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Sick Bees – Part 18E: Colony Collapse Revisited – Genetically Modified Plants

First published in: ABJ December 2012



Genetically Modified Plants

What Is Genetic Modification?

There’s Nothing New About Transgenics

GMOs

An Odd Series of Connections

The Vilifying of Monsanto

What Are They Up To?

Practicality Overrides Principle

Hold the Hate Mail

The Changing Face of Agriculture

Bt Crops

Roundup Ready

Direct Effects of Roundup Use

Indirect Effects of Roundup Use

The Future of Roundup

Reality Check

Looking Ahead: The Chemical Treadmill & Pest Resistance

Additional Discussion

The Back Story on Plant Breeding and GM Crops

The Profit Motive

Enter GM Crops

The Second “Green Revolution”

Cautions About GM

Perspectives on GM

So What’s The Problem?

Acknowledgements

References

 


Randy Oliver
ScientificBeekeeping.com

Genetically modified (or GM) plants have attracted a large amount of media attention in recent years and continue to do so. Despite this, the general public remains largely unaware of what a GM plant actually is or what advantages and disadvantages the technology has to offer, particularly with regard to the range of applications for which they can be used [1].

The above quote is certainly an understatement!  Genetically Modified Organisms (GMO’s) are a highly contentious topic these days, and blamed by some for the demise of bees.  In researching the subject, I found the public discussion to be highly polarized—plant breeders and farmers are largely enthusiastic (with appropriate reservations) about the benefits of genetic engineering, whereas health and environmental advocacy groups tend to be fearful of the new technology [2].  I will largely save my review of the history and pros and cons of GM crops for my website, and focus this article upon how GMO’s relate to honey bee health.

What is genetic modification?

The knowledge of genetics was not applied to plant breeding until the 1920’s; up ‘til then breeders would blindly cross promising cultivars and hope for the best.  With today’s genetic engineering, breeders can now take a gene from one plant (or animal, fungus, or bacterium) and splice it into the DNA of another plant.  If they get it just right, the new gene can confer resistance to frost, drought, pests, salinity, or disease.  Or it could make the crop more nutritious, more flavorful, etc.  Such genetically modified crops are also called “transgenic,” “recombinant,”  “genetically engineered,” or “bioengineered.”

There’s nothing new about transgenics

There is nothing new about transgenic organisms, in fact you (yes you) are one.  Viruses regularly swap genes among unrelated organisms via a process called “horizontal gene transfer” [3].  For example, the gene which is responsible for the formation of the mammalian placenta was not originally a mammal gene—it was inserted into our distant ancestors by a virus.  If a gene introduced by a virus confers a fitness advantage to the recipient, then that gene may eventually be propagated throughout that species’ population.   Until recently, we didn’t even know that this process has occurred throughout the evolution of life, and didn’t know or care whether a crop was “naturally” transgenic!

GMO’s

Both the scientific community and industry have done a terrible job at explaining genetic engineering to a distrustful public.  There are clearly potential issues with genetic engineering, but they are being carefully addressed by independent scientists [4] and regulatory agencies, especially in Europe:

From the first generation of GM crops, two main areas of concern have emerged, namely risk to the environment and risk to human health.… Although it is now commonplace for the press to adopt ‘health campaigns’, the information they publish is often unreliable and unrepresentative of the available scientific evidence [5].

Jeffrey Smith, in his book “Seeds of Deception” [6] details a number of legitimate issues and early missteps in bioengineering, as well as pointing out the substantial political influence firms such as Monsanto have upon researchers, regulators, and legislators. We should be cautious to take their assurances with a grain of salt.  On the other hand, I’ve checked the claims of other anti-GMO crusaders for factual accuracy, and found that many simply don’t hold water.  For example, two headlined studies of late, one on rats fed GE corn and Roundup herbicide, and another on the purported increased use of herbicides due to GE crops simply do not stand up to objective scrutiny [7].   It bothers me that the public is being misled by myths and exaggeration from both sides.

From my point of view, GE holds incredible promise and should be pursued in earnest, yet must also be very carefully monitored and regulated.  In any case, GE crops have been widely adopted in U.S. agriculture (Table 1), and thus are now a part of beekeeping.

Table 1

Table 1. The genetically engineered traits available to farmers have evolved rapidly as technology improves and as such crops become more widely adopted. Table from http://www.census.gov/compendia/statab/2012/tables/12s0834.pdf.


An Odd Series of Connections

In 1972, the dean of biological sciences at my university hired me to set up a “world class insectary” (which I did).  I raised mass quantities of insects for hormone extraction, in the hope that we might develop a new generation of eco-friendly insecticides [8].  Several years later I was shocked when Monsanto–a widely-despised chemical company with a sordid history– then hired him to create “a world-class molecular biology company” (which he apparently did).   In 2002, Monsanto was spun off as an independent agricultural company.

Jump forward to 2010, when I had the good fortune to work with an Israeli startup—Beeologics—and witnessed the efficacy of their eco-friendly dsRNA antiviral product for honey bees.  But to bring the product to market, they needed more backing.  To my utter astonishment, they recently sold themselves to Monsanto! 

The Vilifying of Monsanto

These days one can simply mention the name “Monsanto” in many circles, and immediately hear a kneejerk chorus of hisses and boos.  Sure, it had been easy for me to enjoy the camaraderie of riding the anti-Monsanto bandwagon; but I realized that that I shouldn’t allow that sort of fun to substitute for the responsibility of doing my homework and getting to the actual facts of the matter!  When I did so, I found that some of Monsanto’s actions did indeed deserve opprobrium; but that much of the criticism directed at the current company is undeserved (Monsanto suffers from an ingenerate inability to practice effective PR).  Concurrent with the purchase of Beeologics, Monsanto hired well-respected apiarist (and columnist) Jerry Hayes to head up a new honey bee health division, and appointed some prominent beekeepers (not me) to its advisory board.  It dismays me that some beekeepers then immediately jump to the erroneous conclusion that Jerry has sold his soul to the Devil—nothing could be further from the truth! 

What are they up to?

Some beekeepers imaginatively feared that Monsanto was about to create a GM bee or was up to some other nefarious plot.  But in reality, Monsanto’s vision of its future direction is anything but evil—I suggest that you peruse their website for your own edification [9], [10].  Of course I was curious as to why they had purchased Beeologics, since the market for bee medicine is far too tiny to draw the interest of a giant corporation.  But one needn’t be some sort of psychic in order to figure out a corporation’s plans—all you need do is to read its recent patents, which are a virtual crystal ball for seeing ten years into the future.  So I searched out any patents containing the words “Monsanto” and “RNAi.”

To my great relief, I found that Monsanto was not up to some evil plot—far from it!  I suggest you read two of the patents yourself [11]:

Chemical pesticidal agents are not selective and exert their effects on non-target fauna as well…Some chemical pesticidal agents have been shown to accumulate in food, and to exhibit adverse effects on workers that manufacture and apply such chemical agents. Thus there has been a long felt need for methods for controlling or eradicating… pest infestation on or in plants, i.e., methods which are selective, environmentally inert, non-persistent, biodegradable, and that fit well into pest resistance management schemes. Plant biotechnology provides a means to control pest infestations by providing plants that express one or more pest control agents. Recombinant pest control agents have generally been reported to be proteins selectively toxic to a target pest that are expressed by the cells of a recombinant plant.

What the patents tell us is that Monsanto clearly sees that the public is sick of pesticides.  Genetic RNAi technology would allow plant breeders to develop crop cultivars that control insect pests in the same manner that the plants naturally control viruses.  All that the breeder need do would be to identify a unique target protein in a particular pest, and then splice a gene into the plant to produce a “blocking” dsRNA molecule that would prevent the pest from building that specific protein.  The beauty is that dsRNA molecules are already naturally found in plant tissues, the blocking molecule would be entirely specific for that pest alone, completely nontoxic to humans or other non target species, and be rapidly biodegradable.  It would be a win all around (except for the pest)—crop protection, no toxic pesticides, and a sustainable farming technology (as well as a market for Monsanto’s products, since they would need to continually develop slightly different cultivars in order to avoid pest resistance).  Who’d have guessed that Monsanto would be leading the way toward developing eco-friendly pest control?  Life is full of surprises!

Practicality overrides principle

Some folk make GM crops out to be some sort of abomination of nature, and shun them with religious fervor.  I’m not sure that this is the best course for environmentalists to take, and that perhaps, in the face of an expanding human population and a warming climate, we should leave all the possible plant breeding solutions on the table.  The organic farming community wholeheartedly endorses the biotechnology of “marker assisted selection” [12], yet arbitrarily draws the line at the directed insertion of desirable genes.  This may sound like heresy, but as an environmentalist, I suggest that GE holds great promise for developing more nutritious plants that don’t require pesticides, fertilizer, or irrigation—all of which would be wins for organic farming.

From a biological standpoint, I simply don’t see GM crops as being any more inherently dangerous than conventionally bred crops.  Our domestic plants today are often far from “natural”—you wouldn’t recognize the ancestors of many.  Be aware that even conventionally bred cultivars of several crops (beans, potatoes, celery, etc.) often turn out to be too toxic for humans. 

This is not by any means a fluff piece for Monsanto or agribusiness.  Farming is not what it used to be.  In the U.S., 85% of farm sales are produced by less than 10% of farms, which hold 44% of farm acreage [13].  A mere six companies collectively con­trol around half of the proprietary seed market, and three quarters of the global agrochemical market [14].  I abhor such corporate domination; neither do I see today’s high-input agricultural practices as being either sustainable or ecologically wise.

  That said, human demands upon the Earth’s finite ecosystem are growing.  There are only about 4.5 acres of biologically productive land on the surface of the Earth available for each current human inhabitant.  Depending upon the culture’s lifestyle, we use anywhere from 25 acres (U.S.) to as little as 1 acre (Bangladesh) to feed and clothe each person.  Unfortunately for the bee (and many other species), due to human population growth there are over 200,000 additional human mouths to feed every single day—each requiring the conversion of another couple of acres of natural habitat into farmland! 

It doesn’t take a mathematician to figure out that if we wish to conserve natural ecosystems that we need to get more yield out of existing cropland!  And one of the best ways to do that is to breed crops that are more productive and pest-resistant.  The plant scientists in the corporate labs are making huge strides in developing such cultivars, both by GM and conventional breeding.  If they manage to file a patent [15], so what?—other breeders can easily “steal” the germplasm away from the patented genes, and in any case, the patents expire after 20 years! 

Monsanto has seen the writing on the wall—farmers and consumers are demanding not only more food production, but also more eco-friendly agricultural practices.  Monsanto research is heading in that direction with their conventional breeding programs, the development of “biological” insecticides [16], and the goal of producing pesticide-free dsRNA crops. Add to that that the company could actually bring to market dsRNA medications against bee viruses, nosema, and perhaps varroa.  All would be huge wins for the honey bee and beekeepers!

Hold the hate mail

Full disclosure: so despite my innate aversion to corporate dominance and corporate agriculture, I feel that we beekeepers should work with Monsanto to develop products for the beekeeping industry, as well as bee-friendly cultivars of crop plants, and have thus personally decided to be a cooperator in their initial bee research trial.  Is this some sort of Faustian bargain?  I don’t know, but as a condition of my cooperation, I asked, and Monsanto agreed, to allow me to share the data collected with the beekeeping community—which could be a big win for us, since Monsanto has some of the best analytic labs in the world!  I feel that it is far better to have Monsanto working on the side of beekeepers, rather than perhaps against us.  At this point, I’d like to leave the GM debate behind, and address the facts of the matter as to any relationship between GM crops and CCD. 

The Changing face of agriculture

Genetic engineering has clearly changed the face of agriculture in the U.S. (Fig. 1).

Figure 1

Figure 1. These three crops account for over half of all U.S. acreage planted to principal crops, and all are worked to some extent by bees. Data from http://www.ers.usda.gov/data-products/adoption-of-genetically-engineered-crops-in-the-us.aspx.

As can be seen from the figure above, any bees near corn, soy, or cotton are going to be exposed to pollen and nectar from GM plants, as well as to indirect effects due to the technology.  So could GM crops be the cause of CCD?

Bt Crops

Biological plausibility: the insecticidal Bt toxins in GM corn and cotton pollen could harm adult or larval bees.

Organic farmers have long used the spores of the bacterium Bacillus thuringiensis (Bt) to kill caterpillars.  Bt spores germinate in the caterpillar gut, and the bacterium produces insecticidal crystalline proteins (Cry proteins) that bind to specific receptors on the insect intestinal wall.  Since different insect species have different receptors on their gut cells, different strains of Bt have evolved to specifically kill various caterpillars, beetles, mosquitoes, etc. [17].  The proteins are so species specific that wax moths can be controlled on combs by Bt aizawai, which produces Cry proteins that are toxic to moth larvae, but not to bees.

Molecular biologists tweak these Cry proteins to make them even more species specific, and then insert them into plant DNA, so that the plant then produces the proteins itself, thus making its tissues toxic to the target species.  In order to delay the inevitable evolution of Cry-resistant pests, growers plant a percentage of “refuge” crop not containing the Cry genes. Even so, any particular Cry gene will only be effective for some number of years until resistant pests show up.

People have expressed concern about a poisonous substance being introduced into plant tissues, and to them I highly recommend the paper “Misconceptions about the Causes of Cancer” [18].  The reality is that plant tissues are naturally awash in poisonous substances.  Plants have needed to repel herbivores throughout their evolution, and since plants can’t run, hide, or bite back, they do it chemically.  Many of our most popular fruits, nuts, grains, and vegetables (and especially herbs and spices) contain powerful phytotoxins.  Their wild ancestors required cooking or leaching before the plant was edible to humans.  Plant breeders systematically select for cultivars with lower levels of (the often strongly flavored) toxins.

Plants that are naturally resistant to pests contain more phytotoxins, often produced in response to damage from insects.  For example, the sprouts of wheat, corn, and rye produce potent mutagens (enjoy that cup of wheatgrass juice!) [19].  And some plants naturally contain symbiotic bacteria and fungi in their tissues, which produce non-plant chemicals [20].  There is absolutely nothing biologically novel about insecticidal toxins in plant tissues. 

The toxicity (or lack thereof) of Cry proteins to non-target organisms, especially upon two “charismatic” species—the honey bee and the monarch butterfly—has been well studied [21], [22], [23].  A recent and very well-designed experiment on the effect of GM Bt corn pollen upon the growth and survival of honey bee larvae was recently performed by a team of independently-funded German researchers [24].  They added pollen from four different sources to a standard semi-artificial larval diet.

Results: surprisingly, the larvae fed the pollen from the “stacked” GM corn containing a combination of three different Cry proteins exhibited a higher survival rate (100%), than those fed non-GM corn pollen!  To me, a big plus for this study was that they also included a positive control of pollen from a wild plant said to be harmful to bees—only about 30% of those larvae survived!  This finding confirmed that even some natural pollens are quite toxic, and that we should compare any toxicity trials of pesticides with those of the natural phytotoxins in nature.

Analysis: CCD and colony mortality occur even in the absence of GM Bt crops; feeding GM Bt pollen to adult bees or larvae does not cause observable adverse effects.

Verdict on Bt crops:  The specific Bt cry proteins used in GM crops were intentionally chosen to not cause harm to bees.  There is no evidence to date that they do.   On the other hand, Bt crops require less use of insecticides that are clearly toxic to bees [25].

Roundup Ready

Monsanto’s pitch is that Roundup Ready® (RR) crops allow farmers to practice weed-free “no till” farming, which saves both topsoil and money.  The catch is that farmers must then douse their fields with Monsanto’s flagship product, Roundup (ensuring sales of that herbicide—a great marketing strategy).  Bayer CropScience has followed suit by introducing crops resistant to its Liberty herbicide, which has a different mode of action.  

Herbicide-resistant crops do indeed address several major environmental problems:

  1. No till farming does in fact require less labor and reduces soil compaction.
  2. Farmers get greater production due to less competition from weeds.
  3. No till also reduces the amount of petrochemical fuel involved in tillage.
  4. No till greatly reduces soil erosion, which has long been a major environmental concern.
  5. No till may help to sequester carbon in the soil, and to rebuild soil.

So what’s not to love about Roundup Ready?  There are a few main complaints—(1) the massive spraying of the active ingredient, glyphosate, for which there is questionable evidence that it may be an endocrine disruptor [26], (2) claims of intimidation by Monsanto of farmers who choose not to plant RR seed, and (3) the environmental impact and sustainability of the sort of weed-free monoculture possible with RR crops.

So how do Roundup and RR crops relate to honey bees?

Direct Effects of Roundup Use

Biological plausibility: either the active ingredient (glyphosate), or the adjuvants could cause bee toxicity.

The EPA has thoroughly reviewed the research and found glyphosate to be practically nontoxic to bees (and humans).  They have found the same for Roundup’s adjuvant polyoxyethylene-alkylamine.  However, some beekeepers tell me that they see increased bee mortality following the spraying of glyphosate (Fig. 3), but are not sure whether it was a generic product, or perhaps contained additional ingredients (surfactants, fungicides, or insecticides) added to the tank mix.

Figure 3

Figure 3. A farmer spraying glyphosate herbicide over Roundup Ready corn seedlings. Photo courtesy of beekeeper Larry Garrett.

Analysis: there is no strong evidence that the spraying of Roundup or generic glyphosate herbicide is directly causing significant bee mortality.  However, Drs. Jim and Maryann Frazier have legitimate concerns about the effect of some adjuvants—especially the organosilicones [27], [28].

Indirect Effects of Roundup Use

Biological plausibility: the elimination of weeds reduces bee forage.

The success of Roundup Ready technology has allowed farmers to largely eliminate weeds from their fields (at least until the inevitable resistant weeds take over).  But they don’t stop there—nowadays they practice “clean farming” and use herbicides to burn off every weed along the fencerows and in the ditches—the very places that bees formerly had their best foraging.  This elimination of flowering weeds severely reduces the amount of available of bee forage, plus kills off the host plants of native pollinators (such as monarch butterflies) and beneficial insects. 

European honey bees evolved in Europe (hence the name), and are adapted to the nutrition provided by Old World flowering plants.  Many of the weeds in North America are old friends of the honey bee.  On the other hand, honey bees were never exposed to corn, soybeans, sunflowers, or squashes until recently; neither corn nor sunflowers supply complete amino acid profiles in their respective pollens.  Until the advent of Roundup Ready, the weeds in an around crops provided alternative nectar and pollen sources for bees; today there is often nary a bee-nutritious weed to be seen in or around a field of corn or soybeans (Fig. 4).

 

Figure 4

Figure 4. I took this photo of a no-till herbicide-resistant corn field, prior to the shading canopy of the crop closing over. Note the total lack of any sort of bee forage (or any species of anything other than corn). The soil surface is a far cry from the original densely vegetated prairie sod. Prior to RR, there was more weedy forage for bees, and especially from the traditional weed-controlling crop rotation into legumes or pasture.

Some intriguing (but controversial) research by Dr. Don Huber [29] concerns the fact that glyphosate was originally developed as a chelating agent (a chemical that binds to metal ions; from chela = claw).  Roundup does not kill weeds directly; rather it ties up certain trace metals (notably manganese), which then stresses the plant to the extent that soil fungi and other pathogens eventually kill it.  Huber’s research found that plants following in rotation after Roundup applications the previous year could be lacking in trace elements due to the residual glyphosate in the soil!  Lack of trace elements causes serious stress and disease in other livestock, and it’s possible that honey bees may also be affected.  The above susceptibility to fungi due to the use of Roundup may then lead to increased application of fungicides, a number of which are demonstrably toxic to bee brood.

But nothing in nature is simple.  Eliminating the competition of weeds and insects may allow plants to hold back from the production of natural toxins.  And a surprising piece of research found corn kernels from plants sprayed with either of two different herbicides actually contain more of the healthful carotenoids [30]!

The Future of Roundup

It took Monsanto several years to genetically engineer Roundup-resistant crops, yet took farmers only slightly longer to inadvertently produce Roundup-resistant weeds by the conventional breeding technique of applying a strong selective pressure–the continuous application of Roundup!

Weed management scientists consider glyphosate to be a once-in-a-100-year discovery—it works on 140 species of weeds, and is relatively environmentally friendly.  However, its overuse has led to the creation of several “driver weeds” that could soon lead to its redundancy in corn, soy, and cotton acreage [31].  This will drive farmers to turn to other herbicides (which will also in time fail).  We can only hope that someday they will be forced back into practicing crop rotation into legumes and pasture.

Reality Check

In order to clarify cause and effect, I often seek out extreme cases.  Such would be the situation in the Corn Belt, where I could compare the USDA’s hive and honey data from the old days to those under today’s intense planting of GM crops (Fig. 5)!

Figure 5

Figure 5. The most intense planting of GM crops is in Iowa and Illinois (the dark green areas of the map above). U.S. farmers planted nearly 100 million acres of corn this year, and 76 million of soy. That is enough acreage to cover the entire state of Texas with GM crops!.
Source: http://www.nass.usda.gov/Charts_and_Maps/Crops_County/pdf/CR-PL10-RGBChor.pdf

So I went through the tedious process of downloading and transcribing the NASS agricultural census figures for Iowa.  I entered the amount of corn acreage, the total number of colonies in the state, and what I consider to be the best measure of colony health—honey yield per hive (which of course is largely weather dependent, but should show any trends).  I plotted the data below (Fig. 6):

Figure 6

Figure 6. Bee and corn data from Iowa, and the dates of introduction of corn pest control technologies. The dotted line is median honey yield per colony. No factor appears to have affected honey production, but colony numbers have decreased since the arrival of varroa. Gaps are missing data. Source NASS.

Over the years, corn acreage increased by 18%.  Other than the prodigious crop of 1988, honey production has averaged around 67 lbs per hive.  The thing that stands out is the plot of number of colonies.  Hive numbers jumped up in the late 1980’s, likely due to federal honey price support payments, which peaked in 1988, and were cut off in 1994 [[i]].  Colony numbers peaked in 1990, the same year that varroa arrived in Ohio, and went down from there, leveling off to about half the number of hives present in the 1970’s.

I fully expected honey yields to decrease concurrent with the adoption of Roundup Ready varieties, but they didn’t!  Colonies still produce as much honey today as they did in the past, but this might be partially due to having fewer bees working the same amount of land, or to increased soybean nectar (which saved a number of Midwestern beekeepers from disaster during this year’s droughts).

Perhaps even more surprising is the fact that in a state covered in corn and soy, colony productivity did not appear to be affected by the introductions of either Bt or Roundup Ready corn, nor by the universal use of neonicotinoid seed treatments (between corn and soy, on over roughly two thirds of the entire state land area).  Note that honey yields actually increased for a few years following the introduction of clothianidin seed treatment! 

Tellingly, hive numbers started to decrease after the arrival of varroa, and plummeted in the late 1990’s as fluvalinate failed as a miticide, and many beekeepers simply threw up their hands and quit the business. 

Verdict on herbicide tolerant crops: from a nutritional standpoint, the increased use of herbicides, and the associated weed free “clean farming” has certainly not helped the bees in corn/soy areas, but it is hard to make a case for them causing colony collapse.

Verdict on GM crops in general:  Allow me to quote from the USDA:

…there is no correlation between where GM crops are planted and the pattern of CCD incidents. Also, GM crops have been widely planted since the late 1990s, but CCD did not appear until 2006. In addition, CCD has been reported in countries that do not allow GM crops to be planted, such as

Switzerland [33].

Looking Ahead:  The Chemical Treadmill & Pest Resistance

It is interesting to observe the evolution of agriculture from the perspective of a biologist.  Simple systems in nature are inherently less stable than complex systems.  The current agricultural model in the U.S. exemplifies simplicity to the extreme—plant a single species into bare soil year after year, killing any competitive weeds or insects with pesticides (either sprayed, systemic, or engineered into the plants), and attempt to maintain fertility by adding energy-costly fertilizer.  From a biological perspective, such a strategy is little more than an intense selective breeding program for the most resistant pests, and doomed to escalating chemical and energy inputs until the system collapses under its own weight.

I’m anything but a salesman for either Bt nor RR crops.  Both are mere short-term solutions—resistant bugs and weeds are already starting to spread.  I also have questions about the benefits of herbicide-intense no till planting [34], and hope that farmers return to alternative methods of weed control [35].  Luckily, the system will likely be self correcting, eventually forcing humanity to practice more sustainable methods of farming the land.  However, I suggest that those methods may well include the wise use of biotechnology. 

Additional Discussion

The Back Story on Plant Breeding and GM Crops

Traditionally, farmers simply replanted with the seeds from the most desirable individual plants year after year; this is the simplest form of “selective breeding.”  For example, all the various cole crops (cabbage, kale, broccoli, cauliflower, kohlrabi, Brussels sprouts) were developed by intentionally selecting for unusual forms of the species (resulting from random recombination of the natural allelic diversity, spontaneous mutants, or natural hybrids).  This sort of selective breeding tends to result in a diverse assembly of locally-adapted cultivars.  In Oaxaca, Mexico– the birthplace of corn–some 150 traditional varieties of maize are grown without pesticides or herbicides, thereby maintaining an invaluable reservoir of genetically-diversity “germplasm,” which breeders can then cross and backcross in order to develop new cultivars (e.g., for pest or drought resistance).

In the early years of the U.S., seeds from desirable cultivars were distributed to farmers by the government, and plant breeding was performed at universities and at the USDA [36].  But since every strain breeds true, a farmer could save the seed and replant, leaving little opportunity for seed companies to make a buck.  So in 1883, they formed the American Seed Trade Association and began to lobby for the cessation of the government programs.

The Profit Motive

In the early part of the 20th century, the companies began to promote hybrids— crosses of two (or more) different strains or species that exhibited some sort of “hybrid vigor”—offering greater production, tastier fruit, or some other desirable characteristic.  Hybrids were a godsend to the companies, since they are often sterile or don’t breed true, meaning that farmers needed to purchase (rather than save) seed each season.

The seed lobby eventually shifted public funding away from the free distribution of selected seedstocks to instead encouraging the USDA and universities to develop inbred parental lines and breeding stock that the seed trade could then use to create proprietary hybrid varieties.  By 1960, farmers planted less than 5% of corn from saved seed; and less than 10% of soybeans by 2001.  As on-farm familiarity with the saving of seed was forgotten, farmers became willing consumers of produced seed.

Enter GM Crops

Then in 1980, the Supreme Court decided that seed companies could patent new varieties if they contained distinct and novel genetic markers.  This meant that farmers (in some countries) could now be required to sign licensing agreements to allow them to use the patented seed each season [37] (there is a hodge-podge of international patent laws in this regard [38]).

The Second “Green Revolution”

The first “green revolution” was based upon fertilizer, pesticides, and hybrid seed (and also resulted in forcing farmers onto “agricultural treadmills”–making them less self sufficient and sustainable, and more reliant upon purchased seed, pesticide and fertilizer use, and upon borrowed money).

In 1950 the Secretary of Agriculture Ezra Benson said to farmers, “Get big or get out.” His 1970s successor, Earl Butts, repeated that message, and exhorted farmers to “plant fence row to fence row” and to “adapt or die.”  Politicians who understood that a well-fed electorate is a happy electorate promoted policies that resulted in the destruction of the small family farm.  Our policy of price supports and favorable treatment of agribusiness has changed the face of the American farm and the composition of the American diet [39].

  Today’s “second green revolution” is based upon technological advances in plant genetics (including GM) and the (at least partial) replacement of nasty pesticides with “biologicals.”  As an environmentalist, I find the new revolution to be more promising for ecological sustainability, but it is not without its downside—the current consolidation of agribusiness.    As I mentioned before, farms, seed companies, and chemical companies are all being bought up by a few main players.  Philip Howard details this consolidation in a free download [40], from which I quote:

This consolidation is associated with a number of impacts that constrain the opportunities for renewable agriculture. Some of these include declining rates of saving and replanting seeds, as firms successfully convince a growing percentage of farmers to purchase their products year after year; a shift in both public and private research toward the most profitable proprietary crops and varieties, but away from the improvement of varieties that farmers can easily replant; and a reduction in seed diversity, as remaining firms eliminate less profitable lines from newly acquired subsidiaries.

He then speaks of the concept of the “treadmill”:

For the majority of farmers, however, the result is that they must constantly increase yields in order to simply maintain the same revenue. [Monsanto’s sales pitch is that economic success in farming is driven by yield per acre [41].  Those that are unable to keep up with this treadmill will fall off,” or exit farming altogether. Their land ends up being cannibalized” by remaining farmers who seek to increase scale of production as another means of keeping up with the treadmill, leading to the increasing centralization of agriculture. Farmers who have managed to stay in business have adapted to this process, and are typically on the leading edge of the adoption of new technologies. As a result, they have a high degree of confidence in science and technological innovations.

However, this problem has nothing to do with GMO’s, but is rather due to the public’s unknowing acceptance of the practice.  Capitalism inevitably leads to consolidation unless consumers stop supporting corporate agribusiness with their pocketbooks and their votes, and start demanding that their government enforce antitrust efforts and better support small farmers. 

But we are allowing economics and politics to distract us from the topic at hand—the technology of genetic engineering in plant breeding.

Cautions About GM

The most vocal critic of genetic modification is Jeffrey Smith, fear-mongering author of Seeds of Deception, producer of the film Genetic Roulette, and executive director of the inappropriately-named Institute for Responsible Technology. Smith is a gifted and effective communicator, as well as being a practitioner of “yogic flying” [42].  I will be the first to say that Smith’s anti-GMO claims [43] would scare the pants off of anyone, and make for compelling story!  The problem is that he plays loose with the facts—most of his claims simply do not stand up to any sort of scientific scrutiny.  I suggest that for an objective analysis of the facts, that you visit AcademicsReviewed.org, a website that tests popular claims against peer-reviewed science.  They address each of Smith’s alarming “facts” one by one [44].  It is a thrilling ride to open the two web pages side by side, first being shocked by Smith’s wild and scary claims, and then reading the factual rebuttal to each!  The thing that most bothers me about Smith’s writing is that he treats GM cultivars generically, rather than specifically addressing the merits or concerns for them individually.  This makes little sense, since any conventional crop has cultivars that cause human allergy or contain excessive levels of natural toxins, yet no one calls for the testing of each of them!

Perspectives On GM Crops

As you may have guessed by now, to me, the GM debate should not be about being pro or con, rather it should be about the intelligent discussion of reconciling its promise with its problems.  The GE genie is out of the bottle, and I can’t see that anyone is going to put it back in–so we might as well work with it!  So let’s cut through the hype and hysteria, the fears and judgments, and try to objectively look at the facts of the matter:

  1. From a plant breeder standpoint, genetic engineering holds incredible promise for the development of crops that could be tremendously beneficial to humans or the environment.  For example, “Transgenic cotton has reduced the need for conventional insecticides used against lepidopteran [pests] an average in the USA about 59.4% [and] Texas 74.7%…an average number of pesticide applications in conventional cotton has fallen from 4.3 in 1995 to 2.1 in the USA… with benefits to human health and the environment” [45].
  2. GM is only a part of plant breeding—most advances continue to be in conventional breeding, now assisted by “marker assisted selection,” which is embraced by environmentalists [46].
  3. However, someone needs to pay for the research, and the taxpayer is not doing it!  For a thoughtful discussion of the benefits of gene patents, see [47].
  4. Novel genetic markers can be patented, and a licensing fee can be charged, despite the fact that they are not GM!
  5. From a consumer standpoint, advanced breeding techniques can result in cheaper and more nutritious food, and less environmental impact from farming. 
  6. Consumers have erroneously been led to believe that GM crops are dangerous to their health, and call for application of the precautionary principle.  My gosh, please read “Misconceptions about the causes of cancer” [48].  Few foods are entirely “safe”!  And “safety” can never be proven—it can only be disproven.  And no studies have ever disproven the safety of GM crops, nor have doctors noticed anyone ever getting sick from them, despite our eating them for 15 years!
  7. In truth, some scientists argue that plants produced by classical breeding methods should undergo the same safety testing regime as genetically modified plants. There have been plenty of instances where plants bred using classical techniques have been unsuitable for human consumption, causing toxicity or allergic reactions.
  8. Those that speak of applying the “precautionary principle” should read Jon Entine’s trenchant analysis of the fallacy of overapplication of that principle [49].  In truth, our regulators (EPA and FDA) vigorously apply the precautionary principle in the form “reasonable certainty of no harm.”
  9. The benefits of seed biotechnology cannot be realized without good seed germplasm to start with.  So a few large seed companies started buying up their competitors to acquire the most productive and desirable varieties. 
  10. The downside of the above practice is that by 2008, 85% of GM maize patents and 70% of non-maize GM plant patents in the U.S. were owned by the top three seed companies: Monsanto, DuPont, and Syngenta [50].  Note that economists figure that when four firms control 40% of a market, it is no longer competitive; in the case of GE crops, the top four seed firms control 56% of the global proprietary seed market! 
  11. On the flip side, these profits are an incentive for the large corporations to invest in innovative plant breeding research—Monsanto spends about $2 million a day on this.  This is important to keep in mind in an increasingly hungry world.
  12. On the dark side, Monsanto’s nearly $12 billion in annual sales allows the company to lobby regulators, influence universities, and spin the news.  These are standard business practices for any large corporation, but hardly make Monsanto uniquely evil.
  13. Be aware that patented genes are of use only if inserted into high-producing cultivars–which are developed by conventional breeding (which constitutes nearly half of Monsanto’s plant breeding budget).  These desirable cultivars have no patent protection.  Monsanto uses a non GE technology called SMART = Selection with Markers and Advanced Reproductive Technologies.  SMART technology is warmly embraced by environmental groups [51].
  14. Adding a genetic marker allows a company to identify its proprietary strains, like putting a nametag on a dog.  But clever breeders can back engineer the desirable germplasm out from patent protection. 
  15. And remember that patents expire after 20 years.  The patents for Roundup Ready soybeans expire in 2014—at which time farmers, universities, and seed companies will then be free to propagate and sell the variety [52].  Patents are granted in order to spur innovation; by filing for patent protection, a company must make its discoveries public knowledge.  This is a good thing. 
  16. Monsanto  invests 44% of its R&D on conventional (as opposed to GM breeding). 
  17. Monsanto has also given rights to some of their patented crops to poorer countries, and recently donated a database of some 4000 genetic markers from cotton to Texas A&M [53].  The university plant breeders are excited in that the information will assist them in their conventional (non-GM) breeding of cotton, to the benefit of the environment [54 ].
  18. From the farmer’s standpoint, he has the choice of purchasing GE varieties that may be more productive, reduce insecticide use, or reduce tillage costs [55].  Keep in mind that there is nothing keeping him from purchasing “conventional” non-GM seed—it is available (I checked, and it sells at about half the cost of GM seed).  In our free enterprise system there is nothing to keep non-GM seed companies from selling an alternative product if there is a demand.  Farmers who are unimpressed by GM varieties freely switch back to conventional seed.
  19. From an agricultural standpoint, the widespread adoption of a few favored crop varieties (GM or not) can result in the irreplaceable loss of crop genetic diversity—this is of great concern to plant breeders.  If you haven’t yet seen the graphic of our loss of crop genetic diversity from National Geographic magazine, you should! [56].  Luckily, this does not appear to be occurring yet with maize in Oaxaca [57], but there is a legitimate concern that economics will force traditional farmers out of business, leading to the loss of heirloom varieties.  However, this is not a GM issue, but rather an effect of consolidation.
  20. From a sustainability standpoint, there is nothing to prevent constant breeding innovation to keep pace with pest evolution.  Genetically engineered crops can play a role in sustainable farming as our agricultural practices begin to shift to more ecologically sustainable methods.
  21. One should keep in mind how the simple splicing of a virus gene into the papaya saved the Hawaiian papaya growers from the ravages of ringspot virus—the GE papaya is the mainstay of the industry, and by virtue of keeping the virus in check actually allows nearby organic papayas to thrive.  Yet ecoterrorists recently hacked down thousands of GM trees [58].  It’s interesting to read the history of “Golden Rice” [59] to see how the anti-GMO lobby is specifically scared that the success of such a lifesaving crop might open the door for acceptance of other GM plants!

Update Jan 2013

News item: Leading Environmental Activist’s Blunt Confession: I Was Completely Wrong To Oppose GMOs. Blog in Slate Magazine

“If you fear genetically modified food, you may have Mark Lynas to thank. By his own reckoning, British environmentalist helped spur the anti-GMO movement in the mid-‘90s, arguing as recently at 2008 that big corporations’ selfish greed would threaten the health of both people and the Earth. Thanks to the efforts of Lynas and people like him, governments around the world—especially in Western Europe, Asia, and Africa—have hobbled GM research, and NGOs like Greenpeace have spurned donations of genetically modified foods.

But Lynas has changed his mind—and he’s not being quiet about it. On Thursday at the Oxford Farming Conference, Lynas delivered a blunt address: He got GMOs wrong.”

Anyone opposed to GMO’s should read Mr. Lynas’ well thought out address: http://www.marklynas.org/2013/01/lecture-to-oxford-farming-conference-3-january-2013/

Update May 2014

I’ve compiled a list of recent worthwhile reading on the “other side” of the GMO debate at http://scientificbeekeeping.com/gmo-updates/

So What’s The Problem?

The problem is that anti-GMO advocacy groups are determined to put a stop to all GE technology.  They targeted California with Prop 37, which applied only to packaged foods and produce.  A more cynical take on Prop 37 was that it was all about marketing: “If your produce is no different in terms of taste, safety and nutrition from a competitor, and costs more, apparently the only marketing option is to create a negative image of your competitor’s product” [60].

If Prop 37 had been successful, the promoters would then have targeted restaurants, the meat and dairy industry, and the beverage industry.  I personally feel that this is an extreme position, what with the human population growing hungrier every day, and climate change threatening agriculture worldwide with heat, drought, pestilence, and salinity problems.  Not only that, but GM crops hold promise for cheap omega-3 fatty acids (so that we don’t have to harvest fish for them), cost-effective biofuels, and less expensive pharmaceuticals.

A good blog on the problem with the anti-GMO fear campaign can be found at [61], from which I quote:

It would be bad enough if something like the Seralini study simply contributed to the unnecessary angst amongst consumers around the world.  It also has very real political, economic and practical effects.  For instance brand conscious food companies have used their leverage to prevent the development of GMO versions of potatoes, bananas, coffee and other crops because they fear controversy.  Apple growers worried about the market response are opposing the introduction of a non-browning apple even though it was developed by one of their own fruit companies.  French activists destroyed a government-run field trial of a virus-resistant root stock which could have made it possible to produce good wine on sites that have become useless because of contamination with sting nematodes and the virus they vector.  California voters have the potential to pass a seriously flawed “GMO labeling” initiative next month that could only serve the purposes of the lawyers and “natural products” marketers who created it.  More importantly, European and Japanese importers of wheat essentially blackmailed the North American wheat producers into blocking biotech wheat development because those companies were nervous about consumer response in countries where GMO angst is so high.  This has delayed by decades not only specific desirable trait development, but also what might have been an enormous private investment in a crop that is critically important for feeding a lot more people than just those in those rich countries.  There is a huge cost of “precaution” based on poor science.

I believe that people should be well informed before taking a stance on important issues.  I’d like to suggest one last excellent blog by an independent U.C. Berkeley evolutionary biologist and medical researcher:“How Bt Corn and Roundup Ready Soy Work – And Why They Should Not Scare You [62].

Acknowledgements

As always, thanks to my friend and collaborator in research Peter Loring Borst, and to anyone who still reads my articles after finding out that I’ve collaborated with Monsanto!

References

[1]  Key S, et al (2008) Genetically modified plants and human health. J R Soc Med.101(6):290-298. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2408621/

[2] For example: Antoniou, M, et al (2012) GMO myths and truths.

http://earthopensource.org/files/pdfs/GMO_Myths_and_Truths/GMO_Myths_and_Truths_1.3.pdf

[3] Chiba S, et al. (2011) Widespread endogenization of genome sequences of non-retroviral RNA viruses into plant genomes. PLoS Pathog 7(7): e1002146.

[4]  Domingo, JL and JG Bordonaba (2011) A literature review on the safety assessment of genetically modified plants. Environment International 37: 734–742.

[5] Key (2008) op. cit.

[6] Smith, JM (2003) Seeds of Deception.  Yes! Books

[7] Séralini, GE, et al  (2012)  Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize. Food and Chemical Toxicology (2012) http://foodpoisoningbulletin.com/wp-content/uploads/Toxicity-of-Roundup-Ready-Maize.pdf;

Reviews

http://www.forbes.com/sites/henrymiller/2012/09/25/scientists-smell-a-rat-in-fraudulent-genetic-engineering-study/2/

http://www.efsa.europa.eu/en/faqs/faqseralini.htm#9, http://www.emilywillinghamphd.com/2012/09/was-it-gmos-or-bpa-that-did-in-those.html,

http://www.ask-force.org/web/Seralini/Anonymous-Rat-List-Spaying-2003.pdfs, http://storify.com/vJayByrne/was-seralini-gmo-study-designed-to-generate-negati

Benbrook, CM (2012) Impacts of genetically engineered crops on pesticide use in the U.S. — the first sixteen years.  Environmental Sciences Europe 24:24 http://www.enveurope.com/content/pdf/2190-4715-24-24.pdf,

Review http://weedcontrolfreaks.com/2012/10/do-genetically-engineered-crops-really-increase-herbicide-use/#more-432

[8]  http://journals.tubitak.gov.tr/agriculture/issues/tar-04-28-6/tar-28-6-1-0309-5.pdf

[9] http://www.monsanto.com/whoweare/Pages/monsanto-history.aspx

[10]  http://www.businessweek.com/stories/2010-01-10/monsanto-v-dot-food-inc-dot-over-how-to-feed-the-world

[11]  Methods for genetic control of plant pest infestation and compositions thereof

http://www.freepatentsonline.com/8088976.html 

http://www.freepatentsonline.com/7943819.html

[12]  http://www.greenpeace.org/australia/PageFiles/348427/smart-breeding.pdf

[13] 2007 figures http://www.census.gov/compendia/statab/2012/tables/12s0835.pdf

[14] ETC Group (2008) Who owns nature? Corporate power and the final frontier in the commodification of life. http://www.etcgroup.org/sites/www.etcgroup.org/files/publication/707/01/etc_won_report_final_color.pdf

[15]  Blakeney, M (2011) Trends in intellectual property rights relating to genetic resources for food and agriculture. http://www.fao.org/docrep/meeting/022/mb684e.pdf This document covers the hodge-podge of international patent laws regarding plants and animals.

[16] http://www.monsanto.com/products/Pages/biodirect-ag-biologicals.aspx

[17] History of Bt  http://www.bt.ucsd.edu/bt_history.html

Mode of action http://www.bt.ucsd.edu/how_bt_work.html

[18] Gold 2002 Misconceptions about the causes of cancer http://potency.berkeley.edu/pdfs/Gold_Misconceptions.pdf A “MUST READ”!

[19]  Buchmann CA, et al (2007) Dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) and 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA), two naturally occurring benzoxazinones contained in sprouts of Gramineae are potent aneugens in human-derived liver cells (HepG2).  Cancer Lett. 246 (1-2):290-9.

[20]  http://en.wikipedia.org/wiki/Endophyte

[21] Duan JJ, et al (2008) A meta-analysis of effects of Bt crops on honey bees (Hymenoptera: Apidae). PLoS ONE 3(1): e1415.

[22]  Center for Environmental Risk Assessment (2011) A review of the environmental safety of the Cry1Ab protein. http://cera-gmc.org/docs/cera_publications/cry1ab_en.pdf

[23] Han, P, et al (2012) Does transgenic Cry1Ac + CpTI cotton pollen affect hypopharyngeal gland development and midgut proteolytic enzyme activity in the honey bee Apis mellifera L. (Hymenoptera, Apidae)?  Ecotoxicology. 2012 Aug 7. [Epub ahead of print]

[24]  Hendriksma HP, et al (2011) Testing pollen of single and stacked insect-resistant bt-maize on in vitro reared honey bee larvae. PLoS ONE 6(12): e28174.

[25] Benbrook, CM (2012) op. cit.

[26] Reviewed in http://www.sourcewatch.org/index.php/Glyphosate

[27] Mullin, C.A., J.L. Frazier, M.T. Frazier & T.J. Ciarlo – A primer on pesticide formulation ‘inerts’ and honey bees.  http://www.extension.org/pages/58650/proceedings-of-the-american-bee-research-conference-2011

[28] Ciarlo TJ, CA Mullin, JL Frazier, DR Schmehl (2012) Learning impairment in honey bees caused by agricultural spray adjuvants. PLoS ONE 7(7): e40848.

[29] Johal, GS and DM Huber (2009)  Glyphosate effects on diseases of plants.  Europ. J. Agronomy 31: 144–152.  http://www.organicconsumers.org/documents/huber-glyphosates-2009.pdf

Huber, DM (2010) Ag chemical and crop nutrient interactions – current update.  http://www.calciumproducts.com/dealer_resources/Huber.pdf

Reviewed in http://www.weeds.iastate.edu/mgmt/2010/glyMndisease.pdf

[30] Kopsell et al. (2009) increase in nutritionally important sweet corn kernel carotenoids following mesotrione and atrazine applications.  Journal of Agricultural and Food Chemistry 090619124509017 DOI: 10.1021/jf9013313

[31]  Laws, F (2010) http://cornandsoybeandigest.com/issues/will-glyphosate-fall-wayside-resistance-grows

[32]  http://www.nationalaglawcenter.org/assets/crs/RS20759.pdf

[33]  http://www.ars.usda.gov/is/AR/archive/jul12/July2012.pdf

[34]  http://www.misereor.org/fileadmin/redaktion/MISEREOR_no%20till.pdf

[35]  http://www.acresusa.com/toolbox/reprints/Organic%20weed%20control_aug02.pdf

[36] http://www.seedalliance.org/Seed_News/SeminisMonsanto/

[37] http://earthopensource.org/files/pdfs/GMO_Myths_and_Truths/GMO_Myths_and_Truths_1.3a.pdf

[38]  Blakeney, M (2011) Trends in intellectual property rights relating to genetic resources for food and agriculture. http://www.fao.org/docrep/meeting/022/mb684e.pdf This document covers the debate involved in international patent law regarding plants and animals.

[39] Philpott, T (2008) A reflection on the lasting legacy of 1970s USDA Secretary Earl Butz. http://grist.org/article/the-butz-stops-here/; but for a contrary view by an actual corn farmer, read Hurst, B (2010) No Butz About It. http://www.american.com/archive/2010/july/no-butz-about-it

[40] Howard, Philip H. 2009. Visualizing consolidation in the global seed industry: 1996–2008. Sustainability, 1(4), 1266-1287. http://www.mdpi.com/2071-1050/1/4/1266/pdf

[41] http://www.monsanto.com/investors/Documents/Whistle%20Stop%20Tour%20VI%20-%20Aug%202012/WST-Fraley_RD_Update.pdf

[42] http://academicsreview.org/reviewed-individuals/jeffrey-smith/

[43] http://responsibletechnology.org/docs/145.pdf

[44] http://academicsreview.org/reviewed-content/genetic-roulette/

[45] Greenberg, S, et al (2012) Economic and Environmental Impact Transgenically Modified Cotton Comparative with Synthetic Chemicals for Insect Control. Journal of Agricultural Science and Technology B 2 750-757.

[46] Greenpeace (2009) Smart Breeding.  Marker-Assisted Selection: A non-invasive biotechnology alternative to genetic engineering of plant varieties.  http://www.greenpeace.org/australia/PageFiles/348427/smart-breeding.pdf

[47] http://www.genengnews.com/gen-articles/in-defense-of-gene-patenting/2052/

[48]  Gold 2002 Misconceptions about the causes of cancer http://potency.berkeley.edu/pdfs/Gold_Misconceptions.pdf

[49] Entine, J (2010) Crop Chemophobia: Will Precaution Kill the Green Revolution? http://www.jonentine.com/pdf/CROPCHEMOPHOBIApre-orderform.pdf

[50] Howard, Philip H. 2009. Visualizing consolidation in the global seed industry: 1996–2008. Sustainability, 1(4), 1266-1287. http://www.mdpi.com/2071-1050/1/4/1266/pdf

[51] http://www.greenpeace.org/australia/PageFiles/348427/smart-breeding.pdf

[52] http://www.monsanto.com/newsviews/Pages/roundup-ready-patent-expiration.aspx;

[53] http://www.cotton247.com/article/3401/monsanto-donates-marker-technology

[54] http://www.youtube.com/watch?v=dcZyFH_eITQ

[55] http://www.biofortified.org/2012/05/the-frustrating-lot-of-the-american-sweet-corn-grower/#more-8670

[56] http://ngm.nationalgeographic.com/2011/07/food-ark/food-variety-graphic If you didn’t see this graphic in National Geographic, you should!

[57]  http://researchnews.osu.edu/archive/mexmaize.htm

[58] http://www.huffingtonpost.com/2011/08/20/genetically-modified-papayas-attacked_n_932152.html

[59]  http://en.wikipedia.org/wiki/Golden_rice

[60] http://westernfarmpress.com/blog/proposition-37-gone-probably-not-forgotten?

[61]  http://appliedmythology.blogspot.com/2012/10/can-damage-from-agenda-driven-junk.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+AppliedMythology+%28Applied+Mythology%29

[62] http://www.science20.com/michael_eisen/how_bt_corn_and_roundup_ready_soy_work_and_why_they_should_not_scare_you

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