.
That should be seen as evidence that the genetic engineers are
responsible people, and that testing is working well. But the
unethical opponents of biotechnology routinely present this
episode, carefully worded, as if there was a near disaster,
revealing gross problems with the current regulatory system.
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Tryptophan deaths
One of the most active anti-transgenic groups is Mothers For
Natural Law which spreads the following half-truth - that, in
1989, 37 people died and thousands were paralyzed by consuming
tryptophan made by genetic engineered bacteria. Half-truth
because there were deaths and illnesses (eosinophilia
myalgia syndrome) caused by tryptophan, sold by the ``health
food'' industry.
Tryptophan is one of the twenty amino acids which are needed by
every living thing. All bacteria already contain genes to make
tryptophan and the tryptophan sold as a dietary supplement is made
industrially using bacteria and is then purified. Showa Demko Ltd.,
the company whose tryptophan caused illnesses, genetically engineered
bacteria to make more tryptophan than was needed for the bacteria's
own life cycle.
The illnesses had nothing to do with the genetic engineering. Some cases of eosinophilia
myalgia syndrome were traced back to Showa Demko's tryptophan
manufactured as far back as 1983, years before the company used
genetic engineered bacteria. It is now known that eosinophilia
myalgia syndrome is caused by consuming excessively large doses of tryptophan, from
whatever source. Back in 1989 it was thought that the cases of eosinophilia
myalgia syndrome had been caused by some kind of contamination. All tryptophan molecules made by living things are chemically identical and there is no way that tryptophan made by genetically engineered bacteria could be different from tryptophan made by any other bacteria.
The tragic epidemic of eosinophilia myalgia syndrome makes
a very good argument for more scrutiny of the
health food industry. Presenting it as an indictment of
transgenic food is a huge distortion.
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It's Unlike Anything in Nature
Advocates of genetic modification of crops often say that it is
not significantly different from ordinary breeding techniques. They
say that virtually every crop is genetically modified and that people
have been genetically modifying plants and animals for several
thousand years. This is, of course, true, but are the genetic
transformations now possible through biotechnology different from
classical breeding in some fundamental way?
The opponents say that the new gene transfer techniques are
fundamentally different from anything that nature has ever allowed.
Since this is only a matter of how the two sides define
fundamental, it really isn't a case that illustrates
an unethical behavior by either side. There is one minor exception.
The opponents like to illustrate their case by pointing to a tomato with
a gene from a fish. This example seems to be selected from all
the myriad possibilities because it strikes a chord of negative
emotion. We just don't think that anything from a fish belongs
in a tomato. This poster child for the opponents is played up
endlessly. Their flyers and posters show a tomato with fins, or
sometimes a whole fish with a stem and a few leaves. Sometimes
the tomato is a strawberry. One is supposed to think that these
are typical examples of genetic engineering. They are not!
But the story still bothers people even when they know it doesn't
have much to do with anything we already eat. There is a feeling that
it somehow goes against nature to make such huge changes in an organism's
genes.
It might be useful to examine a few cases from nature, which can
be more complex than most of us imagine. At the very least, it
will be interesting. There are natural examples of genetic
engineering, and they are actually quite close to our lives.
Wheat is sometimes called the staff of life. Yet wheat has a
complex genetic story. It is the result of three separate
instances of natural genetic engineering. To introduce these
changes, we need to explain that wild grasses similar to wheat
have their genes dispersed among seven pairs of chromosomes. One
of the earliest known domestic wheat varieties is einkorn wheat
(Triticum monococcum), which has seven chromosome pairs, like a
wild grass. But another variety of wheat, emmer wheat, has 14
chromosome pairs. It resulted from an ``impossible'' cross
species mating with another wild grass (Aegilops speltoids). This
cross preceded modern biotechnology by several thousand years.
It either happened by itself or with the help of a Sumerian
farmer. This new plant had new characteristics that breeders, with
ordinary breeding and selection, exploited to produce many
modern varieties, such as durum wheat, which has grains that are
easy to separate from the hulls. But natural genetic engineering
was not finished with wheat. Around the time of the Roman
empire there was another ``impossible'' cross species mating
with a third wild grass (Triticum tauscii). The resulting new
variety of wheat, bread wheat (Triticum aestivum), has twenty
one chromosome pairs, the complete genomes of three separate
species of grasses. This last mating brought in the genetic
recipe for gluten, which makes dough springy and lets it hold
together when yeast makes it rise.
The record of these crosses is written in the genomes of wheat
varieties and in analyses of grain from archaeological sites.
But the latest step in the series is a grain plant with twenty eight
chromosome pairs. It is the result of a wheat-rye cross that happened
with human help only very recently, but which made no use of the
new gene transfer technology. Wheat has been involved in three
``impossible'' cross species matings during its history as a human
food, none relying on the modern DNA technology.
But the DNA manipulation techniques themselves rely on methods
developed by nature. To cut a DNA molecule at a specific place,
the genetic engineers rely on a collection of natural enzymes
called restriction enzymes, each of which recognizes a specific
site to make its cut. To join two pieces of DNA, they rely on a
natural enzyme called DNA ligase. To copy DNA they rely on the
natural enzyme DNA polymerase. These enzymes are used by living
cells to manipulate their DNA. In a few instances, they are even
used to manipulate another creature's DNA.
There is a species of bacteria, Agrobacter tumafaciens, whose
way of life is to invade a plant and cause it to create a gall,
a home for the bacterium. It works its will on the
plant by invading its cells and stitching a few of its own genes
into the plant's DNA. In effect, Agrobacter tumafaciens is a natural
genetic engineer who changes the genome of the infected plant so
that it produces food and protection for the bacterium. How
different is that from what human genetic engineers do? In fact,
one of our ways to transfer a gene into a plant cell is to use
A. tumafaciens as a ``vector''.
We need to look no further than our own bodies for a very
ancient example of a cross species mating. Within each of our
cells there are tiny bodies called mitochondria, which produce
the cells' energy. Each mitochondrion is the descendent of what
must once have been a free living bacterium. The mitochondria
have their own DNA and they make their own enzymes. In fact,
they would have all the machinery needed to run a cell, except
that they, eons ago, transferred most of their genes into our
nuclear genome.
These and other examples of natural DNA mixing across species and even
between plants, animals, bacteria and viruses, show that nature invented
genetic engineering before mankind did.
Nature even goes to the exact opposite extreme. There is a
species of fish that cannot reproduce except by a cross species
mating. The Amazon molly (Poecilia formosa), a tiny fish just a
few inches long, is a species with no males. Every Amazon molly
is a female. It bears its young alive, like its better known
relative, the sailfin molly (Poecilia latipinna), which is
commonly kept in home aquaria. How can a fish reproduce with no
males? The Amazon molly borrows the services of a male sailfin
molly. She mates and the sailfin's sperm enter her eggs,
causing them to begin development. But the male sailfin molly
makes no genetic contribution to the developing embryo. The DNA
in his sperm is wasted, which is why we can consider the Amazon
molly a totally different species. There are numerous other
species all across the animal kingdom which have dispensed
entirely with males, and reproduce by parthenogenesis, but it is
certainly a surprise to find a species which relies on males of
another species to fertilize its eggs.
But not so much of a surprise as to learn of a species of cypress in
North Africa (Cupressus dupreziana) which plays the trick in reverse.
The pollen of the cypress requires the female parts of a different
tree to produce its seed cones. The structural and nutritional
parts of the seed cones are built by the female, but the genetic component
of the seeds comes entirely from the pollen. (In medieval times, it was
supposed that humans reproduced in this way, with all heredity carried by the
sperm while the mother provided only nutrition and living space for the
growing child.)
It is true that modern methods can speed up the processes which transfer
genes between species, genera, families, even kingdoms, by millions of
times and channel them into directions of our own choosing. Ultimately
what we consider to be natural is a personal decision. But that decision
should not be affected by street theater. Nature can give you
examples of almost anything you can imagine.
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Vandana Shiva vs. Monsanto
Let us consider a widely circulated story about Indian farmers who
committed suicide. This story comes from Dr. Vandana Shiva. The
Monsanto company is supposed to have lured these farmers into borrowing
heavily to grow genetic engineered cotton. When their crop failed,
they were unable to repay their debts and hundreds committed
suicide.
Actually, India had not yet
licensed transgenic cotton, but
there were some sites where transgenic cotton was grown in test
plots, to determine scientifically whether the variety under
test would be successful and whether any problems might be
detected. The farmers who tended these test plots were not paid
for the cotton, which was meant to be destroyed. They took no
risk. But the truth is much worse. Although the suicides are a
complete fiction, Dr. Shiva is correct when she says that the
cotton crop failed. It failed because nearby Indian farmers were
incited to raid the fields and burn up the young cotton plants.
Now why would they have done that? It was because they were told
that the test plots were growing a
variety of cotton with the terminator seed technology. This was
a lie.
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Terminator Technology
So now we need to talk about the terminator technology. The fact is that
it doesn't yet exist. It's just an idea.
Suppose you are a company that develops seed varieties, at great
capital expense. If you sell your seeds to a farmer and he grows
a crop, next year he will have a large number of seeds which he
can sell. He will be your competitor.
For decades, seed companies have dealt with this problem in
various ways. For hybrid seed, the next generation's seeds do
not have the same traits and therefore the seed company keeps control of the
trait and can sell seeds year after year. For non-hybrid
seeds, the seed companies make the farmer sign a contract,
sometimes requiring that he not supply seed for others,
sometimes requiring that he not even save the seed for
replanting. But farmers can cheat.
Terminator technology, patented as the ``Technology Protection
System'', would be a rather complex genetic engineering technology.
Several different control genes would be transferred into the target
crop variety. When they all
work together, the plant would produce infertile seeds. The crop
would be edible, but its seeds would not germinate. But the genes would
not all work together unless the seed from which the plant is grown
were treated with an antibiotic, tetracycline. As long as the parent
seeds were not treated with tetracycline, the next generation's
seeds would be fertile and able to grow new plants.
Terminator technology is only suitable for plants that
self-fertilize, like cotton, soybeans, or wheat. One would not
want to make one's neighbor's crop sterile.
There's another variation, also still just an idea. Seeds could be developed
for which the new trait would be expressed only if the seed is exposed to a
proprietary chemical, available only from the seed company. So farmers
could save seeds and plant them the next year, but they would be no different
from ordinary seeds unless the farmer purchases the special chemical.
Opponents of genetic engineering call this traitor technology.
There are numerous stories worldwide that Monsanto originated
this technology with the purpose of gaining control of all the
world's seeds. These claims are so widely circulated that many
fervent advocates of genetic engineering believe that they are
true. Ms. Shiva actively peddles this story.
The truth is that the patent (5,723,765) on terminator
technology is held jointly by the USDA and the Delta and
Pineland Cotton Company. According to that company's quarterly
stockholders' report of February, 1999, commercial exploitation
of the patent is seven years away. If you can be incited to burn
a crop to destroy terminator seed, you have until 2006 to save
up for a flame thrower.
The only connection of the terminator technology with Monsanto
appeared in May 1998, when Monsanto offered to merge with Delta
and Pineland, over two years after Dr. Shiva's false story
appeared. The proposed merger has since been called off.
Also, Monsanto has stated categorically that it will not
commercialize terminator technology. (Since I first wrote this, 2006
has come and gone, but the terminator seed still doesn't exist.
But Delta and Pineland and Monsanto did merge.)
Why do the crusaders connect the terminator seed to Monsanto? It's
because Monsanto is a large multinational corporation, and can be
seen as threatening. Delta and Pineland is a small company
that would frighten nobody.
There are several ways to scare people about terminator technology.
We are supposed to be worried about poor third world farmers forced to
buy seed, from a rich multinational corporation, which they used to
get for free by saving
some of last year's crop. It is never explained why they would
stop saving their own seed.
Another scare story is: -- What if these genes were to escape into the
wild and make all living plants, worldwide, infertile. Frankly, it
takes a rather determinedly ignorant person to believe that a gene for
infertility would become widely distributed in the environment. What
are we to think when this sort of speculation is spread by a PhD?
In fact, proponents of genetic engineering have pointed out that
terminator technology could be used to prevent transferred
genes from getting into the gene pool of a related wild species.
There is one truly bad aspect to the terminator technology. If
it led to the widespread use of seeds treated with tetracycline,
we could reasonably expect that micro-organisms resistant to
tetracycline would evolve and become widespread. This would
deprive us of a useful medicine. I would hope that if any
company ever proposes to commercialize the technology, they will
first do further development to correct this disadvantage.
I have talked to many people about their attitudes toward
genetic engineering in agriculture and the issue of sterile seeds
is the one issue most frequently raised. I thought at first that
it would be useful to show people other examples of plants that
farmers cannot reproduce. We eat seedless grapes without
hesitation. Hybrid crops' seeds are not worth saving because
they don't breed true. Many fruit trees are grafted onto a vigorous
rootstock so their seeds can never grow into hardy trees. But
these examples changed nobody's mind. To many people, the sterile seed
technology crosses a line between what man may or may not do to
other living things.
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Biodiversity
The argument goes as follows. ``All over the world, there are farmers
growing local varieties of crops, all different from one another. But
transgenic crops are all identical. They will crowd out the local
varieties and each basic crop will be the same worldwide. By bad luck,
some fungus or other disease may come along that will wipe out that
variety. The other varieties might have included some with resistance
to the disease, but by adopting transgenic crops we would have lost
the basic crop completely and finally.''
The argument starts with a true statement. There are numerous local
varieties of most crops, called landraces, especially in the
region of the world where the crop originated. For example, Peru has
hundreds of varieties of potato. These are a reservoir of
biodiversity. Traditional breeders have regularly mined this genetic
diversity to improve the characteristics of crops.
The rest of the argument is untrue and nonsensical. First, transgenic
crops are not all identical. Once a gene has been transferred into one
variety of, say, potato, that potato is crossbred with many other
varieties and dozens or hundreds of genetic combinations are created.
Just as there is no best potato, there is no best transgenic potato.
There is not going to be a worldwide uniformization of crops, period.
Second, local varieties may be crowded out, or not, according to the
decisions of individual farmers. There are many varieties of crop that
are more productive than many local landraces. This isn't unique to
transgenic crops. The danger of landraces being lost is real, but has
nothing to do with genetic engineering. In fact, transgenic seeds are
usually more expensive than other commercially available seeds, so
they would be less likely to be adopted by traditional farmers. But
the real solution to the preservation of landraces is to establish
``germ banks''. A few hundred seeds of each variety can be
institutionally preserved. This is already happening. There are landrace
banks for most major crops. Many of these landrace banks were established
decades before there were any transgenic crops.
Third, thanks to biotechnology, there is no longer the threat of
complete extinction of anything! It has now become possible to take
DNA of a single cell of a plant or animal and reproduce its genes
indefinitely. Endangered species might be saved from extinction, or even
recovered from extinction by genetic engineering.
A typical plant might have 40,000 genes, including perhaps 1,000 that
differ from one variety to another. It is these 1,000 that constitute
the biodiversity of the species. Genetic engineering can introduce new
genes to the species' gene pool. That represents increasing
biodiversity. This is so obvious that in order to claim the exact
opposite, unscrupulous propagandists have had to weave in four
separate untruths, that all transgenic crops are identical, that
landraces are more in danger from transgenic varieties than from other
commercial breeds, that landraces are not being preserved, and that
the danger of extinction of any crop is increased by genetic
engineering.
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The Reaction to Golden Rice
Earlier we mentioned rice with vitamin A, developed by Swiss scientist
Ingo Potrykus and his German colleague Peter Beyer. Nicknamed golden
rice because the beta carotene gives the rice grains a distinctive
golden color, this achievement posed a huge problem for the crusaders
against transgenic agriculture. It seems to be a really good thing and they
couldn't say anything bad about it.
Consider.
First, it's meant to provide a nutritional benefit to
poor people suffering from a severe vitamin A deficiency.
Preventing its use could be seen as depriving the third world poor of
much needed help. In fact, for each month of delaying its introduction
by insisting on excessive testing, the crusaders could be blamed for
an average of 50,000 cases of blindness.
Second, much of the crusaders' case against GMOs is about
domination of the third world by multinational corporations,
dependence of farmers on large companies, concentration of
profits, etc. But golden rice was developed without
corporate money. Potrykus and Beyer were funded by the Swiss
government, the European Union and the Rockefeller Foundation.
They are making golden rice available free to the poor farmers.
Third, the crusaders loudest claim was that GMOs were insufficiently
tested for safety. But this was a preliminary product, still being tested.
Fourth, there was no conceivable environmental problem. Rice plants
already produce beta carotene, although not in their grains. So the escape
of the transferred genes into wild rice relatives could not possibly
matter. Besides, rice pollen never travels more than a few millimeters.
All the usual complaints about genetic engineered crops were either
not applicable to golden rice, or were vastly outweighed by the
humanitarian advantages.
It might have been better strategy for the crusaders to treat
golden rice as a special case, an exceptional case of a bad technology put to
a good use. But instead, they decided to denounce it.
Greenpeace threatened to interfere with the research but they were unable
to do anything because Potrykus' research facility was too secure, even
grenade proof.
Still, Potrykus received threats and hate mail. The rumor was spread that
golden rice would cause impotence and hair loss.
In 1995, the researchers tried to send samples of a new rice
strain to the International Rice Research Institute. A graduate
student, sympathetic to Greenpeace, passed them shipping
information and Greenpeace stole the samples from the package delivery
company, putting on its usual street theater with protective
clothing and gas masks.
Dr. Potrykus then arranged a meeting with Greenpeace campaign director
Benedict Haerlin. He attempted to explain why the golden rice project
was beneficial and innocuous and asked Haerlin to explain Greenpeace's
objections to his work. But Haerlin said that Greenpeace opposed his work
as a matter of principle.
In the spring of 2001, the biotechnology industry finally began
a slick propaganda campaign of its own, launching television ads featuring
golden rice. This, even though industry's only contribution to the project
was allowing Potrykus free use of its patented techniques. In response
to this campaign, Haerlin briefly changed his mind, stating that
despite Greenpeace's objections to genetic engineering, they would
not stage raids to vandalize the test sites planned in the Philippines. But a
few days later, he retracted the statement, reserving the ``right''
to attack the test plots.
Soon, Vandana Shiva got into the fray. She issued a report
calling golden rice a gigantic hoax. She claimed that its
vitamin A content was so minuscule that a child would need to
eat many kilograms per day to get the recommended daily
requirement of vitamin A. But her calculations were based on the
least favorable choice of each possible factor. She used a
recommended daily allowance (RDA) instead of a minimum daily
requirement (MDR), mixed up the weight of dry rice with that of cooked
rice, used Potrykus' published research results about the first
plants to display vitamin A, rather than the best, and assumed
that there was no cooking oil and no other source of vitamin A in the eaters' diet.
After correcting Ms. Shiva's
exaggerations and errors, the best strain of golden rice would
still only provide about 15% of the RDA, enough to
prevent blindness but far from an optimum. But today's best varieties
can easily supply all of the daily requirement.
Shiva claimed, correctly, that industry was using golden rice to present
transgenic agriculture in the most favorable light. Soon the other
parties to the campaign began spreading her calculations, ignoring
Dr. Potrykus corrections.
Finally, in January 2001, the rice seeds were transferred to
IRRI and are being used for experiments by over twenty research
institutes, crossing golden rice with other varieties. There is
still plenty of testing to do before the rice can be released to
farmers.
Another question is whether the third world consumers will accept
golden rice. There is some
reason to think not .
Greenpeace and the other critics have frequently stated that the
money spent on developing golden rice could better have been
spent on distributing capsules of vitamin A to the poor
worldwide. Such distribution had already been happening for
about fifteen years, funded by the World Health Organization,
costing about $100 million annually, but it hasn't solved the problem of
vitamin A deficiency. Pills often don't make it to the poor.
Besides, a constant theme of the protesters has been that the
poor of the third world need to break out of their dependence
and become self sufficient.
Faced with a development like golden rice, the extremists choose to
remain extremists.
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New Viruses
A virus consists of two parts. One part is protein, and there
are virus genes which tell an infected cell how to make that
protein. The protein serves as a coat which protects the virus
and helps it to get inside the cell it infects. Without the DNA,
however, the protein coat is harmless.
The other part of the virus is its DNA, which includes both the genes
for making the coat protein and the control genes which take over
control of the infected cell's functions. The latter type of
genes are switches, known as promoters, which make the cell read the
virus' genes.
Genetic engineers have borrowed promoter genes from viruses and
used them as the switches to turn on the useful genes. One such
promoter gene comes from a virus which infects cauliflower, the
cauliflower mosaic virus. The reason it is a popular switch
is that scientists know exactly how and when it is turned on.
Genetic engineers have also created virus resistant crops using
virus genes. The idea is to insert the gene which specifies the
virus' coat protein into the DNA of plants threatened by the
virus. The coat protein is harmless, but it stimulates the
plant's natural defenses. When a real virus shows up, the plant
is ready.
A few critics, using language that sounds scientific, have
claimed that these bits of virus DNA are particularly dangerous.
The arguments are actually nonsense. One fear is that plant
virus A will hide its DNA inside the coat protein of plant virus
B, becoming a new kind of virus with new infectious
characteristics. But if this chimeric virus were to infect a cell, its
DNA would make the cell create only new type A viruses, not new
hybrid viruses. Putting a bearskin on a wolf might make a wolf
seem like a bear, but its offspring would be exclusively wolves.
The other fear is that the promoter gene from the cauliflower
mosaic virus makes a particularly weak link in the DNA chain,
making the modified DNA
unstable, very susceptible to mutations. The only scientist
who believes that the promoter gene (from the cauliflower mosaic
virus) is a weak link is Dr. Mae Wan Ho. Other molecular
biologists disagree. But if Dr. Ho is right, it would imply that
cauliflower, broccoli and its relatives are naturally unstable.
The cauliflower mosaic virus commonly infects them. Even if the
plants are not infected, the virus promoter gene is part of
these vegetables' DNA, because natural genetic engineering put
it there eons ago. Yet cauliflower is neither more nor less
susceptible to natural mutation than other plants or animals.
Viruses are frightening organisms. They can cause frightening
diseases, some of which cannot be treated. AIDS and ebola are
virus diseases, along with herpes and influenza. The
biotechnology opponents try to twist our fear of viruses into
fear of biotechnology.
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Viruses in Africa
Between 1950 and 1980, crop scientists were able to develop
varieties of several basic food crops which yielded three times
as much food per acre. As mentioned earlier, for leading this
work, Dr. Norman Borlaug was awarded the Nobel Peace Prize. It
has been called the Green Revolution. It required painstaking
persistence. The variety of wheat most productive in northern
China is not the same as the variety most productive in Kansas
or in Peru. Different varieties do better in highlands or in
lowlands. The rice most suitable for Vietnam is different from
the rice most suitable in Japan. In all, some hundreds of high
yielding strains of basic crops were developed and, as
important, made available to the poor farmers of the third
world. The important crops improved were wheat, rice and corn.
The green revolution happened before the development of today's
biotechnology. It happened with conventional breeding.
Unfortunately, the green revolution missed Africa. The
basic crops grown in Africa are not rice, wheat and corn, but
millet, yams and cassava. Yields of these African crops were not
improved much during the thirty year green revolution. It is no
coincidence that Africa today is the continent with the most
starvation.
People who care about adequate food for the poor of the
third world are now concentrating on Africa. But the hunger in
Africa is an emergency. It cannot be quickly solved by breeding
new crops. In the short term, the solution is to send boatloads
of grain to the countries with the most dire emergencies.
But there are also scientists working on crop improvement.
Kenya's Florence Wambugu, who was trained in biotechnology in
the US, has developed a genetically engineered yam (sweet potato)
which is immune to a pervasive plant virus. In 1999, in one
African country, virus infections destroyed half the
cassava
crop. Dr. Wambugu's students are developing cassava plant
varieties which resist both viruses and fungi.
Dr. Wambugu expresses anger at the affluent
European protesters who would stop her work on the basis of
imagined dangers. In Africa, the dangers are not hypothetical.
The starvation is now.
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Where the Transgenes Go
Remember that genes are analogous to sentences in a document.
Critics like to claim that the process of gene transfer could
put the new gene anywhere randomly in the document, possibly
messing up other genes. By analogy, if a document had read, in
part, ``don't drink the water!'' and the inserted sentence were
``be happy!'', one might get the construct ``don't be
happy! drink the water!'' Of course, such a random insertion
could change the meaning of either or both genes. Since almost
anything could happen, goes the argument, it would be impossible
to test enough to discover the problems caused by gene transfer.
There are several reasons why this criticism is misleading.
To begin with, although the genetic engineers do not have perfect
control over where a transferred gene will go
in the genome, they know, after the transfer, exactly where it
did go. A plant for which the gene was transferred into the
wrong place would be discarded and the engineers would try again.
Besides, not having perfect control is a far cry from having no
control and there are many more sites for safe gene insertion than
for disruptive insertion.
Yet there is some leftover truth to the assertion that a gene
transferred to a different species could have unanticipated
consequences. It's just that genetic engineering, while not
perfect, is much more precise than any other breeding technique.
In every act of sexual reproduction, there are millions of
possibilities for unanticipated consequences. Whereas genetic
engineers transfer only one gene, conventional breeders use the
sexual process, which mixes together thousands of genes. ``don't
be happy! drink the water'' happens all the time in conventional
breeding.
It is also misleading to imply that the genome is such a stable
document in the first place. In nature there are at least four
separate mechanisms at work to mix up genomes.
The critics of genetic engineering mean to leave you with the impression
that nature has evolved a finely tuned but fragile system of
inheritance but that genetic engineers have no good idea what they are
doing. But actually, the genetic engineers make only small well
controlled modifications to a genome, whereas nature often makes large
and random changes. The likelihood of unexpected effects in transgenic
technology is small. Unexpected changes in conventional
breeding are virtually certain.
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A Ban on Glyphosate
We earlier mentioned glyphosate, an environmentally benign herbicide.
It is biodegradable, lasting approximately two days after use, and its
molecules bind to soil so it does not wash into streams or enter
groundwater. Even if some madman were to dump it into a waterway, it
is 230 times less toxic than
the herbicide it replaced. It has been found safe and
approved for use in almost every country, including all the
countries of the European Union. Yet the anti-transgenic crowd
seeks to ban it in Europe using the pretext of uniformizing
regulations from one European country to another.
What reason is given for banning the safest of all herbicides?
Two reasons. It is supposed to be `implicated' in non-Hodgkins
lymphoma, and it is alleged to harm beneficial insects.
Examining the evidence for these two claims reveals how
some opponents of GMOs will use anything, no matter how shaky,
to achieve their purposes.
Non-Hodgkins lymphoma patients were asked to recall what
pesticides they had been exposed to in the past several years.
A statistically insignificant number of them (four) mentioned
glyphosate, not surprising since it is so widely used. Even
though the investigators considered this association
meaningless, it was enough for Greenpeace to demand a ban.
The claim about harming insects is even weaker. Several species
were exposed to glyphosate and the control group were not
exposed. There was similar mortality in both groups. But
there was mortality. This is enough for Greenpeace to claim that
glyphosate kills beneficial insects. Greenpeace ignores a
follow-up study by the International Organization for Biological
Control, which concluded that glyphosate was exceptionally safe.
One might have expected the IOBC to be hoping that it would find
something wrong with glyphosate, since its charter is to
popularize biological controls. But IOBC's scientists are ethical.
The real reason for banning glyphosate is that it is made by
Monsanto and used as the herbicide for the
herbicide-resistant transgenic soybeans.
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Labelling Transgenic Food
This brings us to the issue of labelling.
Once the opponents instigated a doubt about the safety of
genetic engineered foods, and remember that there has not, in
ten years, been even the slightest evidence of that, the next
step was to agitate for labelling. Why, after all, shouldn't
consumers have a choice?
I agree people who want to avoid transgenic food should be able
to make that choice. But labelling can take two forms. One
could label food which is not transgenic, or one could label
food which is transgenic. I can't imagine anyone objecting to
labelling foods which are transgenic-free. But the anti-transgenic
demand is adamant for the other choice. We can say that the
difference is between those who would label the non-transgenic
food with a smiley face and those who would label transgenic
food with a skull & crossbones.
Labelling sounds so reasonable. How could anyone oppose it if
they didn't have something to hide? But labelling has a down
side. It costs. The cost is not in the ink to print the label.
It is in keeping the products separate. We are talking now
mostly about soybeans and corn. These grains are harvested by
the hundreds of tons, shipped in railroad cars, stored in grain
silos, sold in futures contracts. Approximately 70% of processed
foods in the US have some ingredient derived from biotechnology.
This includes most milk and cheese, sugar, soy products, corn
and corn sweeteners, vegetable oils, etc.
63% of US grown soybeans are now transgenic. Neither buyers nor
sellers distinguish between transgenic and conventional
soybeans. Your tofu is a mixture of both kinds. (In my local
supermarket, there is only one brand of tofu available and the
manufacturer has recently decided to use only organic soybeans,
which are specifically labelled non-GMO. At the same time, the
package size changed from sixteen to fifteen ounces and the
price was raised by $.25.) To keep the two kinds separate, we
would need, at a minimum, to have two separate distribution
channels, two storage systems, two futures markets.
In my opinion, the pressure for skull & crossbones labelling is really
a pressure to increase the cost of the genetic engineered food. So
far, the transgenic food has had only producer advantages -- it is
cheaper to produce. Take away its cost advantage and it is no
better than the conventional foods. Never mind that corn with
the Bt trait, one third of the US crop, is grown without
pesticides. Never mind that the transgenic soybeans prevent
soil loss and global warming. The Economist magazine estimated
that segregation of grains would add a 25% premium to the price of some processed foods,
like packaged cereals. This is probably an over-estimate, but we
should remember that these costs will fall inordinately on
people with low income.
But if this were the only problem with labelling, the food
industry giants would quickly adopt grain segregation and labelling. They are
being forced into grain segregation anyway by the labelling
regulations of nations that import US grain. The industry is
really concerned that the labels will make it easier for groups
like Greenpeace to boycott their products. Stop the scare
campaigns and the resistance to labelling will disappear
overnight.
If you doubt that demands for skull & crossbones labelling can be
used to purposely create a disadvantage, imagine what your
reaction would be if someone were to propose that products
assembled by hispanic workers must be so labelled. The public
demand for labelling would be justified by a ``right to
information'', but just below the radar screen you would not be
surprised to hear that hispanic workers might be illiterate, or
might be illegal immigrants, or might be drug users. But you
would recognize that the demand for labelling was meant to
disadvantage hispanics.
We have established a precedent in this country about labelling.
The government does not mandate labelling without a very good
reason. The main exception is when safety (skull & crossbones
label) is involved. Once the government decides that, say, a
certain chemical pesticide is safe, nobody can require the food
grown with that pesticide to be labelled. When a segment of the
consuming public wants a label (smiley face) about a trait that
it cares about, the market provides such a label and it is
reflected in the cost of the product. For example, there are
people who prefer to eat food grown with no chemical pesticides.
They buy ``organic'' food. Everyone understands that the label
``organic'' means that the food was grown without pesticides.
Everyone also knows that they have to pay more for the food
labelled organic.
Similarly, orthodox Jews have certain religious rules about what
they eat. These include a requirement that cows and chickens
must be slaughtered in a particular way. This is a requirement
for the Kosher label. Jews do not expect all meat to have a
label detailing how the animal was slaughtered. Even in Israel,
the people who want the label pay for the privilege, and kosher
meat is often quite a bit more expensive that ordinary meat.
One has to be skeptical when the demand for giving consumers
more information comes from the same people who are so blatantly
broadcasting misinformation.
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Labelling as a Trade Barrier
Foreign governments are motivated to oppose genetically
engineered food as a trade barrier. The United States sells one
third of its crops overseas. Europe used to buy $200 million
worth of corn and soybeans per year from American farmers. This
year it will probably buy none because we are unable to supply a
segregated product. Even farmers who grow traditional grains
cannot sell them to the European Common Market because the ECM
has not yet specified a clear lower limit on how much transgenic
content would require a transgenic (skull & crossbones) label --
e.g. one bean in a pound, in a ton, in a shipload? Even such a
clear limit would leave room for confusion and an excuse for
excluding the imports. Do you consider food to have transgenic
content if it contains oil pressed from transgenic corn or
soybeans? No test can tell the difference. Sugar made from
transgenic sugar beets cannot be differentiated from other beet
sugar. Do you consider a chicken transgenic if it ate transgenic
chickenfeed, ever? This is one of the demands of the most vociferous opponents.
(Parenthetically, Europe has decided on the criterion for a
non-transgenic (smiley face) label, 1%. So we have the
paradox that a product made with only a few transgenic grains
could be labelled as either transgenic or as transgenic-free, but
cannot be sold in Europe without any label.)
It happens that Europe sells a great deal of cheese to the
United States. Almost all of it is made using chymosin from
genetic engineered yeasts. None of the transgenic food opponents
call for cheese to be labelled for genetic engineered content.
The governments of the European countries do not want this even
to be revealed. They are trying to keep American agricultural
products out of Europe, not vice versa, and one of the major
ways they do it is by requiring the transgenic crops to be
segregated. This is a ploy. They have already found several
transgenic crops to be safe, but by requiring them to be
segregated, they can get around the World Trade Organization
rules, at least for a while longer.
The most blatant campaign against American imported food has
been managed by Italy's minister of agriculture, Pecoraro
Scanio, a Green Party member of the ruling coalition. He has
vocally denounced transgenic products as ``mutant'' food,
withheld research funds from Italian plant scientists who say
transgenic food is adequately tested, and
seized imported food and seeds in warehouses based on the rumor that they
might have some transgenic content. But recently a German
magazine published an expose revealing that Italy's most popular
variety of spaghetti wheat was developed using mutations induced by
radiation. (Never mind that this had happened decades ago.) It was
a huge embarrassment for Scanio, who had to promise to
investigate so he could gain a little time. How will he be able
to justify allowing real mutant food from Italy?
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Environmental Scare Stories
Let's move on to the environment.
We mentioned earlier a concern that some genetic engineered
crops could cross breed with wild relatives. To the
pseudo-environmental groups (those who like to call themselves
green even though much of what they advocate would harm
the environment), this absolutely rules out any permissible
use. Their argument goes as follows: ``We don't have any idea
what plants could cross breed with what other plants, and we
don't have any idea what effect the unusual genes would have in
the wild plants. Therefore we should take no chances.''
In fact, hybridization between different species is extremely
uncommon and it has never been observed between distantly
related species. A tomato won't cross with a potato, even
though they are both members of the nightshade family. Yet the
GE opponents would have us believe that just about any plant can
hybridize with any other. And they have quotes from PhDs to
prove it.
Actually there is exactly one controlled experiment showing a hybridization
between a genetic engineered crop and a wild species. The crop
was a transgenic canola (oilseed), with that same herbicide
tolerance gene we have encountered before. Here is what PhD Jeremy
Bartlett, of the John Innes Plant Research Center of Norfolk,
England, wrote to the Manchester Guardian. He said we don't know
what plants will hybridize with what other plants. He said that
there is a documented example of transgenic canola hybridizing
with a wild mustard. He went on in the same letter to talk about
the possibility of gene transfer to soil organisms.
Dr. Bartlett is a PhD in biology. He surely knows that there is
little basis for speculating that plants will pass genes on to soil
organisms. But let's give him the benefit of the doubt where a
speculation is concerned. Still he must have known that the
documented case he was referring to was observed at a test plot
of the John Innes Research Center, his own institution. The
transgenic canola was planted in the center of the plot and
various other species were planted at various distances to
measure the rates of hybridization. There was only one case
observed. The canola hybridized with the wild mustard.
Jeremy Bartlett means for you to think that if an oilseed can hybridize with
a wild mustard, then anything can hybridize with anything.
Fortunately, the John Innes Center puts its research reports on
the world wide web, so I read the actual report. Guess what?
Canola is a hybrid itself, a cross between Brassica rapa and
Brassica napus, two closely related wild plants in the same
genus. Brassica rapa is wild mustard! So we don't have
evidence for a transgenic crop hybridizing with just about
anything else imaginable, beyond the capability of man to
anticipate. We have evidence of a plant crossbreeding with its
closest relative, placed in the test plot because it was so
likely to crossbreed, and it was the only case observed. When the
biotechnology opponents write or talk about this, they always
say wild mustard and canola, never Brassica rapa and napus. Dr.
Bartlett means to play with our minds, to mislead us. Hybridization with wild
plants is a concern, but it is a managable concern.
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Vandalization of the Fields
This doesn't just happen in India. In 2000, eight test plots of
transgenic oilseed developed by the AgroEvo Company were
torn up in the British Isles. One more was sprayed with
petrochemicals and another was mowed with a reaper, in broad
daylight with TV news alerted. The last attack was organized by
Greenpeace and the action was led by Lord Peter Melchett, head
of England's chapter of Greenpeace. He was arrested and faced a
trial, which he used to present the case against transgenic
foods. He was acquitted! Greenpeace claims that these crops are
a threat to the environment, yet Greenpeace organizes the
vandalism that destroys the test plots which could prove and
quantify this threat if there is any.
Incredibly, in the aftermath of such vandalism, the protesters were able
to successfully demand that the British government make public the locations of
all future test plots. Not surprisingly, many British farmers have therefore
decided not to take part in such experiments.
Test plots of Bt corn were vandalized in California, Maine,
Minnesota and Vermont that summer.
So-called direct action has not been limited to action against
the plants. A university biology laboratory in Michigan was fire-bombed.
Activists have attacked numerous research facilities to break windows
and slash tires.
Most of this vandalization is committed by sincere people who
have been stirred up by stories spread by groups they have come
to trust. But in a surprising number of cases, the fields
vandalized have had nothing to do with genetic engineering.
Protesters in Britain who tore up a test plot of tomato plants
in the night thought that they were frustrating GMO research,
but they actually pulled up research plots of ordinary tomatoes.
The genetically modified tomatoes were growing somewhere nearby.
In March of 2001, a forest of 800 aspen trees in Oregon was cut
down by an unknown group, who then sent a letter to forest
geneticist Steve Strauss, whose experiment they had destroyed.
The letter claimed that his experiment was a menace to the
environment. How? The trees were sterile. They could produce no
seed, or pollen. Then in May, it was probably the same group
that burned down a plant research center. Calling themselves
Earth Liberation Front, they may not have known that scientists
there were trying to save a rare plant, the showy stickweed,
from extinction, using a cloning technology called tissue
culture. A hundred of the plants perished in the fire.
Approximately three hundred remain alive somewhere in the wild.
The Earth Liberation Front's members no doubt consider
themselves virtuous for their love of the environment. Perhaps
they justify the accidental eradication of one quarter of the
population of an endangered species as a necessary casualty of
their war against biotechnology. So far, the objective record
has biotechnology helping to protect the environment while the
Earth Liberation Front has set fires and killed trees.
There are internet sites which encourage this vandalism. Potential
activists are offered advice on how to find likely targets by
looking in the lists of projects carried out in universities. All
a project needs to be targeted are sponsorship by industry or
some key words like genetic in its title.
Bills have been filed in several agricultural states to make it clear,
as if it weren't already clear, that destruction of research is
criminal activity. The staff of the Florida Senate Judiciary Committee
had documented forty cases of such destruction in the United States
during the three years ending in April 2001.
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The Monarch Butterfly Story
Scarcely a week goes by without someone dressing up in a butterfly
costume to protest genetically engineered food.
Dr. Losey's experiment was as follows: He sprinkled Bt
corn pollen onto milkweed leaves, then put monarch butterfly
larvae (caterpillars) in a jar with only the pollen dusted
leaves to eat. He observed high mortality.
Now here is some background to help you decide what this means.
Monarch butterflies eat only nectar, not pollen, and
caterpillars eat only milkweed leaves. Farmers don't let milkweed grow in
cornfields, although it may grow on roadsides near cornfields.
Corn pollen is heavy and seldom drifts more than ten meters
from the tassel. Because of the refuge strategy, each field
of Bt corn is surrounded by several rows of conventional corn.
Very little Bt pollen gets to the edge of the corn field.
Furthermore corn pollen is shed for only a few weeks and monarch
butterfly larvae do not hatch until after most of the pollen is gone.
Dr. Losey told reporters that his experiment was inconclusive
because he had not controlled for the amount of pollen dusted
onto the milkweed leaves. But, a controlled experiment two
years earlier had shown negligible mortality of monarch
caterpillars under realistic conditions. This study had been
submitted to the EPA as part of the regulatory process.
Corn which is not Bt protected is grown with insecticides which
kill any insect the spray reaches, including beneficial insects.
Bt corn is now 30% of the US crop and the monarch butterfly
population is on the increase.
The most advanced variety of Bt corn produces the Bt toxin only
in its stalks and leaves, and does not produce any toxin in its
pollen. The company which sells this variety is Monsanto.
While the organized opponents of transgenic food were using Professor
Losey's preliminary experiment as ammunition in a propaganda war, Dr. Losey was doing what
scientists are supposed to do, gathering more data. He and other scientists
have found that under realistic conditions, monarch caterpillars would almost
never be exposed to enough corn pollen to harm them. Even when the caterpillars are
force fed large amounts of pollen, only one variety of Bt corn contains enough toxin
to matter. That variety, called Event 176, was never planted on more than two
percent of American farmland, and has since been withdrawn from production. Several other
teams carried out additional experiments to quantify the effects of Bt pollen on
monarchs and other butterflies. These studies all reported
negligible effect. These controlled studies were mostly ignored
by the media.
A very good case is made by Dr. Losey that a monarch
butterfly is better off near a Bt cornfield than near a
cornfield which is sprayed to control the European corn borer.
Of course, the butterfly would be better off still near an
organic cornfield. But without chemicals, the borer can cause
losses of approximately one third of the corn crop. It is simple
arithmetic to see that if we relied on organic corn, we would
need to use fifty percent more land.
The more land we use for farming the less land is available for
wildlife habitat. So the propagandists, gleefully pushing the
monarch butterfly story for all it is worth, may be making life
worse for the butterflies and eventually for all wild things.
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Blocking Famine Relief
The moral divide between responsible and irresponsible critics of
transgenic food was made very clear in the fall of 2002. There was
a terrible famine in Southeast Africa, the worst ever recorded. In eleven
countries, the shortfall in harvest threatened up to fourteen million people
with starvation. The United Nations' World Food Program began to ship and distribute
thousands of tons of food to Africa, mostly corn from America.
Incredibly, the leaders of three African countries, Zimbabwe, Zambia and Malawi,
told the World Food Program that they could not distribute American corn in their
countries because it might be genetically engineered.
Why would African leaders prefer that their people starve rather than eat
American corn? No African could possibly believe that his country's food
safety standards are better than America's. But organizations like Greenpeace and
Friends of the Earth had warned the Africans that some of their farmers might save the genetically
engineered seed for the next year's planting. Then those organizations would lobby
the European Union to require that all of Africa's future agricultural exports to
Europe would have to be traceable to prove that they were traditional crops. Of course,
Africa doesn't export corn to Europe, but it does export products like coffee, and
cut flowers. The connection between corn and cut flowers is a mystery to me. This was
just a kind of blackmail.
The World Food Program is not interested in political or philosophical disputes, only
in providing famine relief. They knew that they simply could not find enough corn to
feed fourteen million people without accepting American corn. The United States
contributes sixty percent of the WFP's food aid. They pointed out that if the corn was
milled to flour it would be impossible for farmers to save seed for planting. After
considerable negotiation, Zimbabwe and Malawi agreed to accept American corn to feed
their people if it was milled.
Zambia, however, refused to budge. President Levi Mwanawasa said that he would not allow
his people to be poisoned. He was cheered by some of the opponents of genetic engineered
food, like Friends of the Earth, and Vandana Shiva. Greenpeace, with a keener sense of
public relations, said that it would be better for Africans to eat transgenic corn than
to starve, but blamed the United States for using Africa's famine as an opportunity to
dump its surpluses.
American transgenic corn was distributed in Zambia during four previous famines without
any problems. In some places the WFP had stored supplies of corn in warehouses.
Mwanawasa at first said that those supplies could be used to feed Angolan and Congolese
refugees living in Zambia, but then he changed his mind and insisted that it be taken
out of his country. Before this could happen, starving peasants overpowered warehouse guards and
seized tons of corn.
This was not the first time that GMO zealots tried to prevent relief supplies from reaching refugees.
In 1999, a cyclone devastated the Indian coastal state of Orissa. America contributed food relief. Dr. Shiva
had it tested, found that some was genetically modified, and demanded that it not be distributed.
Fortunately she was ignored then. Now, however, many Africans are dying of starvation because of the
anti-GMO movement. It is immoral to use starving families as pawns in a propaganda battle.
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Using the Courts
If you can't suppress transgenic crops by saying that they are
deadly to eat, or that they are bad for the environment, there
are always the courts. Jeremy Rifkin, the perpetual opponent of
scientific advances, filed an antitrust suit against the five
largest companies with genetic engineered products, including
Monsanto and Dupont. Another perpetual gadfly filed a suit in
Federal Court whose plaintiffs were a rabbi and a mullah. Their
claim is that cross breeding of different species is an affront
to their religion. (Both of these suits were eventually
dismissed.)
In 2007, GMO opponents successfully sued to restrain Monsanto from
selling seed for a herbicide-resistant variety of alfalfa, even though
it had been subjected to the usual round of regulatory approvals, until
after the Environmental Protection Agency issues an Environmental
Impact Statement - the claim was not that the environmental impact had
not been studied, only that the EIS had not been issued. No previous
crop introductions, even transgenic crop introductions, had ever needed an EIS.
By that time, farmers had already planted 200,000 acres of GMO alfalfa.
Judge Charles Breyer issued an injunction against future seed sales, but he
also ruled that the GMO alfalfa already planted was OK to grow and harvest.
Using the courts is particularly effective in Europe. The rules
of the European Union require all countries to agree before a
new product can be imported. Since all the European Union
members are democracies, they all have courts, so there are lots
of chances to sue to keep the new product out of at least one
country and therefore out of all of Europe. Even if you can't
win a lawsuit, you can always appeal, and when the appeal is
lost, you can sue again with a different complaint. Someone in
the government in every country is disposed to protect the local
farmers from foreign imports. Europe has kept almost all genetic
engineered food out. We are very close to a trade war with
Europe over American agricultural exports, many of which have
nothing to do with transgenic crops, but the US Commerce
Department is working behind the scenes to give Europe the
message that our patience is wearing very thin.
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The Precautionary
Principle
When the GMO opponents are presented with criticism of their
facts and falsehoods, they fall back on the following argument:
``We can't prove any particular problem with genetically
engineered agriculture, but until we can be sure that there is
no possible problem, it is necessary to err on the side of
caution.''
As for productivity increases which biotechnology might make possible,
the critics say that there is plenty of food available, and that hunger is
caused by poverty, not scarcity.
In the US and Europe, where standards of living are high, this
point of view is at least defensible. In the third world, where
food is scarce and agricultural productivity is poor, such an
argument is rightly regarded as elitist. But even in prosperous countries,
the ``precautionary principle'' can be taken to foolish extremes.
I grew up in New York City at a time when just about every
public health expert advocated adding fluorides to the water
supply to prevent dental decay. This public health measure was
delayed by decades by people who were persuaded that
fluoridation might cause anything from tooth discoloration to
epilepsy. As a result, I have a mouth full of fillings. My
children, who grew up with fluoridated water, have never had a
single cavity. The misuse of the precautionary principle has
cost me many thousands of dollars and dozens of hours in the
dentist's chair.
In my grandparents' generation, goiter, a disease of the thyroid
gland, was common. Victims had a disfiguration of the neck, and
were frequently cold and listless because the thyroid gland is
involved in regulating the body's energy production. Goiter is
caused by iodine deficiency. Adding iodine to table salt has
made the disease rare today. But at that time, it was resisted
fiercely with just the same sort of campaign as was conducted
about fluoridation, the same sort of campaign that is today being
conducted about genetic engineered food.
When choosing between alternatives it makes no sense to let an
unlikely and hypothetical problem outweigh an actual important current
problem.
The logical flaw of the precautionary principle is that it fails to
recognize that doing nothing is also a choice.
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Have the GMO proponents been Honest?
While it is true that the major blame for misinformation has to lie with certain
opponents of genetic engineering, the other side is not without its faults.
Proponents are fond of saying that genetic modification is as old as agriculture,
implying that there is only a minor difference between selective breeding and
transferring genes. It is absolutely true that there can be unanticipated consequences
from older methods of crop modification, but that should be taken as an argument for
strict regulation of all new crop introductions. It is not a valid argument to support
safety of GM crops. There are special concerns when a gene is introduced that
had never been in a species' repertoire.
The companies who have developed major transgenic crops have also tried to
use ``golden rice'' as a poster child. But this is not fair. The companies made
little if any contribution to the development of vitamin A enriched rice, apart from
allowing the use of their patents. Considering that the poorest farmers in Asia
don't have the cash to pay for expensive seeds, these patents would not have netted
the biotech companies any income anyway. Besides, golden rice is meant to benefit
the consumer who eats it, whereas almost all the biotech companies' products have
been meant to bring advantages to farmers.
In the same way, the companies have been less than completely honest
about the environmental advantages. Cotton pesticide use has been
dramatically reduced, but for most other crops the reductions have not
been huge. For example, Bt corn resistant to the European corn borer
doesn't reduce pesticide use very much, for the simple reason that corn
borers are too hard to control with pesticides, so little was used.
Virus resistant crops have increased yields, but viruses were never controlled
with pesticides.
There has also been a tendency for proponents to exaggerate the promise
of genetic engineering to reduce hunger. Other technologies can do
much more in the short and intermediate term. A huge amount of food
rots before anyone can eat it. Rats and insects spoil much of the
rest. Investments in refrigeration and plastic wraps could save vast
amounts of food in the very parts of the world where it is scarce.
Sometimes, just after a crop is harvested, heavy rains make roads
impassible and the farmer can't get his crop to market before it
spoils. Decent roads would do much to combat scarcity.
However, these examples are just not comparable to the gross
misrepresentations that have come from the opponents of transgenic farming.
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Who is to Blame for Problems with Food?
A great deal of negative propaganda has had an interesting effect. The image of
genetic engineers is now so negative that some people are beginning to
attribute whatever they don't like about food to genetic engineering.
For example, when the debacle of Starlink corn was first reported, hundreds of
people reported that they had suffered allergic reactions caused by eating it.
It happens to be quite easy to check that claim. If Joe has had an allergic
reaction to X, his blood must contain antibodies that react to X. Dozens of the people
who reported these allergic reactions were tested by the Center For Disease Control.
None of them had antibodies to the Starlink protein. Something had made these
people feel ill, and genetic engineered food became their scapegoat.
Not long ago, I was listening to the Boston area public radio station. An
invited commentator was presenting his opinion that modern food is
inferior to the foods of the past. He gave an example. ``Tomatoes used to taste
good, but they have now been genetically engineered so that they can be picked
while they are still green. This makes them easier to ship, but they taste like
cardboard.''
I very much doubt that this commentator had any axe to grind about genetic
engineering. But his comment was startling. There are no genetically modified
fresh tomatoes for sale! He had almost certainly never tasted one. The green
tomatoes are indeed picked green to permit easy shipping, but they aren't genetically
modified. But there was once a genetically engineered tomato offered for sale. It
contained an antisense gene so that it wouldn't rot so quickly after it got ripe.
The idea was to allow growers to ripen it on the vine and get it to the store before
it began to rot. In other words, the only genetically modified fresh tomatoes ever sold
were meant to avoid exactly what the commentator was complaining about. Consumers
loved the modified tomatoes, which were prominently labelled, and they bought all
they could get, but the company producing the tomatoes lost heaps of money because
so many tomatoes were ruined in shipping.
The commentator had gotten everything totally backwards.
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Some Future Possibilities
This section is not about reality, but speculation. What might
genetic engineering bring us in the future?
As we've seen above, there are many opponents of the technology
who imagine all sorts of catastrophes. In the hands of true mad
scientists, biotechnology could be used for great evil. New
bacteria or viruses could be developed, capable of causing
diseases which medicine could not treat. Modern nations have
abandoned germ warfare with the possible exception of a few
rogue states, but what is to prevent an individual or a
terrorist organization from such a course?
The future could also bring us improvements in our lives, or in how
our technologies impact the other beings who share our planet.
We make many useful things like plastics from oil. Someday, there won't be
much oil left in the ground and we will need to use substitutes for energy
and for chemical feedstocks. There is no reason why plastics could not be
made by plants if we could somehow engineer their genes to control the
necessary chemical pathways. In fact, plants ought to be able to make
petroleum.
Bayberries are a wild shrub, usually growing near the ocean, which bear
waxy berries. They are used to make candles which burn with a delightful
fragrance. Paraffin candles are much less expensive. They're made from
petroleum. Why could not the genes that let the bayberry make wax be
transferred into a more convenient crop plant?
Many of our medical drugs are now produced by genetically
engineered bacteria or yeasts, but could instead be produced by
genetically engineered plants. In fact, they could even be
produced in the parts of plants which are now unused, like
stalks of corn or wheat. One scientist is even working on a way
to deliver edible vaccines in bananas.
There are endangered species whose decline has nothing to do with
human exploitation. Two such are the American chestnut and the
American elm. Before the twentieth century, chestnut trees were
one of the keystone species of America's eastern forests. They were
then decimated by a fungus. Many of these chestnut trees are still alive as
roots, which still send up saplings, but they never grow to
maturity before the fungus reinfects them. Elm trees, once the most
popular shade tree lining streets of American small towns, are highly
susceptible to a different fungus, carried by a beetle. Few elm trees have
survived. But scientists in Scotland have transferred genes into elm trees
that should make them immune to the Dutch elm fungus. Why couldn't we
transfer genes that would enable the chestnut to thrive again,
so that in a hundred years this species could again enrich our
forests?
Blue jeans are made from two plants. Cotton provides the fiber and
indigo provides the color. Why not engineer the cotton plant with some
indigo genes so that it produces navy blue cotton?
Can we get wool from a plant? Can we get silk from a plant?
Citrus fruits are grown in Florida and California, where the weather
is warm. Could they be engineered to grow in Maine or Minnesota?
These are imaginary applications, and you can probably think of many
others. But there are reasons why at least some of them won't happen
soon. First, we have not learned enough, in most cases, to
successfully transfer whole complexes of genes and make them
function. We could feasibly identify every gene that helps the
horseshoe crab make Limulus Amebocyte Lysate, and every protein
involved, but that would not be enough. We need to know the whole
complex synthesis pathway, and how each chemical involved would
interact with other processes in the target species.
Second, there's simple economics. Private companies do most of the
genetic engineering. They need to be motivated by a prospect of
large future profits. They are in no hurry to develop products
for a niche market. Such products are developed, instead, by
university researchers, but they usually can't get the capital
necessary to comply with all the safety regulations.
Third, as long as the movement to frustrate genetic engineered
agriculture remains effective, investors will seek other
directions, and young scientists will choose to work on less
controversial research.
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Transgenic Products from Off the Farm
Most detergents are now made by transgenic microorganisms.
Fifteen years ago, lakes and rivers were being overloaded with
phosphates which originated as detergents. Today's detergents
are based on enzymes. Not only are they non-polluting, but they
work in cool water, saving significant energy.
Diabetics must have regular injections of insulin. The only
large quantities of insulin available used to be derived from pigs.
Insulin is a protein and the amino acid sequences of pig insulin
and human insulin are not quite identical. Diabetics had to make
do with the product available. But no longer. The gene for human
insulin was isolated and transferred to yeast, and today perfect
human insulin is easily available, and much cheaper to produce.
An even more dramatic medical improvement has affected the lives of
people with defective pituitary glands. The pituitary has been called
the body's master gland because it secretes so many hormones that control
basic body activity. These are all proteins. Such proteins used to
be available only from human corpses. Today they are made by bacteria
with human genes.
A closely related development does not involve moving genes but
recognizing them. Even very tiny amounts of DNA can be
amplified and analyzed. Since every person's DNA is
different from any other person's (except for identical twins),
the analysis of minute traces of skin, blood, hair, etc. can be
used to prove that a particular person either was or was not
involved in a crime. This technology has actually been used to
exonerate innocent people who would otherwise have been
executed, and it has even more frequently been used to convict
people of crimes which couldn't have been solved by any other
means. (DNA evidence did not persuade one California jury that
O. J. Simpson had killed his wife and her acquaintance, but it
was persuasive enough to convince another jury to punish him
with a massive civil damages penalty.)
It is even possible, although not easy, to transfer human genes
into a human being with a genetic defect. Suppose a person was
born with two defective copies of a critical gene. Scientists
can transfer a functional copy of that gene into a relatively
harmless virus related to the virus that causes the common cold.
This virus is then used to infect the patient and, with luck,
some of the virus' genes, including the all-important human
gene, can be transferred into some of the human body cells. If
the transferred human gene functions, the genetic disease is
cured. So far this kind of therapy has worked only a few times,
and in one tragic case the patient died as a result of his
body's reaction to the virus. Nobody can predict whether this
human genetic engineering will some day be able to cure genetic
diseases like diabetes, sickle cell anemia, phenylketonuria, Tay
Sachs disease, cystic fibrosis, etc. Genetic engineering has even
given us some new tools in the medical battle against the most
important genetic disease, cancer.
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Summary
The story is not over, but it is time to summarize.
Science has brought us to the point where we can transfer genes from
one species to another, so that we can change the traits of
agricultural crops. Assuming that these changes are done with great
care, we can have crops which are more productive, more nutritious,
tastier, and better for the environment. It is also possible to
proceed carelessly and do damage to the environment and to people's
health. The objective record so far is that the scientists developing
transgenic crops have been very responsible and the regulatory
agencies have been very cautious. No damage has been done to the
environment. Millions of liters of pesticides have been left in their
barrels instead of sprayed on fields, and millions of cubic yards of
topsoil have stayed on the fields instead of choking streams and
rivers. Nobody has gotten so much as a zit from eating transgenic
food.
But opponents of transgenic food have arguments against it. Some
are valid, but too many of the opponents are not content to base
their arguments on facts. They have spread lies and they have
stated facts in a way that is meant to mislead. They have also
resorted to ``direct action'', more explicitly to vandalism, and
they have allied with the United States' economic competitors to
disadvantage American companies and American farmers. Their
campaign of vilification is clearly bearing fruit. It is time
for people to stand up to this campaign by educating themselves.
Knowing a few facts serves to immunize us from propaganda.
Introduction to Genetic Engineering
Let's see what some of these agricultural applications have been
and what they might be in the future.
Rice does not contain very much vitamin A. In the poorer parts of
Asia, where rice is almost the only food of the rural population, a
vitamin A deficiency is common, leading to early blindness. Now
Drs. Ingo Potrykus and Peter Beyer, two genetic engineers, have
transferred the genes for vitamin A from other species into rice,
creating a strain of rice which is rich in vitamin A -- the
amount of rice in a typical third world diet could provide about
fifteen percent of the recommended daily allowance of vitamin A,
sufficient to prevent blindness. Now that a few plants with
this trait have been created, they are being cross bred with
other varieties of rice using conventional breeding techniques,
as has been done for centuries. Such cross breeding could
further increase the vitamin A content.
It is possible to transfer a gene from a fish to a tomato plant.
It was tried by DNA Plant Technology of Oakland, California. The
fish, an arctic flounder, can tolerate very cold water because
its blood contains a natural antifreeze. The hope was that a
tomato plant would also be cold tolerant. When the resulting
plant was tested, it was a failure. The company abandoned the
project and has no plan to try again. All the posters portray is
a just-so-story, a product that doesn't exist. In fact, no plant
product on the market today contains a gene from any kind of
animal, with one exception - there is a gene from a luminescent jellyfish used as a marker, an
indication that the gene transfer has been successful. (Images courtesy of
Steven Haddock, Monterrey Bay Aquarium Research Institute)
There is a fat green caterpillar, the tomato hornworm, that eats
tomato plants, and there is a parasitic wasp that lays its eggs
in the body of the caterpillar. The wasp larvae use the
live caterpillar for food. But why doesn't the caterpillar's immune
system attack the wasp larvae? Because the wasp has evolved a
partnership with a virus. The virus is carried by the wasp into
the caterpillar, where it goes to work changing the
caterpillar's DNA, modifying the caterpillar's immune system to
the benefit of the wasp larvae and the virus. The photo below
shows a tomato hornworm covered with the cocoons of the
parasitic wasps that grew as larvae within its body.
One argument made against transgenic crops is that they will lead to a
loss of biodiversity. It is hard to see how this can be
believed. Exactly the opposite may be expected.
Some of the genes transferred to crops have come from viruses.
GE opponents had a field day when Cornell Professor John Losey
reported that pollen from Bt corn killed the larvae of the monarch butterfly. What
fantastic publicity to herald the danger to the environment of a
GE crop. Many a child has collected a beautiful blue chrysalis
and protected it until its black and orange butterfly hatched
and flew away. The report of Dr. Losey's experiment was in
hundreds of newspapers the very next day. Two days later, the
European Union announced a moratorium on all future approvals of
genetic engineered crops because of the monarch butterfly.
In the waters off the coast of North
America there is a peculiar animal called a horseshoe crab (Limulus
polyphemus). Horseshoe crabs are regularly captured and their
blood is used to make a substance used to sterilize medical
supplies. There are certain bacteria, called gram negative
bacteria, hard to detect, but which will cause clotting in a
mixture of biological chemicals called Limulus Amebocyte Lysate
(L.A.L.), found only in the horseshoe crab's blood. Horseshoe
crabs are not yet considered an endangered species, but their
numbers have declined precipitously in recent years. Obviously
the crabs would be better off if we could copy their genes into
a convenient plant or yeast and make whatever L.A.L. we need
without bothering them anymore.
Very little fuss has been made about the non-agricultural
applications of genetic modification. Perhaps people are simply
unaware of just how many products there are, or perhaps there is
some special gut reaction (no pun intended) when the product is
something we eat.