A Report on Genetically Engineered Crops

Copyright June 2001
Revised July 2002
Charles M. Rader

This report is about two closely related subjects. One subject is the considerations for and against genetic engineering of our food. Although I will freely admit to a bias in favor of engineering, I have tried very hard to make this part of the report neutral and objective.

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, many dishonest.

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 left out most scholarly references and on the web, I used hyperlinks in place of footnotes. In this printable version, the links are replaced by endnotes, numbered [1] to [48]. I've tried to make the main flow of the report logical, but since that can be tedious, I recommend reading most of the endnotes, some of which contain material that's interesting but not vital to the flow.

I would certainly welcome your comments at rader@ll.mit.edu.

Introduction to Genetic Engineering

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[1] 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[2]; 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.

Some Early Fruits of Transgenic Agriculture

Rice with Vitamin A

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[3] 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.

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 an enzyme called phytase. Phytase 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 phytase in the grains. Dr. Potrykus hopes to be able to find a gene coding for a protein that will break down phytase when the rice is cooked.

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.

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.

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.

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[4], 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[5] in the cotton belt has declined dramatically, by over a million liters per year.[6] 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. [7] We may think of cotton as a natural material, therefore 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 thuringienses which is deadly to beetles. The gene for that toxin was used in potatoes. [8]

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.

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 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.

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.

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.

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[9] survived. If you like papaya, you can only buy the transgenic variety. Nobody can grow any other kind.

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.

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.

Building with Silk

Silk is composed of two proteins, fibroin and sericin. The gene for fibroin has been transferred from a silkworm[10] 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.

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.

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.

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.

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.

Biological Pest Controls

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 will be broken when predatory insects, genetically engineered to tolerate the pesticide, become available.

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 and, when necessary, using pesticides. Farmers can buy such insects as ladybugs, praying mantids, lacewings and parasitic wasps.

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.

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.

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.

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[12] 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.

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.

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.

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.

Monkeying with Mother Nature

Some people think that this is an enterprize 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[13], 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.

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[14] 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 mutations and select for them. 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[15] for plant breeding, 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[16]. 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[17], 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[18]. So it seems to me that the issues of food safety are being better managed for genetic engineered foods than for conventional foods.

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[19].

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[20] 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[21].

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.

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 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. It is not so easy 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.

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[22] 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 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.

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.

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.

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.

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.

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[23].

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.

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[24]. 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. 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 numerous other varieties of potatoes, bred to be eaten, but 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.

As another example, perhaps some of you in August 1999 read an op-ed article in the Boston Globe 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[25]. 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.

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. The problem was that the health food industry, which has avoided many food safety regulations, manufactured and sold contaminated tryptophan, which made people sick. The responsible company, Showa Demko Ltd., genetically engineered bacteria to make more tryptophan than needed for their own life cycle. But Showa Demko tried to cut costs by leaving out an important purification step. The problem had nothing to do with 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 would have been detected by elementary chemical tests, even without animal experiments. This would make a very good argument for more scrutiny of the health food industry. Presenting it as an indictment of transgenic food is a huge distortion.

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 completely 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[26] of genetic engineering. They are not!

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[27] used as a marker, an indication that the gene transfer has been successful. (Images courtesy of Steven Haddock, Monterrey Bay Aquarium Research Institute)

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 duram 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''.

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.

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.

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[28].

Actually, India had not yet licensed transgenic cotton[29], but there are 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.

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[30] 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'', is a rather complex genetic engineering technology. Several different control genes are transferred into the target crop variety. When they all work together[31], the plant produces infertile seeds. The crop is edible, but its seeds will not germinate. But the genes do not all work together unless the seed from which the plant is grown is treated with an antibiotic, tetracycline. As long as the parent seeds are not treated with tetracycline, the next generation's seeds are fertile and can 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.

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[32]. 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[33] 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.

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.

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.

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. Nobody knows whether the amount of vitamin A can be increased by selective breeding. After correcting Ms. Shiva's exaggerations and errors, today's best strain of golden rice is still only able to provide about 15% of the RDA, enough to prevent blindness but far from an optimum.

Another question is whether the third world consumers will accept golden rice. There is some reason to think not[34].

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 has 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.

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[35], 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.

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[36] 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[37] 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.

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.

crossing over

Plants and animals have two of each gene, on separate but similar chromosomes, analogous to having two copies of the document. The two copies are usually slightly different. By analogy, if the document were The Lord's Prayer, one copy might read The Lord is my shepherd! I shall not want. The other copy might read God is my guide! He provides for me. In sexual reproduction, the two documents are sliced apart and put back together, so that they might read The Lord is my guide! He provides for me. and God is my shepherd! I shall not want. This process is called crossing over. This happens in the sex cells of both parents and then the offspring inherit one ``document'' from each parent. Crossing over is a major source of genetic variability. Sometimes, however, it produces the same kind of nonsense as in the example ``don't be happy! drink the water!''.

transposons

Genes are arranged on the chromosome in order but many genes make a habit of jumping to another part of the chromosome. They are routinely snipped out of the DNA and put back in a different place. These jumping genes are called transposons. By being moved to a different part of the DNA, the functional expression of a transposon changes. A familiar example of a transposon is a gene that determines the color of the kernels of Indian corn.

viruses

Many viruses insert their own DNA into the host's DNA document, where it gets copied and becomes part of the genome[38]. More than half of the DNA in the human genome originated as invading viruses. These viruses can carry useful genes[39] from other species into the infected animal or plant. Many human genes originated in other species by this mechanism.

mutations

With billions of letters in a DNA document, there are always a few copying errors, called mutations. A mutated gene has a changed meaning. It may specify a slightly different protein, or it may switch another gene on or off at a slightly different time. These changes are usually harmful, but tolerable, especially when we have two copies of a gene and one is unchanged. Occasionally a mutation is either deadly or beneficial. According to the theory of evolution, all of our genes originated, in the distant past, as mutations of other genes, a completely random process.

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.

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[40]. 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. shaky the science can be, which genetic engineering opponents are willing to use.

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.

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[41] 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[42]. 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.

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[43]. (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?

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[44]. Hybridization with wild plants is a concern, but it is a managable concern.

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.

The Monarch Butterfly Story

GE opponents had a field day when Cornell Professor John Losey reported that pollen from Bt corn killed the larvae of the monarch butterfly[45]. 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.

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[46].

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.

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.)

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.

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.

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.

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.

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.

In the waters off the coast of North America there is a peculiar animal called a horseshoe crab[47] (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.

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.

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[48].

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.

Part III - ENDNOTES

[1] Genetic Code - Ingredient List for Making Protein

The letters of the DNA code are like beads on a string. There are four types of chemical beads with chemical names adenosine, guanine, cytosine and thymine, usually abbreviated A,G,C,T. Two such strings are almost always twisted together with letters on one string paired to letters on the other string in a definite way. The A always pairs with the T, and the C always pairs with the G. That means that if one string reads from left to right, say, ...AAGTACCTGAAC..., the other must read ...TTCATGGACTTG... Either string has the recipe for copying the other. When a cell divides, each DNA strand can act as a template to build a new complementary strand and the cell ends up with two DNA molecules where it started with only one.

These strings are extraordinarily long, billions of letters long in complex organisms. Even a simple virus will have about 10,000 letters in its DNA recipe book.

The strings are divided into sentences called genes, and there are two types of genes. One type acts like a switch. The other type is a list of ingredients for making a protein. The switches work by either letting a nearby gene be read, or by blocking it from being read. There are lots of different types of switch and lots of different control strategies for turning genes on or off, but the method of reading a list of ingredients and constructing a protein is universal. All living things use the same process.

It begins with a molecule called RNA which, like DNA, is composed of four types of chemical pieces like beads on a string. The RNA molecule is actually put together alongside the DNA and a copying enzyme copies the DNA letters one by one to build the RNA molecule. There is a particular DNA letter subsequence that means STOP COPYING HERE. Then the RNA molecule, completed, drifts away from the DNA and enters the cytoplasm, the part of the cell where proteins are built and used. (There are other types of RNA. The kind we've just described is called messenger RNA .)

In the cytoplasm, the messenger RNA attaches itself by one end to a miniature factory called a ribosome. The job of the ribosome is to build a protein from the ingredient list brought to it by the messenger RNA.

A protein is also a long molecule like a string of beads. Unlike DNA and RNA, which are each built from four types of beads, protein strings are built from twenty different kinds of beads. These are called amino acids. Each of the many different kinds of protein has its own unique order of amino acids. There are always plenty of these amino acid ``beads'' floating around in the cytoplasm. The task of the ribosome is to snatch them up in the right order and build the string. The right order is determined by the letters making up the messenger RNA, but since that is just a copy of the DNA, it is ultimately the DNA that stores the list of ingredients of a protein.

The correspondence uses a three letter code. That is, AAA specifies one amino acid, TAC specifies another amino acid, etc. With a three letter code of four possible letters there are sixty four possible combinations. The ribosome needs twenty combinations to specify that the next amino acid on the chain is one of the twenty types. Therefore more than one triplet can stand for each amino acid.

The assembly works like this. The ribosome starts with an attachment point which is an unusual kind of amino acid never found in completed protein molecules. It then reads the first three letters of the messenger RNA, finds the appropriate amino acid and attaches it. There's now a chain of length two. The ribosome then moves forward three letters along the messenger RNA and pushes the oldest end of the amino acid chain ``out the back door''. Now it's ready to pick up the amino acid specified by the next three letters of the RNA, attach it to the chain, push the oldest end of the growing amino acid chain out, and so on. In this way, a very long chain of amino acids is constructed using the ingredient list carried to the ribosome by the messenger RNA. While the long chain is dangling off the ribosome, the unusual amino acid at its oldest end gets removed, so it's never part of the final chain.

The process ends when the ribosome reaches the end of the messenger RNA (or when it reads a three letter STOP code). Then the messenger RNA and the just completed amino acid string drift away into the cytoplasm. The RNA can be reused by other ribosomes to make other identical amino acid chains, over and over until it gets broken up.

Now we've described the amino acid string as if it were a long thin molecule, but in actuality, it curls itself up in a complex way, depending on the exact sequence of amino acids along its length. Usually the string ends up roughly spherical, with bumps and crevices uniquely determined by the amino acid sequence.

The folding up is entirely automatic. Specify the sequence of amino acids along the string and the shape of the protein is determined, but in a complex way. Some of these amino acids are attracted to one another. Some are attracted to water, so they usually end up on the outside of the protein. Others are water repellent and usually end up on the inside. Often two or more of these chains assemble together. For example, hemoglobin is formed from two chains of one type and two chains of another type. This assembly is also automatic. Once the DNA has encoded the ``parts list'' of a protein, the rest of the design is automatic.

The function of the protein is determined by its shape. A few proteins are structural, like keratin, used to make hair and fingernails strong. A few, like insulin, are used as signaling molecules, otherwise known as hormones. But by far the most important function is to serve as enzymes.

For nearly every chemical transformation that happens in a living cell, there is an enzyme that has just the right shape to either accelerate the reaction or stop it. An enzyme is a catalyst. It makes chemical reactions that could happen actually happen.

Consider a zipper. The two halves of a zipper, when separate, could come together and stick. But it requires the patience of a saint to make it happen by pushing and prodding. That's why zippers come with a sliding piece that has just the right shape to bring the two sides of the zipper together in just the right way that they stick. The slide of a zipper functions mechanically the way an enzyme functions chemically. Other enzymes can make a molecule break apart, just like the slide piece can make the joined zipper come apart when we slide it in the reverse direction. Still other enzymes can move a group of atoms from one molecule to another. Almost any chemical reaction that is possible can be helped to happen millions of times more rapidly if the right enzyme is around.

If the slider could run off the end of the zipper, it could be used to zip together another zipper, and another and another. We don't let the sliding piece of the zipper run all the way off the end of the zipper, but an enzyme, on the other hand, is free to float away and encourage other chemical reactions of the same kind.

To summarize all this we have

1. DNA codes a list of protein ingredients in a three letter code.
2. Messenger RNA copies the coded sequence and carries it to a ribosome.
3. The ribosome assembles the twenty kinds of amino acids into a chain as specified by the messenger RNA.
4. The protein curls up into a unique shape automatically.
5. If the protein is an enzyme, its shape is just right for making certain kinds of molecules come together and react, or for making a certain kind of molecule split apart.

DNA tells ribosomes how to build proteins and the proteins tell the cell how to do all the chemistry it needs to live.

There's an exception to the rule that every living thing uses the same method to build its proteins. In living things more complex than bacteria and viruses, between the time that the messenger RNA gets copied off the gene and the time it gets used by the ribosome, it gets changed. Some of the letters get snipped out of the sentence, making it shorter. That makes it a little bit tricky to predict the amino acid sequence of a protein from the ACTG sequence of its gene. Nobody knows why cells use this inefficient way of coding the ingredients list of a protein.

[2] What's a Chromosome?

A chromosome is a very long DNA molecule which contains hundreds or thousands of genes as well as some specialized protein molecules which hold it in shape, etc. In organisms more complex than bacteria, the chromosomes are usually paired, so that each gene is represented twice -- except that the two paired chromosomes could have slightly different genes.

It has long been possible to determine the order of genes on the string using an extraordinarily laborious method, at least for genes whose function is known. The idea is that characteristics that tend to be inherited together are coded by genes that must be close together on the same chromosome, and characters that are inherited more or less independently are controlled by genes that are far apart, or are on different chromosomes. Scientists made rough genetic ``maps'' of simple organisms by studying millions of matings.

The favorite test animal for these experiments was the fruit fly, Drosophila melanogaster. It breeds very quickly, requires little food and little space. You don't need much complicated or expensive equipment to do experiments with fruit flies. They also have a most remarkable and useful peculiarity. In the salivary glands of the fruit fly, each chromosome is not a single DNA molecule, but hundreds or thousands of identical DNA molecules packed together. These giant chromosomes can be seen under a microscope. They show light and dark bands that help to locate the individual genes very precisely.

Today we can make exact maps with much less work using modern biotechnology methods. The complete map of human genes was recently finished. There are also complete genetic maps known for about a dozen other species, including E. coli bacteria, tiny flatworms, rice, and fruit flies.

The DNA of bacteria are not packaged in chromosomes. Instead the long string of DNA letters closes on itself to form a circle, with no beginning or end.

[3] Beta Carotene, a Source of Vitamin A

There is no single gene for making vitamin A. There are genes that encode enzymes that facilitate the chemical steps that build vitamin A.

Humans can either get vitamin A directly from food, or the body can make it from certain other substances found in food, called precursors. They are soluble in cooking oils and they tend to be yellow or orange. The best precursor is beta carotene, because our bodies can make two molecules of vitamin A (retinol) from each molecule of beta carotene. The transgenic rice contains beta carotene. The grains have a noticeably yellow color, which has given it the nickname golden rice.

Rice already has genes which make enzymes that control the chemical pathway for beta carotene synthesis. The plants make beta carotene in the leaves and in the stems, but they make none in the part of the plant which people eat, the endosperm, the white part of the grain. What the plants needed were some genes which could complete the beta carotene synthesis pathway in the endosperm.

Three genes were used, including two from a daffodil, a logical species to choose if you want to make a yellow pigment like beta carotene.

Here's an explanation of molecular diagrams:

Organic chemists use diagrams like those above to describe molecules. Since some organic molecules are very complicated, they use a few standard shortcuts to keep the diagrams simple.

The different kinds of atoms are indicated by one or two letters, such as

Element	Symbol	Element	Symbol
Carbon	C	Oxygen	O
Hydrogen	H	Nitrogen	N
Phosphorus	P	Sulfur	S
Chlorine	Cl	Iron	Fe

Groups of atoms are indicated by running the letters together -- e.g. OH stands for an oxygen atom and a hydrogen atom in a group. If a group contains several atoms of the same type, they use a subscript -- e.g. CH₃ means a carbon atom and three hydrogen atoms.

Some of the carbon and hydrogen atoms are not written in, but a straight line segment indicates a bond between atoms, so we know that the atoms are at both ends of each straight line. Usually those atoms are carbon, but sometimes they're hydrogen. Here's how we tell. Each carbon atom makes four bonds. So where four lines meet there's a carbon. Where fewer than four lines meet, there's also a carbon and there's a hydrogen atom for each missing line.

To illustrate how this works, look at the diagram for vitamin A. On the extreme left there's a hexagon. Since it has six corners, there are six carbon atoms at those corners. Three of the corners have four lines each so those corners have only carbon atoms. The other three corners have two lines each so those corners each have a carbon atom and two hydrogen atoms. Looking at the middle of the chain, there are corners with four lines, which must each have a carbon, and there are corners with three lines, which must each have a carbon and a hydrogen. Finally there are five attached CH₃ groups and one attached OH group.

The molecule is connected up as shown, but it isn't flat. The diagram doesn't even try to show the shape of the molecule, only how its atoms link to one another.

[4] Bacillus Thuringinsis

In 1901, a Japanese scientist investigating diseases of silkworms discovered that one such disease was caused by a previously unknown kind of bacteria, Bacillus thuringiensis. B. thuringiensis is commonly found in soil where it forms tiny spores which can persist in a dormant state indefinitely.

The strain of Bt bacteria first identified in Japan was capable of killing a variety of butterflies and moths, but only in their larval (caterpillar) stage. The scientific name for butterflies and moths is Lepidoptera.

It took another fifty years before scientists figured out how Bt kills caterpillars. When a caterpillar eats a leaf covered with spores of the bacteria, these spores revive in the insect's gut and begin to grow and reproduce. As a normal part of their life cycle, they produce a crystalline protein, called Cry. Cry molecules have just the right shape to bind to cells lining the insect's gut. Cry kills those cells. Unable to digest its food, the caterpillar soon dies. If an insect has a different kind of gut lining cells, the Cry protein does not affect it. The protein is just digested like any other protein. That's why Cry is highly specific, harming only caterpillars.

As early as 1938, a commercial preparation of spores of B. thuringiensis was sold as an insecticide. It was not terribly effective, for several reasons. Caterpillars often eat only the bottom surface of a leaf but sprayed Bt spores tended to reach only the upper leaf surfaces. There, they were usually washed away by the next rain. But Bt had one huge advantage over stronger insecticides. With insecticides poisonous to humans, the farmer can't harvest the crop for several weeks after the last application. Bt can be used at any time.

Because the Cry protein is produced by a natural bacterium, it is a boon to organic farmers. A rule of the organic movement is that no artificial chemicals may be used, either as fertilizers or as pesticides, but Bt is allowed. (It's not clear just what makes a chemical ``artificial''. Organic farmers are allowed to use mineral oil and on some crops they use copper sulfate, and of course, many chemicals added to food during processing are unambiguously artificial.) But only a small part of the Bt pesticides are used in organic farming. Their largest use is in forestry.

As Bacillus thuringiensis was studied by scientists, many strains were discovered which produced slightly different forms of the Cry protein. Since the different proteins have different molecular shapes, they may fail to bind to the gut cells of one kind of insect but bind to the gut cells of another kind. One strain of Bt produces a Cry protein that kills some beetles, but not caterpillars. Another strain's protein kills a different kind of beetle. There is even a strain whose toxic protein kills mosquitoes. None of these proteins harm birds or mammals.

As we know, proteins are synthesized under the direction of genes, so each of the many different Bt toxins must require its own gene. It turns out that the genes for the Cry proteins are not part of the B. thuringensis' main chromosome. There is a very small DNA molecule called a plasmid, a chromosome with only about a dozen genes, and the Bt toxin genes are found on the plasmid. The different strains of B. thuringiensis have approximately identical chromosomes but slightly different plasmids. Some of the commercial preparations of Bt spores have been genetically engineered to have the genes for several different toxins so they can control both caterpillars and beetles.

There is a deadly variety of Bacillus called anthrax. It is also a spore forming soil bacterium but it can thrive in the blood of many mammals, including humans, and it produces a toxin which is soon fatal. The main chromosome of the anthrax bacteria is essentially identical to the chromosome of B. thuringiensis. Only its plasmid is different. It is only a matter of semantics whether anthrax bacteria are considered a different species or just a different strain of B. thuringiensis.

[5] Cotton Pesticides

Pesticides replaced include endosulfin, methonyl, profenos, thiocaarb, and various pyrethroids.

[6] Cotton Pests

The boll budworm, pink bollworm and tobacco budworm, together, account for only about a quarter of the losses of cotton crop. If further gene transfers were developed to control other insects, significantly more pesticide use could be avoided. Although cotton farms occupy only 5% of US farmland, these farms account for about half of all pesticides used in the United States.

The best known cotton pest is the boll weevil. Weevils are beetles. Although the Bt toxin presently produced by Bt cotton doesn't affect weevils, there are other Bt toxins that would kill it, occurring in other natural varieties of Bacillus thuringiensis. Meanwhile research is underway to discover how to transfer the genes for other pest specific toxins.

[7] The Tale of the Fresh Water Mussels

Fresh water mussels are innocuous creatures that live on the gravelly bottoms of streams. They are bivalves and the insides of their shells have a pearly appearance. They are filter feeders, constantly pumping water through their bodies and filtering out nutrients. In this way they are an important factor in keeping water clean.

In the nineteenth century, America's freshwater mussels were nearly driven to extinction. They were collected in vast numbers so that their shells could be made into buttons. They were ultimately saved from extinction when chemical engineers developed cheap plastics.

Today mussels are again threatened, this time by the heavy use of pesticides on cotton fields. It would be nice if they were once again saved from extinction, this time by genetic engineers.

[8] Potatoes of Prince Edward Island

Potatoes are also responsible for pesticides getting into the environment. For example, in Prince Edward Island, which grows about 1/3 of Canada's potato crop, there are fish kills following almost every rainstorm during the potato growing season, caused by pesticides aimed at controlling the Colorado potato beetle.

PEI farmers have been reluctant to use transgenic potatoes. Activist groups who oppose genetic engineering have put pressure on the major food processing companies to not buy transgenic potatoes, or be picketed. Some major potato customers, like MacDonalds, have caved in to this pressure.

Prince Edward Island is far away and its frequent fish kills are not reported in the US press. It is easy for these activists to call themselves environmental advocates, although their campaigns are a direct cause of an environmental hazard.

[9] Hawaii's Papaya and the Ringspot Virus

Papayas are Hawaii's second largest crop but are subject to infection by the ring spot virus. When this virus appeared on the island with the most papaya farms, nothing would control it and plants infected simply died. The virus can also infect native Hawaiian plants, although it does them little harm. So there was always a source of reinfection.

At first, the problem was confined to the one island, so growers responded by raising papayas on another Hawaiian island. But the ring spot virus appeared there as well. Soon all the Hawaiian islands were affected. Agronomists expected the Hawaiian papaya industry to disappear completely in a short time.

Salvation came from Cornell University genetic engineers Dennis and Carol Gonsalves. They copied the gene for the ring spot virus' coat protein into the genome of a papaya. Coat protein, without the accompanying virus DNA, is harmless, but the modified papayas produce the coat protein and the plant's own immune system becomes primed to fight it. It's the same idea as we humans use to protect ourselves by vaccination. Drs. Gonsalves' transgenic papayas have thrived and are now the only kind of papayas grown in Hawaii, except for a few surviving plants whose fruit is exported to Japan. The Japanese have not yet allowed the import of transgenic papayas.

[10] The Story of Silk

Silk was discovered in China at least 4500 years ago. A Chinese legend has it that the emperor Huang Di (the yellow emperor) accidentally dropped a silkworm cocoon in his tea, and observed its shining fiber as it began to unwind.

The silkworm is the caterpillar of the moth Bombyx mori. It is a completely domesticated insect. There are no wild silkworms and silkworms can't live without human care.

The silkworm caterpillar grows to about three inches long on a diet of nothing but white mulberry leaves. Then it spins a cocoon about itself and metamorphoses into an adult moth. The adults mate, lay eggs and die in just a few days.

The silk is a continuous thread, as much as half a mile long, which makes up the cocoon. The silkworm has a pair of glands which produce a liquid form of the protein fibroin. Fibroin emerges from a silk gland as a continuous fiber coated with the other silk protein, a sticky substance called sericin. The two glands form two fibers which are then spun together by a specialized organ, the spinneret.

The collected cocoons are put into very hot water, which, of course kills the silkworm. A single thread is prized loose from the wet cocoon and unrolled. The best quality silk is unrolled by hand. When the whole cocoon has been unrolled, the little cooked silkworm provides a snack for the worker.

Silkworms played a big part in medical history. The Chinese had had a monopoly on silk production for millennia, but in the nineteenth century, French producers got a few cocoons and established a local silk industry. Soon, however, the silkworms began dying of an unknown disease. The silk raisers turned for help to Louis Pasteur, who was able to discover that the disease was caused by bacteria, and prescribe the sanitary procedures that saved the French silk industry. That convinced Pasteur that many diseases were caused by bacteria. It marked the beginning of the modern age of medicine.

It was another scientist studying silkworm diseases, Dr. Ishiwata Shigetane, who first identified the bacterium Bacillus thuringiensis, which is the source of Cry protein, the Bt toxin which is now made by many insect resistant transgenic plants.

Japanese scientists have given silkworms a gene for luminescence. They produce silk that glows in the dark. Although this might be a useful product, the scientists' real goal is to be able to replace the luminescence gene with any useful other gene they choose. If a transgenic silkworm doesn't produce light, the new gene must have successfully replaced the luminescence gene.

[11] Life Cycle of a Fern

The plant that extracts arsenic is a fern. It ought to be possible to plant this kind of fern in the arsenical soil and harvest the grown plant. The plant material could be trucked to a waste site. Any arsenic in the plant is no longer in the soil, and a few years of this treatment should decontaminate the soil. Unfortunately, ferns are not able to grow in most soil conditions.

The life cycle of a fern is quite interesting. We are used to seeing the green plant with fronds, which biologists call a sporophyte, and it looks rather like many other plants. But its method of reproduction is quite different from more familiar plants.

Like ordinary plants (and animals), each cell of a fern has two of each kind of chromosome. Biologists call it diploid.

The underside of its leaves can bear spores, but spores are not like seeds. Each spore is more like a grain of pollen than like a seed because it has only one of each kind of chromosome instead of two. Biologists call that haploid. Pollen, ovules, sperm cells and egg cells are haploid cells. Pollen and ovules come together to form a seed which has two of each chromosome, just as sperm and egg come together to form an embryo whose cells have two of each chromosome. But a successful spore grows into a complete multicellular plant called a gametophore , and each cell of the gametophore is also haploid. We usually don't notice it because it is usually very small. It doesn't look anything like a fern.

The gametophore lives its brief life and when conditions are right, it produces reproductive cells, also haploid, called gametes. Some gametes can swim like sperms and others, eggs, stay put. Eventually a sperm gamete can meet an egg gamete and they will fuse. The result of the fusion is now a diploid cell -- it has a pair of each kind of chromosome, one from each gamete. It is the fused gametes that grow to become a fern (diploid).

Imagine what humanity would be like if every sperm cell could grow into a complex individual and have numerous children of its own, and if those children could mate, like a sperm and an egg, to become a human being. Our children would not resemble us at all, but our grandchildren would. It seems like it would be a good plot for a science fiction story.

The gametes must swim so at this point of the fern's life cycle, it needs a watery environment. Ferns cannot grow in dryish soils. So they wouldn't be suitable to decontaminate dry soils.

[12] Allergens

Almost any food can contain an allergen, a substance that causes an allergic reaction for some people, but doesn't affect most other people. Most food allergies come from eating a few common foods, principally peanuts, tree nuts, shellfish, eggs, wheat, corn and soybeans. An allergen doesn't have to come from something you eat. It might be something you touch or something you breathe, like pollen or even dust. Some allergens affect only a few people.

If you are one of the unfortunate people who is allergic to something you have eaten (or touched or breathed) it is important to discover which substance caused the problem. It is relatively easy to test a suspected allergen using a skin patch. If the allergen is not on the usual list of substances, discovering what caused the reaction can be quite hard.

Some proteins are allergenic. If a protein causes an allergic reaction, it is reasonably likely that a different protein with a similar amino acid sequence will also cause a similar reaction in the same person. Conversely, a protein whose amino acid sequence is not similar to any of the known allergens is not likely to be an allergen.

[13] Leviticus 19:19

Leviticus 19:19, from the Good News Bible, reads Obey my orders. Do not crossbreed your cattle. Do not plant two kinds of seed in the same field. Do not wear clothing made from two kinds of fiber.

The King James version of the Bible has Ye shall keep my statutes. Thou shalt not let thy cattle gender with a diverse kind. Thou shalt not sow thy field with mingled seed. Neither shall a garment mingled of linen and woollen come upon thee.

If this biblical law is taken to prohibit genetic engineering, it would have to also be understood to forbid conventional hybridization, especially since the Leviticus text precedes genetic engineering by at least 2500 years.

[14] Essential Amino Acids

There are eight essential amino acids -- isoleucine, leucine, lysine, methionine, phenylalanine, threonine,tryptophan and valine. Our bodies need twenty different amino acids, but we are able to make the other twelve kinds from these eight, which we must get from food. Corn is rich in methionine, so vegetarians often combine corn and beans to get a balanced protein.

[14] Irrational Difference of Regulation for Different Breeding Techniques

There can be no disagreement that even a single gene change can possibly make a big difference in a plant's properties. Centuries ago, a wild type carrot changed one gene and became the orange vegetable we know. Wild carrots are yellow. It is certainly equally possible for a gene change to make a crop less satisfactory, even poisonous. Normal sexual crossings mix up thousands of genes, so many that there are probably no two plants on earth with exactly the same genes except for clones. If we insisted on perfect safety, we would need to chemically analyze an apple from each apple tree, a tomato from each tomato plant, etc. Only centuries of experience has convinced us that the really dangerous effects of genetic mixing are vanishingly rare, so rare that we do essentially no safety testing of crops developed by crossbreeding.

But there are other more violent ways to change a genome. Early in the twentieth century it was discovered that x-rays or certain chemicals could make genes change at random. Almost all of these changes were harmful, but a few were not. Breeders were glad to get a few extra mutated kinds of genes to subject to the old fashioned crossbreeding. The United Nations Food and Agricultural Organization has identified over two thousand different varieties of crop which were developed using chemicals or radiation. Are they safe? Here we don't have centuries of experience to guide us. Each new mutation has its own story, not to mention all the ways it can be in combinations with other genes. Of course, breeders understand this and they do some elementary testing of their newly developed crops. They are motivated to be sure that the crops will be accepted in the market place. But the testing of mutated crops is not mandatory, and there are no standards.

Another violent way to change a genome is to double up its chromosomes. This can be accomplished by treating the fertilized ovum with a chemical called colchicine. Even one extra chromosome can make a big difference in the phenotype. The human genetic disease called Down's syndrome (formerly called mongolism) is the result of just one extra chromosome out of the normal human complement of 46. But again, breeders are glad to get the extra variation to drive their selections. Dozens of crops and many decorative plants were created this way.

The rules for testing of doubled chromosome varieties are the same as for mutated varieties -- there are none.

It has to be understood that when plants are developed by these violent techniques, we have no idea what genes are involved, what proteins they make, what chemical transformations these proteins facilitate. Suppose we wanted to recommend some tests for a particular mutated crop. Where would we start? When would be think we had tested enough, and why?

Contrast this with genetic engineering. It makes a change in, usually, one gene. That gene is understood in complete detail. The genetic engineer knows the ACGT sequence of his gene, and what turns it on or off. The engineer knows where the gene is placed in the chromosome. He or she knows what protein it synthesizes and knows that only that one extra protein is going to be made in the transformed crop. He knows what chemical reactions the protein controls.

This doesn't mean that the genetic engineer knows everything. Living things are just too complex to make perfectly reliable predictions. But the genetic engineer can easily plan a rational set of tests to assess the safety and success of the transformation. The safety of the new protein by itself can be assessed even before the transformation. Its effect on the rest of the life process of of the plant is assessed by comparing the chemical composition of the transformed plant with its precursor. It is just simply easier to test for the effects of a change when you know what you changed.

Why are genetic engineered crops tested so much more thoroughly than mutant crops? Because it's easier.

[16] Harmful Celery

It was a variety of celery which contained high levels of psoralens, which become irritants when activated by sunlight.

[17] Aflatoxin

Aflatoxin is a potent carcinogen. The fungus (genus Aspergillus) that secretes aflatoxin enters the plant, usually, through the wounds left by an insect pest, since most plants have a hard outer layer that acts as a barrier to fungi. Once inside the plant, the fungus can reach all parts of the plant, including its seeds. Our grain supply is routinely screened to detect and eliminate aflatoxin, but it is a serious cause of illness and death in developing countries which have fewer food safety regulations. Some plant scientists are trying to develop transgenic corn with a gene for an enzyme which breaks down aflatoxin.

[18] How Foods Cause Illness

There are three common things in food which can make people sick: allergens, natural toxins, and spoilage.

Allergens must be substances recognized by our immune systems. For most people, they cause no trouble. But for a few people, the immune system can vastly over-react to some particular substance and flood the body with histamine. Histamine in small amounts is necessary for many body processes, but in larger amounts it is a poison, which causes rashes, vomiting, abdominal cramps and diarrhoea.

The human immune system is remarkable. There are millions of substances which it might need to recognize - the surface proteins of bacteria and viruses. But the body can't spare a gene for each of these proteins. There just aren't that many genes. Instead, the mammalian immune system uses only a few very complex genes. In the embryo stage, a large number of specialized immune system cells are produced and each of them makes a few random cuts in the DNA of its own copies of those genes and reassembles them. So, any one of the immune system cells has only a few genes devoted to recognizing a foreign substance, and can recognize only one substance, but there are many immune system cells and they can each recognize their own substance.

Then follows a training period. The immune cells that recognize the body's own proteins are permanently disabled. The others are kept around, but remember, for each substance there are only a few cells that can recognize it.

Now suppose a foreign substance gets into the blood stream for the first time. A few immune system cells find it and recognize it, but they are too few to combat it. Instead, they let other body defenses take responsibility, but those particular immune system cells reproduce, increasing their numbers so that the next time the substance is encountered they are ready for a massive response.

An allergy is a malfunction of this system. The substance recognized is a harmless food material, but the immune system treats it as it would an invading microbe, and it responds out of all proportion to the amount of allergen present.

So there are two characteristics of an allergic response. First, it must be something that you have been exposed to before. Second, your response doesn't depend much on the dose. A little is as bad as a lot.

If you suspect that you are allergic to something, an allergy specialist can check easily. A patch with a tiny quantity of the suspected allergen is placed on the skin and if there is a histamine reaction, you have found the allergen. You had best avoid coming in contact with it from then on.

The second and third ways food can cause you illness are due to toxins. There are toxins naturally present in the particular food, and there are toxins that don't belong there, caused by bacteria, fungi, etc.

Practically no food is entirely nutrients. Most plants produce poisons that help fight off insects or make the plant unpalatable to browsing animals. For example, celery contains psoralens, potatoes contain solanines and beans contain lectins (which are mostly destroyed by cooking - raw beans are very toxic). Even something essential to life can be a poison if there's too much of it. The histamine which causes allergic reactions is the same histamine the body needs for normal life processes, but too much of it will produce the same effect whether it is an allergic reaction or a food ingredient. Most fish, cheese and wine contains some histamines.

The main difference between a toxin and an allergen is that a toxin has an effect proportional to the dose. If a milligram is bad, ten milligrams are ten times as bad.

Our bodies work to get rid of toxins. A few of them, like alcohol, can be transformed by special enzymes into harmless or even useful substances (which is why alcohol has calories). The liver is the organ specialized to transform toxins into useful substances. But if you overload the liver it will take a long time to detoxify and you will be sick until it has finished. Small amounts of these toxins will not be noticed.

With other toxins, the body's defense is to make the toxin water soluble and flush it out of the body as fast as possible. A particular protein called cytochrome P450 is a sort of detoxifying generalist. It can bind itself to a wide variety of small molecules and make them water soluble. The P450-toxin complex is then carried to the kidneys and becomes a component of urine.

Our bodies deal with toxins caused by spoilage in the same way. But, of course, they can be more dangerous because there can be rather a lot of them. They can also include some very nasty toxins indeed. We can process 10 milligrams of solanine and hardly notice it, but 0.000000008 milligrams of botulin will surely kill us.

Many people worry about residues from agricultural pesticides. In most cases these are toxins which the body can deal with exactly the way it deals with other toxins. Regulations regarding pesticide residues on food are meant to assure that the toxic load of pesticides is negligible in comparison with the natural toxin load present in the food.

Of course, any pesticide residue is worse than none at all. But it wouldn't make sense to avoid a tiny amount of pesticide residue in exchange for consuming a larger amount of some ``natural'' toxin.

[19] Origins of Common Crops

Almost everything grown for food in the United States originated somewhere else, as a wild plant. In many cases, the wild plant has been so changed by breeding that it would be difficult to recognize.

Would you have suspected that broccoli and cauliflower are both derived from the same wild species? How about brussels sprouts and kale? In fact all four of these crops, along with cabbage, have the same ancestral species, Brassica oleracea, a wild European plant.

Wheat came from the Middle East, corn from Mexico, potatoes from Peru, soybeans from China, sugar cane from New Guinea, oranges from India.

The rest of the world has borrowed biodiversity just as freely. Imagine Indian food without hot peppers, but they came from Mexico. Imagine Italian food without tomatoes, but they came from South America. Imagine French desserts with no strawberries. There are wild strawberries growing in France, but the French and everyone else enjoy a domesticated strawberry produced by crossing two species, one from Chile and one from southeastern United States. Africa's largest crop is cassava, but it comes from the Amazon River basin.

In China in 1982 I visited a temple that was represented to me as 700 years old. The design cast into its huge bronze doors was unmistakably corn! I asked how there could have been corn in China seven hundred years ago when Mexico and Asia had not known of each other until 1500. My hosts were surprised because they thought that corn had always been grown in China. Certainly they've had popcorn long enough to have developed a unique way of popping it. The kernels are put into two steel hemispheres which are screwed together to form a sphere and put into a fire. When the sphere gets hot enough, it's removed from the fire and taken apart (with asbestos gloves). The sudden change in pressure pops the corn kernels instantly.

[20] Pollen that Strayed

Transgenic plants have been found growing where no transgenic plants were sown. The most common such plants have been canola and sugar beet. Both species have wild relatives which grow as weeds. For both these species, the possibility of gene transfer to wild plants was considered during the regulatory review process and nobody could think of any reason why such gene transfer would be detrimental to the environment. The transferred gene confers resistance to the glyphosate herbicide.

A Canadian farmer, Mr. Percy Schmeiser, was sued successfully by Monsanto, for growing its patented glyphosate resistant canola without paying the company any licensing fee. Mr. Schmeiser's defense was that the crop had appeared in his field because pollen from nearby transgenic crops had fertilized his plants one year, and that he had saved seed from those canola plants for the following year's crop. Testimony in court cast doubt on his claim because the nearest field where transgenic canola had been planted was five miles from his farm, and because almost every plant in his field was the transgenic variety. The judge decided that Mr. Schmeiser knew that his plants were Monsanto's patented variety, so that it didn't matter how he obtained them.

After Starlink corn was found in the human food supply, the gene for Cry9C was found in cornfields where Starlink corn hadn't been knowingly planted. It is possible that the company supplying seeds for these farms had mixed a few kernels of Starlink in the seed sold to these farms. It is also possible, although unlikely, that the plants grown for seed were pollinated by Starlink corn grown somewhere nearby.

[21] Evolution of Resistant Insects

[22] The First Genetic Engineer

The first genetic engineer was a scientist named Fred Griffith. In 1928, he was studying how Streptococcus pneumoniae, the bacteria that causes pneumonia, is able to evade the immune system.

Its trick is really quite simple. It has a gene for an enzyme that catalyzes the formation of a gooey capsule. Inside the capsule, the bacterium is protected.

Griffith worked with mice, animals which are extremely susceptible to the Streptococcus bacteria. The basic experimental technique was to inject an unfortunate mouse with bacteria. Within a day, it would be dead.

But Griffith had found a few naturally mutated Streptococci that lacked the protective capsule. Evidently they had lost the function of the relevant gene. He was able to reproduce those bacteria in great numbers and when mice were injected with the capsuleless strain, they did the mice no harm.

If the infectious type of bacteria were killed by high temperature and injected into mice, the mice were also unaffected.

But when Griffith injected mice with both the killed infectious Streptococci and the live capsuleless strain, the mice were killed, and furthermore, living infectious Streptococci were found in the dead mouse's blood.

Somehow a dead bacterium was able to pass a gene to a living bacterium. This didn't have to happen in a mouse. If the dead infectious bacteria were whipped up in a blender the resulting mixture of protoplasm was enough to transform a few of the capsuleless bacteria into the infectious type.

Griffith had no idea what he was doing. In 1928, nobody even suspected that DNA was the genetic material. But he was the first person to transfer a gene from one organism to another. (Of course, the bacteria had been doing it for eons with no help from us. In fact, bacteria can get DNA from unrelated species of bacteria.)

Griffith was killed during the bombing of London in 1941. Three years later Oswald T. Avery was able to show that the material necessary to transfer a gene was DNA. Many bacteria have a single chromosome containing most of their genes, but they may also have a very small chromosome called a plasmid, holding only a few genes. Bacteria can pass these tiny plasmids through their cell walls into the outside world, where other bacteria can take them in and use them to build working enzymes.

[23] Troubles for Greenpeace

Greenpeace was founded by idealists who wanted to protect the environment. They showed, and still show, a real flair for getting publicity. They understood that the media can't resist covering their unexpected and sometimes outrageous stunts. These have included driving rubber rafts around whaling boats, and dumping pollution in front of the corporate headquarters of polluting corporations.

Often these stunts involve activity that is illegal, but the actual violations have usually been minor and have typically been excused by their interpretation as symbolic speech. Eventually, however, Greenpeace leadership may have decided that they were above the law, or at least that they were justified in breaking laws by the virtue of their causes. From there it has been only a small step to conclude that other means are justified by the ends.

Greenpeace's success attracted lots of support and lots of money and Greenpeace is, today, a large multinational business with an annual budget in excess of $100 million.

With size, Greenpeace has taken on the characteristics of a big business, including a charge that it exploits its labor force. More important, its very success, with almost everyone now claiming to be concerned about the environment, has forced it to look further afield for causes to champion. This report tries to make clear that, at least in the case of its campaign against genetically modified food, Greenpeace has moved so far from its original mission that it is actually on the anti-environmental side of an issue.

Patrick Moore was one of the twelve founders of Greenpeace in 1971. He was a director for fifteen years and was the president of Greenpeace Canada for nine years. But he was able to see the drift of the organization toward positions that were harmful to the environment. He thought that it was time to switch from negative confrontational action to positive constructive dialog. After years of trying to influence their direction from the inside, he formed his own environmental organization, Greenspirit ( http://www.greenspirit.com ), with the same environmental goals as Greenpeace once had. In 2000 he publicly broke with Greenpeace over the genetics issue.

[24] Lectins

Lectins are poisonous compounds found in many plants and in their seeds, especially beans, although it isn't clear how this benefits the seeds. Our bodies' natural detoxification system can cope with small amounts of most lectins, a few parts per thousand. In higher amounts, lectins cause blood clotting and they interfere with the immune system.

One kind or lectin, called ricin, is extremely poisonous. It is found in castor beans. Ricin became briefly notorious in 1978 when a Bulgarian journalist in London was assassinated with the poisoned tip of an umbrella.

Consume foods with lectins and the first part of your body to be affected is the wall of the gut, which can become inflamed. Lectins absorbed into the bloodstream can also cause cancer.

Fortunately, lectins are water soluble and are destroyed by high temperature. So, although you should avoid eating raw beans, cooked beans are fine.

[25] Starlink Corn

At least one variety of transgenic food, Starlink corn, has not been approved for human consumption. This is not because it has been shown to be dangerous, but only because it has not yet been shown to be safe.

The transgenic protein in Starlink corn, Cry9C, is meant to kill certain insects. It is one of the natural Bt toxins. For humans, it should be a nutrient like almost any other protein. But while most proteins are digested in the stomach within seconds or minutes, Cry9C is digested more slowly.

Neither laboratory animals nor human subjects have shown allergic sensitivity to Cry9C and its amino acid sequence is not similar to any other known allergen. However, because Cry9C is digested slowly, it is difficult to prove that it wouldn't be an allergen for somebody. So although it has not been shown to cause harm, the FDA refuses to allow it to be used except as animal feed. (Experiments with farm animals have shown that Cry9C is digested quickly in their alkaline stomachs.) Testing for safety to humans continues.

Someone should ask Dr. Billings how it can be that a food which is not required to be tested for safety is not allowed to be used for human food.

[26] Scorpion Genes

People eat fish and people eat tomatoes. Often they eat them together. After all, tomato is an ingredient in many of the best fish recipes, like bouillabaisse. So at least some people are not bothered by a fish gene in a tomato.

For these people the critics talk about a more scary example. They claim that genetic engineers have transferred a gene for a scorpion toxin into corn. They ask, ``Do you want a scorpion gene in your cornflakes?''

Although genetic engineers have used the gene for scorpion toxin, they didn't transfer it into a plant. Instead it has been used to genetically engineer a virus that parasitizes a plant pest, the cabbage looper. If it works, farmers could protect existing plant varieties from cabbage loopers without use of chemicals. The technology is presently undergoing field trials in England.

As nearly as I have been able to determine, the story about corn with a scorpion gene is a complete fabrication, but it has been widely spread. It seems to have originated with the Natural Law Party, one of the many organizations that campaign against genetic engineering.

[27] Bioluminescence

Asked to name a living thing that makes light, most people will think of a firefly and a few others will mention a glowworm. Both are insects, but they are not the same. A glowworm is the larvae of a certain kind of fly. They live in caves and obtain food by dangling sticky threads from the roof of the cave. Other insects are attracted to the threads by the glow. So the glow is a lure to attract their food.

Fireflies are predatory beetles that glow to attract mates. Each species of firefly has its own flash timing pattern. But the female of one firefly species mimics the flashing pattern of another species. When the tricked male firefly comes expecting to find a mate it becomes dinner.

There are no known plants that glow, but there are bioluminescent mushrooms. One of the most beautiful is an orange mushroom (Clitocybe illudens) that glows and has earned the name Jack O'Lantern.

A fungus is also responsible for another curious case of living light. Sometimes at night, in the woods, the forest floor seems to glow. Close examination will reveal glowing twigs. They're called foxfire.

Most of the world's glowing happens in the sea. About half of all kinds of jellyfish are bioluminescent. In the deepest part of the oceans, where there is never any sunlight, as many as eighty percent of the fish, squid, starfish, etc. produce light. A particularly ugly fish, the angler, dangles a little bait ball in front of its huge mouth. The ball is filled with glowing bacteria. Any fish who comes to investigate is swallowed whole.

Some kinds of deep sea squid squirt glowing ink when they are attacked. In the black depths of the ocean, the glowing cloud blinds and confuses predators and lets the squid escape.

If you live near a beach, on dark lights you can find nearly microscopic creatures flashing tiny sparks in the surf. These are probably dinoflagellates, tiny marine algae. It was Benjamin Franklin who first suggested, in 1753, that the sparks in the water might be produced by creatures too small to see with the naked eye. Sailors often see the ocean water glowing in the disturbed wake of a ship.

Perhaps the most curious glowing creature is the railroad worm. It's a beetle larva with rows of alternating red and green lights along its sides. Perhaps someday scientists can transfer its genes into a tree, and it can become a traffic light.

The chemistry and the genetics of living light are well understood. The enzyme luciferinase causes the oxidation of a substance called luciferin, which is the energy source for the light. The reaction can be duplicated in the laboratory, or even in toys.

The genes have been transferred to be used in transgenic plants as markers that prove that another gene transfer worked. They've also been transferred into bacteria that then do medical diagnoses. In fact, the genes for bioluminescence might hold the record for being transferred into the largest number of other species.

[28] Suicides in India

Suicides by Indian farmers because of crop failures are a real and recurring tragedy. Other unfortunate farmers have had to sell their kidneys or other organs to raise cash. Since India has yet to allow any transgenic crops to be grown, except experimentally by researchers, there is no way to attribute these suicides to genetic engineering. One would expect that pest resistant crops would be less likely to fail, and therefore suicides would become less common.

[29] Biopiracy in Reverse

In 1996, the Monsanto Company teamed up with Maharashtra Hybrid Seed Company (Mahyco) to introduce Bt cotton to India. The Indian government required the companies to carry out a series of tests to prove that their cotton variety would grow well in India and that it was safe for the environment. These tests were begun and completed and none of the tests revealed any problems. But each year thereafter the government asked for more tests. Bt cotton has been grown safely in the United States since 1996, and is grown in China and South Africa. India finally approved transgenic cotton On March 26, 2002.

Around 1998, an employee of Mahyco resigned and formed his own company, Navbharat Seeds Limited. Navbharat began to sell ``hybrid'' cotton seeds claimed to resist the bollworm. India doesn't regulate hybrid seeds at all, and for three years nobody thought to question their hybrid character. But in the fall of 2001 cotton farmers in the state of Gujarat lost almost their entire crop to bollworms, except for the farmers who had planted Navbharat's seeds. Suspicious, Mahyco tested some of the Navbharat cotton and proved that the plants contained the gene for the Bt toxin, which was protected by a Monsanto patent. Mahyco had been patiently complying with with the government's required tests for five years while their competitor was selling similar seeds without any regulation. At least 10,000 acres of Gujarat were planted in Bt cotton.

The Indian national government ordered that the transgenic cotton be burned in the fields, and that the Gujarat state government compensate farmers who had bought the illegal seeds. But it was too late. Much of the cotton had been harvested, and Gujarat's state government didn't have enough money to compensate the farmers.

Meanwhile, Mahyco was asked to perform still more tests.

India should have been the last place in the world to resist the introduction of pest resistant cotton. The very large Indian textile industry uses a great deal of imported cotton. Local cotton farms cannot produce enough supply. Too much of the Indian cotton crop is lost to insect pests. About half the pesticides used in India are applied to their cotton crop. In 1984 the world's worst ever industrial accident, at a pesticide factory in Bhopal, India, killed about ten thousand people and sickened thousands more. What conceivable harm could Bt cotton cause in comparison to such a disaster?

[30] Patents on Life

It is legal, in most but not all countries, to patent a life form. More recently it has become legal to patent a gene.

This makes many people philosophically uncomfortable. The usual justification of patent rights, that they encourage and reward research, clearly applies to research about living things as well as to research about machines and chemicals. On the other hand, most people feel that life is in a different category and that there is something not quite right about owning a life form in the same way that one can own a non-living thing. Perhaps we can imagine being owned ourselves, and we don't like the idea.

The principle of patents on life sort of snuck up on us, through the business needs of plant breeders.

There are several different methods of plant reproduction. Let's start with the simplest method, cloning. Cloning for some species is hardly high technology. You can cut up a potato and grow a new potato plant from each of the pieces. A strawberry plant will produce runners and completely new strawberry plants can sprout up wherever the runners take root. The new plants are identical to their parents in every gene.

By contrast, one can grow potato plants or strawberry plants from seeds, which are all genetically different from one another.

To protect breeders' rights, it seemed reasonable to allow a breeder to patent a particular variety of strawberry or potato, where all plants of that variety were identical and were developed by that breeder as a consequence of judicious crossbreeding. But patenting was not available for seeds because it was impossible to guarantee the exact genetic components of seeds.

However, by inbreeding over enough generations, it is possible to make living things that are very close to genetically identical. Most plants have two copies of each gene and they pass one or the other, but not both, to offspring, who get the other gene from the other parent. Therefore if both parents each have two identical copies of a gene, four identical copies in all, that trait should ``breed true'' in future generations. The more different kinds of genes that are identical in this way, the more nearly alike the progeny will be. It seemed logical to extend the idea of patent protection to such ``pure lines'' but it didn't matter much in practice since the pure lines were seldom of any economic importance.

That changed when the idea of hybrid seed was conceived. Often a plant with two different genes is better, in some way, than one with two identical genes. By crossing two pure lines, one obtains seeds all identical to one another but different from their parents and, by design, better. But this hybrid seed will not breed true. So the patenting of pure lines and of the cross between two particular pure lines became appropriate.

Things got more complicated when it became possible to keep individual cell lines dividing indefinitely. Surely these cells were all identical and by analogy with pure lines or cloned varieties, they were patentable. But the twist here was that they might be human cells, and therefore there might be two humans with a claim to their ownership, the scientist who isolated them and the donor. Court cases settled the issue in favor of the scientist.

Patent law was shaken up again when it became possible to isolate particular genes and protein sequences. The gene sequences are like sentences in a book. You can't, of course, patent a book if you didn't write it -- we normally talk about copyright, rather than patent, when we're protecting artistic creativity -- but a genome is not really a book and the patent law, at least in some countries, allows ownership of a gene if it can be isolated and if its function is described. This was more like patenting a sentence, not a whole book, if you could write out the sentence and explain its meaning.

Here was the owner vs donor issue once again.

It gets worse. There are researchers in developed countries who investigate plants and animals in undeveloped countries. Inevitably they discover useful traits. In many cases, they have patented the genes of third world plants. Since patents in one country may be valid in other countries, the residents of underdeveloped countries may find themselves forced to pay licensing fees to use their own heritage. This has mostly been an imagined problem so far, but it has drawn complaints from third world activists, who refer to such patenting as biopiracy.

[31] How ``Terminator'' would Work

A and B are already present in the plant. Gene A specifies production of a protein which is used to finish building a seed. Gene B is a switch gene which can turn on gene A. Gene A is turned off in most of the plant most of the time. It is turned on, by gene B, only in the developing seed and only at the end of development.

The other five genes are to be put into the plant. Gene C specifies a protein that will kill the seed. Gene D is another exact copy of gene B, the switch gene, but controlling gene C instead of gene A. It therefore turns on gene C only in the developing seed and only at the end of its development.

Together, genes C and D would achieve the desired function of causing the plant to have only sterile seeds. But this would give the seed company a problem. How can the company reproduce the seed to have a supply to sell?

The other three genes solve that problem. Gene E is another control gene, whose function is to interfere with gene D. As long as gene E is present, gene D cannot turn on gene C and the plant will make fertile seeds.

Gene F specifies a protein which is able to snip gene E out of the plant's DNA. Once gene E is gone it is gone forever and the plant will make infertile seeds. Finally, gene G is a control gene which will only turn on gene F when the completed and fertile seed is exposed to teracycline.

To recapitulate, the seed company would reproduce the plant in the usual way. Gene E would have turned off gene D which is needed to turn on gene C and make the seed sterile. When the seed company was ready to sell seeds to a farmer, they would soak the seeds in tetracycline which would stimulate gene G to turn on gene F, which would cause gene E to be snipped out of the DNA. With gene E gone, when the plant grown from the treated seed makes seeds of its own, gene D would cause gene C to make the protein that kills the new seeds just as they complete their development.

This whole system is much more complicated than anything accomplished by genetic engineers in the present generation of transgenic plants. These have, at most, one control gene and one protein making gene.

[32] Why Genetic Engineering Lets Farmers Save More Kinds of Seed

Farmers who use hybrid seed must buy new seed every year because the benefit of hybridization does not pass to the next generation. Here's why:

Sexually reproducing animals and plants have two copies of each chromosome. The two genes at corresponding sites on these two chromosomes may be alike or may be different. Sometimes there is an advantage to having the two genes different. If one parent plant has two type A genes and the other parent plant has two type B genes, the next generation's crop will each have the desired AB combination. But if the seeds from the hybrid crop are saved, in the second generation some plants will be AA, some will be BB and only about half the plants will have the desired combination AB.

When two or more different gene sites are involved, first generation hybrids will all have the desired gene distribution, but almost all of the second generation will be missing at least one desired gene.

But genetic engineering makes it possible to create a pure strain of plant which has two copies of each of the desired genes, so that it will have the desired hybrid traits but will breed true. These plants would not be strictly transgenic but they would certainly be genetically modified.

Seed companies might protect their investment in developing such seeds, just as they now protect their rights to plants which reproduce asexually, by patenting, by requiring farmers to sign contracts, etc. This is not a scientific criticism, but a legal one. Patents only run for twenty years. In principle, genetic engineering ought to give more poor third world farmers a chance to save seeds from year to year, exactly the opposite of what the critics have feared.

[33] Grafting and Budding

Many woody plants are reproduced by one of two closely related tricks, grafting and budding. Grafting was practiced thousands of years ago in China.

In grafting, a twig from one tree or bush is made to grow on the root of another closely related plant. This trick is often used to combine the vigorous root system of one plant with the pleasing shape or good fruiting characteristics of another.

Suppose we have a wild apple tree, a few years old, with a healthy root system and a firm straight trunk, perhaps an inch in diameter. Call this the rootstock. Suppose we also have another apple tree which can bear luscious fruit. Call that the scion.

Here's how we combine the two. We cut a branch or twig from the scion and make the cut diagonally. Then in the rootstock we make a shallow cut in the trunk, not all the way through. This makes a flap. We put the diagonally cut branch of the scion against the rootstock's trunk, under the flap, and we use tape or string to bind the two together. Then we wait.

Months later, the cambium layers of the rootstock and of the scion will have grown together and the fruit tree branch is now a branch of the wild apple. At this point, we can cut off the top of the rootstock, removing all the growth above the graft. The grafted branch is now the new trunk, with an obtuse angle at the point of the graft. After a few years, the trunk will straighten itself out, and the former branch will, itself, produce branches.

This procedure produces a tree whose trunk and branches have the genetics of the scion and whose root system has the genetics of the rootstock. This is a great way to get one tree with both the best possible root characteristics and the best possible fruit characteristics. If the fruit tree had dozens of branches, each one could be grafted onto a different rootstock so that we get many good fruit trees from one. Later, twigs from the resulting plant can be used for further grafts, so that one original tree can give rise to hundreds or thousands of identical clones.

Lots of different woody trees and shrubs can be reproduced in this way. Most fruit trees and decorative trees you buy from a nursery are grafted. How else could the nursery be sure you were getting a young tree with the characteristics you were promised?

You can't expect grafting to work if the rootstock and the scion are not closely related. But there is a trick that can bridge a relational gap that's just a little too wide. We first graft an intermediate scion to the rootstock. When that graft has worked, we can graft a second scion onto the resulting tree. If the rootstock is compatible with the intermediate scion and if the intermediate scion is compatible with the final scion, this trick gives us, by a two-stage graft, a marriage between a rootstock and a scion that are not mutually compatible.

Instead of transplanting a twig, one can transplant a bud. In fact, one can transplant several buds at the same time. Have you ever seen, in a nursery catalog, an advertisement for a tree that bears several different kinds of fruit. Now you know how the tree was produced.

Grafting and budding are not trivial. With luck, an amateur may be successful but it takes substantial training and practice to get the techniques to work reliably. They almost never happen by by themselves in nature.

[34] Rice Nutrition and Consumer Preferences

The first vitamin to be discovered was thiamin, also called vitamin B1. In 1897, Dr. Christiaan Eijkmann was working on the Indonesian island of Java. There some of the natives were suffering from a debilitating disease called beri beri. Symptoms were muscle weakness, weight loss, nervous disorders and ultimately paralysis and death. Dr. Eijkmann was searching for an understanding of the cause of beri beri and a lucky accident gave him a clue. He noticed some chickens exhibiting some of the same symptoms as the beri beri victims.

The chickens were fed rice. The outer surface of a grain of rice is a light brown layer called rice bran. Left on the rice, it is called brown rice. But people in Asia prefer to eat white rice, rice for which the outer surface has been polished away. White rice was more expensive than brown rice, so the chickens were usually fed brown rice. But the sick chickens had been fed white rice, and little else. The conclusion was that there might be an ingredient in rice bran which prevented beri beri. This turned out to be the case. Eventually the B vitamins were isolated in pure form.

We've now known for more than a hundred years that brown rice is more nutritious than white rice. But most Asian cultures associate eating white rice with prosperity and eating brown rice with bad luck. Most rice is still milled, both in Asia and elsewhere. In Europe and America both white rice and brown rice are consumed, but mostly white. In fact, some white rice is chemically fortified to add back the B vitamins.

Even Mao Zedong was not able to change the eating traditions of Chinese peasants. It is therefore certainly possible that traditional people will reject golden rice because of its yellow color.

On the other hand, in much of India and nearby countries, rice is often cooked with spices, like turmeric, which make it yellow. In such cultures yellow rice might even be preferred over white rice.

[35] Unstable DNA

There are parts of a DNA string that are very susceptible to change. Most of these involve places where the sequences repeat. For example, there is a part of the human genome on chromosome four where the sequence CAG is repeated six or more times. The other strand of DNA in this gene has repeats of GTC. This sequence happens to lie within a gene, called huntingtin.

The two strands of DNA normally bind together because A attracts T and G attracts C. Therefore it is possible for DNA strands with short periodic sequences to bond incorrectly with one strand shifted by three letters from the other. This, of course, leaves a short length of DNA at each end of the repeat segment where the DNA strands cannot bond. But there are repair enzymes which go to work on such mismatched DNA and one possible repair is to splice in an extra CAG on one end of the repeat segment and an extra GTC on the other end. So the repaired DNA molecule would have seven CAG repeats instead of six, and when the cell divides this change is copied.

But the longer the repeat of CAG, the greater is the probability of this mistake happening again, producing a still longer repeat sequence.

When this process runs out of control, the gene may have a very large number of repeats and the protein synthesized using that gene becomes less and less functional. Eventually the person whose DNA has many extra repeats of CAG gets a disease called Huntington's chorea, characterized by a relentless wasting away.

An individual born with extra CAGs in the huntingtin gene is likely to develop Huntington's chorea. The more extra CAGs there are in the gene, the earlier in life the disease will show up.

There are several other human genetic diseases that are also caused by the same kind of repeating sequences in a gene.

[36] Norman Borlaug and the Green Revolution

Dr. Norman Borlaug was born and raised on an Iowa farm and studied plant pathology at the University of Minnesota in the nineteen thirties.

In 1944 he was asked by the Rockefeller Foundation to work in Mexico on a project to improve productivity of wheat. He and his staff worked for twenty years to develop a dwarf variety of wheat that put less of its energy into growing tall and more of its energy into growing fat kernels, while resisting several different plant pests. In 1965 he moved his attention to India and Pakistan, where he began a massive education campaign to get the new varieties to farmers, while continuing to further improve them.

The results were dramatic indeed. Since 1970, the total yields of wheat in these two countries have increased by nearly ten times. This is why, despite the doubling of their populations, the populations of India and Pakistan are better fed today than at any time since 1965.

The International Rice Research Institute modelled its methods on Borlaug's work with wheat, and later with corn, and has had similar outstanding success.

Many of the same groups who oppose genetic engineering are critical of the green revolution. They complain that the crops developed rely on fertilizers, which make the third world farmer dependent on resources he must buy. Those critics who believe exclusively in organic farming say that fertilization is unsustainable.

They also complain that the genetic diversity of hundreds of individual varieties is wiped out when everyone grows the single ``best'' variety. They say that a new insect or fungus that can attack that single variety would destroy the crops of a whole country.

Dr. Borlaug considers these critics to be poorly informed. He calculates that there is just no way the world's present population could have been fed with the agricultural techniques of the 1960s.

He says ``Extreme environmental elitists seem to be doing everything they can to stop scientific progress. Small, well financed, vociferous, anti-science groups are threatening the development and application of new technology, whether it is developed from biotechnology or more conventional methods of biological science.''

[37] Cassava Culture

The cassava plant is the world's third most important crop. Although it originated in Brazil (where it is called manioc), it was brought to Africa by Portuguese colonists, and it is now an important crop there and in Indonesia and Southeast Asia. It is the principal source of nutrition for about 500 million people. Its leaves are edible but the prize is its starchy root, rich in protein, minerals and vitamins A, B and C.

Cassava enters the North American diet also - we make it into tapioca.

Surprising for an important edible plant, it is quite poisonous without proper preparation. The toxin in cassava is called linamarin. It is chemically similar to sugar but with a CN ion attached. When eaten raw, the human digestive system will convert this to cyanide poison. Even two cassava roots contain a fatal dose of poison.

To prepare cassava, it is peeled and grated and soaked in warm water for several days. This allows the cassava's own natural enzymes to convert the linamarin to sugar and cyanide gas, and the gas disperses harmlessly. What remains can be boiled and eaten, or more usually, dried and ground into flour.

Improperly prepared cassava was the cause of a mysterious disease called konzo, first discovered in Africa in the 1930s. It is really chronic low-level cyanide poisoning.

[38] The Cold Sore Virus

Have you ever has a cold sore? It's a swollen sore, usually on your lips or in your mouth.

If you answered ``no'', the chances are pretty good that you never will in the rest of your life. But if you have had cold sores, you will almost certainly have other episodes from time to time.

A cold sore is caused by a virus, called herpes simplex. When you are infected by a herpes virus, it first begins the usual virus life cycle. The virus DNA directs the cell's own machinery to make more copies of the virus and then the cell bursts to let the new viruses repeat the process.

But after a number of these cycles, the virus changes its strategy. It gets into a target cell, as before, but instead of reproducing, it causes its own DNA to be stitched into the cell's native DNA. As far as the cell can tell, it has a few more genes than it had before, but they are turned off so they don't do anything. The cell goes through its normal life and, eventually, reproduces. The act of reproduction includes making a copy of its DNA, including the genes of the virus. Where there had been one virus DNA string, there are now two.

After many such cycles, something may trigger the dormant virus genes in the cell's DNA to become active. When that happens, they direct the cell to make lots of copies of the virus and then burst open. It is when viruses are reproducing in that way, and killing cells, that you get the cold sores.

This virus life history is the reason that people who get cold sores get them recurrently. The dormant virus is the perfect parasite, doing no harm whatever to its host, except for an occasional bout of sores. Cold sore virus, once inserted in a cell's DNA, is there for good.

A similar virus is responsible for genital sores, and is sexually transmitted, but only during the phase when the virus is active. Some drugs can persuade the virus that ``Now is not the time'' but this is also an incurable condition.

Th ultimate virus parasite is one that, once incorporated into the DNA, becomes perpetually dormant. If that sort of virus infects a sex cell, its DNA becomes a permanent part of the genome of the species.

[39] Diptheria's Toxin

Viruses can insert their DNA into another organism's chromosome and become part of that other organism's genome and furthermore, the viruses can carry genes into the other organism's chromosome which code for new traits.

Surely the example of this that has been responsible for the most human misery has to do with diptheria.

The pathogenic bacteria that causes diptheria is Corynebacterium diptheriae. But although this bacterium is capable of infecting humans, it is not deadly. However C. diptheriae can, itself, be infected by a virus. The virus can either kill the bacterium to reproduce itself, or it can insert its DNA into the bacterial chromosome.

It is one of the viral genes, when inserted into the bacterium's DNA, that gives the bacterium the ability to produce a protein toxin, the deadly diptheria toxin. So, in effect, humans can become the victims of C. diptheriae only when it has become the victim of the virus.

[40] Atrazine vs. Glyphosate

The herbicide most commonly used in cornfields is atrazine. It kills most weeds, but it does not harm corn plants. Corn has now been genetically engineered to tolerate glyphosate, which can therefore replace atrazine as a weed control in cornfields.

The EPA considers water unsafe to drink if it has three parts per billion of atrazine, but the comparable limit for glyphosate is 700 parts per billion. By this measure, glyphosate is 230 times less toxic than atrazine.

[41] Label Costs

[42] Long Term Consequences of Labelling Transgenic Food

Paradoxically, once all food which may contain GMOs must be labelled, manufacturers would put such a label on most food without worrying whether it does or does not actually contain GMOs. Their customers are not, after all, objecting to non-GMO food. But the venders who sell food without the label will have to go to considerable expense to prove the absence of GMO content. Farmers will have to buy certified non-GMO seed and ship their crops in certified trucks and to certified storage bins, etc. Non-GMO processors will have to prove that they are not using GMO ingredients whereas the majority of processors won't have to bother. Remember that the cost of labelling is not the cost of the label, but the segregation and certification that gives the label its meaning.

On April 5, 2001, the Wall Street Journal reported on a survey of food labelled GMO-free . Their reporters collected about two dozen processed foods such as vegetarian meat substitutes, or corn flakes, all labelled as free of genetically modified content. These were sent to a laboratory for testing. Every developer of a genetically modified food has published the sequences of the transferred genes, so it is relatively straightforward for a laboratory to look for these sequences.

Almost all the foods labelled GMO-free were found to contain significant amounts of transgenic content, in one case about 40%. Journal reporters contacted the manufacturers for explanations. Generally they had either tested their supplies, or paid a premium to farmers or millers to supply a segregated product. The fact that this didn't work surely shows that even greater and more expensive efforts would be needed to keep transgenic and non-transgenic products separate.

[43] Extreme de L'extreme

The most extreme opponents claim that growing transgenic crops pollutes the land, and they would not allow any crops to be grown later on the same land. A large fraction of American farmland would be retired if they were to prevail.

[44] Misleading with Binomial Nomenclature

Normally biologists insist on using the Linnean binomial names, (e.g. Oriza sativa), even when common names (rice) would be perfectly clear.

[45] About Monarch Butterflies

Monarch butterflies (Danaus plexippus) are remarkable insects.

After a feast of nectar, the monarchs lay their eggs on milkweed plants. The larvae hatch and become white caterpillars with colored stripes. They eat nothing but milkweed all summer long, growing big and fat. Each caterpillar then attaches itself to the bottom of a milkweed leaf and turns itself into an iridescent blue cocoon. Within the cocoon, the caterpillar literally dissolves away and regrows as a butterfly.

When it hatches from the cocoon, its wings are wet and crumpled up and it's a piteous thing to behold. But in a few minutes, it manages to inflate its wings and dry them in the warm fall sunshine and soon it can fly away.

Many brightly colored butterflies have a taste that birds don't like. The monarch, black and orange, fits this pattern. Their bad taste comes from the milkweed plant that they consumed as caterpillars. The colors are a warning to birds - ``You won't like me.'' But there are other species of butterfly, quite unrelated to the monarch, that turn this to their advantage by imitating the color and pattern of the monarchs. Birds usually avoid these species as well, although they would taste just fine (to a bird).

The monarch may be the only insect that makes a seasonal migration. Each fall, monarch butterflies living east of the Rocky Mountains fly by the millions to a winter habitat in the Mexican state of Michoacan. The delicate and seemingly fragile insect flies up to two thousand miles to reach Michoacan and reverses the journey in the spring.

All these millions of butterflies congregate at only a few tiny sites in Michoacan. Trees there are covered with tens of thousands of butterflies, a sight that attracts tourists to these remote destinations.

Although monarch butterflies are not an endangered species, they are vulnerable to a possible loss of this restricted winter habitat. Until recently Mexican loggers had been cutting trees from on the butterfly refuges, but the Mexican government has now designated most of these refuges as protected sites. In January of 2001, a snap of cold weather in Michoacan killed millions of monarchs at one site.

As befits such a beloved insect, there are monarch ``fan clubs''. One, called the monarch project, has been collecting and tagging monarchs for years. Beginning in 1966, the number they have been able to collect has increased each year, approximately tripling by 2000. This roughly corresponds to the adoption of Bt corn in the midwest, although it might also be due to weather or other factors.

[46] Fifty Percent More Land

This is an exaggeration based on a worst case. In some fields, in some seasons, there are very few borers. In the US, since the introduction of Bt corn, yield improvements attributed to borer control have averaged 7%. But in general, even without genetic engineering, organic agriculture typically has lower yields per acre than conventional agriculture.

This must not be understood as a criticism of organic farming. All farmers are motivated to increase their yields and today's organic farmers have learned to get higher yields than were achieved by previous generations. There is no reason to think that future techniques for organic farming won't achieve still higher yields.

[46] Horseshoe Crabs

The first time you see a horseshoe crab, you will probably be reminded of Darth Vader's helmet, or perhaps some medieval precursor of a battle tank. The animal has some working parts like claws and legs down below, but all you see from above is a rounded shell, a spiky tail, and if you look closely, two different pairs of eyes. Even though horseshoe crabs look threatening, they are quite harmless.

This body design has served the horseshoe crab for about five hundred million years. They were contemporaries of the trilobites. The modern species is essentially unchanged from fossils recovered from the rocks of the Triassic period, when dinosaurs were the dominant land animals. Despite their common name, horseshoe crabs are not closely related to crabs.

Like crabs and lobsters, a horseshoe crab can only grow larger by molting. It literally crawls out of its shell, grows a little bit before its new shell gets hard, and repeats the process over a dozen times in the first few years of its life, but only about once a year after it is mature. Most of the Limulus shells you find along the Atlantic beaches are molts.

Limulus is what ecologists call a keystone species. Many other species rely on it heavily. This is especially true of the species who eat its eggs.

The horseshoe crab mates and spawns at the shoreline, relying on the highest tides at full and new moons in May and June. The females produce thousands of translucent green eggs. There are several migrating birds that rely on the eggs for food. For example, red knots (Calidris canutus) spend our winters in Tierra Del Fuego and fly to the Arctic regions in our spring. They migrate farther than any bird, flying non-stop until they reach the Delaware Bay, where, having timed their arrival perfectly, they gorge themselves on horseshoe crab eggs before embarking on the last leg of their journey north.

The mature horseshoe crabs are the most important food source for loggerhead turtles, and many other species eat the larvae. They are also economically important. They are used as bait in traps set to catch eels and conches. In the last century until about 1920, they were even used as fertilizer.

But it is the medical use of horseshoe crabs that is most intriguing. Fishermen capture the crabs and bring them live to certain laboratories, where they are bled. The blood is the source of a substance called Limulus Amebocyte Lysate which can be used to detect an otherwise elusive kind of bacteria, and to sterilize medical instruments. About a third of the available blood is collected and then the donor is released - most of them survive the experience. The blood is blue. Its oxygen carrying protein is based on copper instead of iron.

These primitive creatures were also used as the experimental animal in some of the first studies of how nerves worked. Nerve cells can be very long but microscopically thin. But the nerves that carry impulses from the eye of the horseshoe crab to its brain are fairly large and can be manipulated without microscopic aid. H. K. Hartline began studying the crabs vision system in the 1920's and eventually received a Nobel prize for his contributions to the understanding of vision.

[48] Treating Cancer with Viruses

Cancer is not one disease, but many. It is intimately linked with the function of certain genes. Cancers are caused when cells' natural control of their own reproduction goes awry and they reproduce uncontrollably. But our cells have several fail-safe systems that cause cells to commit suicide when their normal controls go wrong. The cancers that go beyond the single cell stage are those for which these mechanisms no longer work.

One of those fail-safe mechanisms is controlled by a gene called P-53. It is defective in about 2/3 of all human cancers. We almost all start life with two good copies of P-53, but if one of them is damaged in some cell, that cell's descendants are susceptible to losing the other P-53 in a single mutation event. Even so, the cell can continue to function until some other disaster befalls its control of reproduction. That's why some kinds of cancers appear to occur at random.

Therefore, some approaches to curing cancer depend on finding cells with defective P-53 genes and either repairing the gene, replacing the gene, or simply killing the cell.

A very promising therapy is being investigated by a small startup pharmaceutical company, Onyx Pharmaceuticals, founded by Dr. Frank McCormick. He genetically engineered a virus related to the common cold virus, so that it could only reproduce itself in cells with defective P-53. This virus can selectively destroy cancer cells if it can evade the body's immune response.

The beauty of McCormick's virus approach is that cancer cells tend to be near one another. Therefore if a modified virus gets into one cancer cell and reproduces itself, while killing the cell, hundreds of additional viruses emerge in the very neighborhood where they are needed.

Onyx has combined this idea with another. The modified virus is further modified with genes that make it into a factory for producing some traditional chemotherapeutic substance. So when the virus reproduces itself a dose of chemotherapy is administered in the precise place it is needed, along with other viruses.

Chemotherapy almost always has dose related side effects. A dose which would be 100% effective at killing cancer usually has such severe side effects that it cannot be used. The prescribed dose is always a compromise between efficacy and toleration. But the Onyx ``armed viruses'' can deliver a concentrated dose to the cancer cells which, by the time it diffuses throughout the body, becomes a negligibly small dose.

Onyx' first virus therapy, called O-015, has already cured some ``uncurable'' cancers and is now in phase III (advanced) testing. The ``armed viruses'' are still being developed.

Meanwhile, other investigators have modified a polio virus so that it selectively reproduces in brain tumors, which have a different defective gene.

The End

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