Tag Archives: GMO

Are GMOs Safe? Global Independent Science Organizations Weigh In


Jon Entine at  the Genetic Literacy Project has released a very useful infographic on crop biotechnology safety. This is a summary of the unambiguous safety approvals of every national scientific academy on the planet.

This is the second inforgraphic from GLP. The first is also very useful, 10 reasons we need crop biotechnology


Mark Lynas: Using the tools of biotechnology to advance Borlaug’s legacy

Don’t miss the recent keynote speech by Mark Lynas to the Borlaug Global Rust Initiative 2013 Technical Workshop, New Delhi. Norman Borlaug would be proud. Excerpts:

We are gathered here today, under the aegis of an international collaboration that bears his name, to continue Borlaug’s lifelong battle with wheat rust. Rust wiped out his family farm’s wheat when he was a boy, and rust was the reason Borlaug initially established the research station in Sonora.

As we all know, he and his colleagues succeeded eventually in defeating wheat stem rust for many decades, until the emergence of the resistant race Ug99 at the very end of the last century.

Although the progress of Ug99 has not been as dramatic as initially feared, susceptible wheat is still being grown all over the world, and forms a mainstay of humanity’s food supply today. A fifth of all our calories come from wheat, and the global harvest is nearly 700 million tonnes per year.

While European wheat growers keep stem rust at bay with liberal applications of fungicide, this is neither ecologically sustainable nor financially desirable over the longer term.

In south and east Asia, meanwhile, both of which produce more wheat than the whole of North America, most growers cannot afford or do not have access to fungicides.

Billions of people therefore depend on susceptible wheat varieties that are sitting ducks, waiting for an epidemic of Ug99 to be blown over on the winds from the Middle East and Africa.

I was given the mandate to talk today about ‘Using the tools of biotechnology to advance Borlaug’s legacy’, and I cannot imagine a more appropriate area where this applies than the question of tackling wheat stem rust.

Borlaug was an unusual revolutionary in that he didn’t want his revolution to stop with him. He was a lifelong advocate of innovation – and a staunch supporter of biotechnology as the promising new frontier for plant breeding.

You can see why. By today’s standards, Borlaug had to work blind, using guesswork, chance and a lengthy process of elimination with thousands upon thousands of wheat crosses to try to get just the right genetic combination.

I cannot imagine a better embodiment of Norman Borlaug’s philosophy than this successful joint effort.


But unfortunately the progress of good science runs up against the hard rock of bad politics. As perhaps the world’s most political food crop, by virtue of its very nature in supplying our daily bread, wheat has so far been locked out of the biotechnology revolution.

Although many new wheats have been developed using recombinant DNA and even tested in field trials, not a single one has ever been made available to farmers – not because there was anything wrong with the new varieties, but solely because of the worldwide cloud of fear and superstition that surrounds the use of genetic engineering.

Thus, the most powerful tools offered by modern molecular biotechnology must seemingly be permanently discarded – not because of any rational assessment of risks and benefits – but because a tide of anti-science activism has drowned scientists and governments around the whole world in a tsunami of lies.

The Myth and Reality of Terminator Seeds

Farmers have historically been glad to buy seeds from seed companies. Seed companies specialize in making seeds, not making food. Farmers specialize in growing food, not seeds. Seed companies can grow plants/seeds to maturity, harvest at the right time, process and store the seed, then perform quality control to guarantee the best product for the farmer.

University of Florida plant scientist Kevin Folta recently posted a very concise puncturing of a favorite myth of the anti-GMO activists: 

The topic of ‘suicide seeds’ or ‘terminator technology’ is a deeply engrained in the fabric of the anti-GMO movement.Suchominouslanguage is the basis of many websites thatconjure fear spanning from farmer manipulation to the death of every plant on the planet. That would be one heck of a frankenfood!

 Sticking a loaded gun in the ear is a sure way to develop vivid misinformation.

However, the reality is not nearly so scary. In 1998 Delta and Pine Land, one of America’s largest cotton seed company, recieved wide patent protection for a series of traits, one that was called’technology protection system’. Through a ratherclever process a self-fertilizing plant cannot produce germinating seeds. The molecular basis is a gene that encodes a protein called a Ribosome Interferring Protein. You might recall that ribosomes are the cellular sites for protein synthesis, so ifthis interferring protein is expressed, the plant can’t make otherproteins (which comprise enzymes and structural feature) so the plant would die before germination.

The gene was placednext to a promoterfrom an LEA gene. Think of promoters as on-off switches. LEA stands for ‘Late Embryogenesis Abundant’. So this promoter switcheson the protein that interrupts protein synthesis during late embroygenesis. Anembryo that can’t synthesize protein is pretty much DOA.

All of this was regulated through a clever but complex process that activated this mechanism upon self-pollination. If you’d like to know more send me an email. I could go into detail here, but a picture is worth 1000 words. Probably more.

Why do they callit ‘terminator technology’? This term actuallywas devised from a Canadia NGO called theRural AdvancementFoundation International. They were not so excited about the technology.

But to your point, how does this technology help farmers? It doesn’t. It doesn’t hurt them either.Why? Because it was never used in a crop beyond the greenhouse. The technology was never commercially deployed. Why not? Probably because itbecame a PR nightmare coupled tothe fact that Delta Pine’s products had a long, expensive road to deregulation ahead.


There is much more detail at Kevin’s blog.

A Race to Save the Orange by Altering Its DNA

Here is an unusually well-researched NYT article on the efforts to control citrus greening. The obvious solution is to apply modern plant genetics to develop a commercial orange that is resistant to the bacterium. Southern Gardens Citrus has been funding five labs that are making excellent progress on GM solutions. But the delays in the tortuous regulatory jungle may have less financial impact on growers than the unfounded fears that have been spread by anti-GMO activists. Could the Greenpeace campaign against modern agriculture end up destroying the Florida orange industry?

The call Ricke Kress and every other citrus grower in Florida dreaded came while he was driving.

“It’s here” was all his grove manager needed to say to force him over to the side of the road.

The disease that sours oranges and leaves them half green, already ravaging citrus crops across the world, had reached the state’s storied groves. Mr. Kress, the president of Southern Gardens Citrus, in charge of two and a half million orange trees and a factory that squeezes juice for Tropicana and Florida’s Natural, sat in silence for several long moments.

“O.K.,” he said finally on that fall day in 2005, “let’s make a plan.”

In the years that followed, he and the 8,000 other Florida growers who supply most of the nation’s orange juice poured everything they had into fighting the disease they call citrus greening.

To slow the spread of the bacterium that causes the scourge, they chopped down hundreds of thousands of infected trees and sprayed an expanding array of pesticides on the winged insect that carries it. But the contagion could not be contained.


In his office is a list of groups to contact when the first G.M.O. fruit in Florida are ready to pick: environmental organizations, consumer advocates and others. Exactly what he would say when he finally contacted them, he did not know. Whether anyone would drink the juice from his genetically modified oranges, he did not know.

But he had decided to move ahead.

Late this summer he will plant several hundred more young trees with the spinach gene, in a new greenhouse. In two years, if he wins regulatory approval, they will be ready to go into the ground. The trees could be the first to produce juice for sale in five years or so.

Whether it is his transgenic tree, or someone else’s, he believed, Florida growers will soon have trees that could produce juice without fear of its being sour, or in short supply.


GM cotton protects insect predators

Editor's summary

Transgenic crops producing insecticidal proteins derived from Bacillus thuringiensis (Bt) have proved effective in controlling bollworm and reducing the need for pesticides in cotton crops in China. This study of Bt crop performance at sites across northern China identifies a decrease in aphid pests and a marked increase in the numbers of ladybirds, lacewings and spiders — natural enemies of insect pests — compared with conventional crops. There is also evidence that these predators thrive in neighbouring non-transgenic maize, soyabean and peanut crops. These results suggest that Bt cotton can promote biological control in agricultural ecosystems by decreasing insecticide use and increasing predator populations.

LSE Enters the GMO Discussion

Very interesting! Cami Ryan linked to this Agri-Pulse bulletin on the new report entitled “Feeding the Planet in a Warming World.” I just downloaded the report:

© Copyright Agri-Pulse Communications, Inc.

The prestigious London School of Economics (LSE) and the Information Technology and Innovation Foundation and have entered the GMO discussion with a new report entitled “Feeding the Planet in a Warming World.” With the 39th G-8 summit to be held in Northern Ireland June 17-18, the LSE report is quite timely and significant. The agenda for the upcoming meeting established by Prime Minister David Cameron will continue the discussion of global food security started by President Obama last year at Camp David.

The LSE report offers insight and possible solutions to mitigating the rapidly growing challenge of global food security. Therefore, allow me to quote from the Executive Summary at some length:

“Even in the most ideal circumstances, diffusing existing agricultural technologies and practices is not enough to address the challenges we will face in the coming decades. In light of this, we propose several solutions. In particular, we argue that the critical, game changing solutions for building global agricultural resilience will come only from expanding the innovation and adoption of next-generation crops and agricultural practices. We need new and improved crop varieties that use less water, deliver increased yields and improved nutrition, and have built-in means for repelling insect pests, resisting disease, and withstanding extreme heat, cold, rain and drought. Agriculture will need every existing tool in the box, as well as the development of new ones, including the use of demonstrably safe crops improved through modern biotechnology, commonly referred to as genetically modified organisms (GMOs) or transgenics…

Governments worldwide should reform GMO regulations. There is no agricultural policy change that could be adopted with more positive impacts and fewer downsides than drastically reducing regulations applied to crops improved through biotechnology. Foods derived from crops or animals improved through biotechnology have been subjected to more extensive scrutiny than any other agricultural product in human history. Humans and livestock have consumed billions upon billions of meals derived wholly or in part from these improved agricultural varieties for nearly two decades, which have sustained a strong record of safety for humans and the environment. Yet these innovative products, which are developed and brought to market with precise, predictable and safe techniques, are subjected to regulatory obstacles that dwarf those faced by older products and obsolete technologies, some with genuinely problematic legacies.”



Survey of Pest resistance to Bt crops

Jonas Kathage has posted a very approachable survey of Bt resistance issues and strategies at Biology Fortified, Inc. Jonas closes with the following discussion of both economics and resistance management strategies:

Meanwhile, entomologists are working on improving their incomplete understanding the complex mechanisms involved in resistance evolution. Recently published research suggests that pyramiding might not work as well in delaying resistance as previously thought. In the laboratory, scientists selected cotton bollworm (Helicoverpa zea) for resistance against Cry1Ac. They exposed the resistant insects and a susceptible control group to Bt cotton expressing Cry1Ac/Cry2Ab and found that the group resistant to Cry1Ac exhibited a much higher survival rate than the control group, violating the assumption of redundant killing that is crucial to this strategy. So far, despite multiple reported instances of resistant insects, large-scale failure of Bt crops due to evolved resistance has not occurred, but it may come sooner than expected.

Should refuge requirements be expanded?

This research finding is bad news because the potential of pyramided Bt crops might be lower than believed. (Actually, some scientists have been positively surprised at the long delays observed in resistance development.) Let’s assume the results also apply to other Bt pyramids and insect species (there is evidence to the contrary). What should be made of such a scenario? Should larger refuge areas be required?

Before answering that question, it must be recognized that the sustainable application of a particular technology is not a primary goal of farming. A much more important goal is efficiency. Efficiency means getting the most output (e.g. food) from a set of scarce inputs (natural resources, labor, capital). The technologies transforming inputs into outputs, be they biological, chemical, or mechanical, are valuable only insofar as they contribute towards efficiency.

When deciding whether to expand refuge requirements, policymakers must take into account that there is a tradeoff between the size of the refuge area and productivity. If refuge area increases, more plants will get damaged by pests and hence reduce effective yield. The crucial question is whether the benefits of delaying resistance outweigh the costs of these yield losses and other potential drawbacks of refuges such as the need for additional land, sprays, separation costs, and sowing and harvest times. Costs of monitoring compliance with refuge requirements must also be considered, while pyramiding will incur more R&D expenditures. (In some developing countries with larger monitoring costs, refuge requirements may be less efficient also because of natural refuge in small-scale cropping systems.) The point here is not to question whether the optimal refuge requirement is 0%, 20% or 40%, but to realize that there are costs that have to be weighed against benefits. It is possible that an arms race based on adding more Bt genes is more efficient than slowing resistance development by expanding mandated refuges.

Besides Bt crops, there is a host of other pest management options including chemical control, biological control and cultural control such as ploughing and crop rotation. Like Bt, they all have their particular drawbacks, be it risk of resistance development, low effectiveness, or environmental and economic cost. The most efficient pest management strategy depends on local context, but will involve multiple instruments. For breeders, genes producing insect toxins, whether introduced using conventional or GM techniques, are not the only route towards pest protection. There are exciting possibilities on the horizon, including transgenic plants that emit volatile organic compounds to repel herbivores or attract their natural enemies. The use of nano-silica that kill pests by purely physical means are just one example of potential applications of nanotechnology in pest management. New approaches will have benefits and costs to be assessed against existing alternatives. As of today, there are no magic bullets protecting crops from pests. But there are excellent reasons that we should keep looking for them. Bt will not be the end of the road.

Continue reading from the top…


Switzerland Creates Secure Test Site for GM Crops

…Swiss researchers running recent GM trials spent 78% of their research funds on security. 

That is shocking – almost 80% of scarce Swiss research funds are wasted to prevent criminals such as Greenpeace from destroying research that benefits everyone – research which especially benefiits the Bottom Billion. Well, the Swiss government is going implement a more efficient centralized security scheme at the Reckenholz research station near Zurich. The goal is remove the drain of security expenditures from research grants – distributing the cost to all taxpayers. Sadly it won’t eliminate the need for the security in the first place.  

(…) GM crops are controversial in Europe, and European law requires scientists to notify the public about the precise locations of the fields where they are running experiments. This has led to protests and sometimes vandalism at more than 100 European trials since 2010. One result is that the number of GM field experiments conducted in the European Union dropped from about 250 per year in the late 1990s to fewer than 50 in 2011, the researchers report. In Switzerland, researchers have submitted just six applications for field experiments with GM plants since the late 1990s; authorities rejected two in 1999 because “the social and environmental impacts compared to any possible economic benefits were clearly too high.”

In a bid to make such experiments easier, the Swiss Federal Council approved spending €600,000 annually from 2014 to 2017 to create a protected field site of approximately three hectares at the Reckenholz research station, 10 kilometers north of Zurich. Researchers will initially use it to test GM wheat with resistance to powdery mildew, a fungal disease, but they could ultimately plant other crops such as potatoes. 

Every attack by the masked vandals is a crime against humanity. I wonder if criminal prosecution of Greenpeace in all of the OECD would stop this nonsense? Possibly not – as Greenpeace is so successful with fund-raising based upon blocking evil GMO and evil nuclear power.

Mark Lynas interviews geneticist prof. Nina Fedoroff: anti-GMO claims are just plain false

Mark Lynas interviews top geneticist Nina Fedoroff. This is a terrific, authoritative rebuttal of all the main talking points of Mark's critics on the anti-GMO side. Be sure to read the comments section — there are the expected anti-GMO trolls, followed by evidence-bases rebuttals by people who know.

Dr. Nina Fedoroff is a leading geneticist and molecular biologist and a Distinguished Professor of Biosciences at the King Abdullah University of Science and Technology in Saudi Arabia, where she is establishing a new Centre for Desert Agriculture. She is also an Evan Pugh Professor at Penn State University. She has contributed to the development of modern techniques used to study and genetically modify plants. From August 2007 to July 2010, she served as the Science and Technology Adviser to the US Secretary of State and to the Administrator of the US Agency for International Development (USAID). Dr. Fedoroff is a member of the National Academy of Sciences and the European Academy of Sciences, and is also a 2006 National Medal of Science laureate, the highest scientific honour that can be bestowed by the United States government. She was AAAS President in 2012 and is currently Chair of the AAAS Board of Directors.

Questions (by Mark Lynas):

1. You have read my speech to the Oxford Farming Conference. While it has attracted a lot of worldwide attention and support, it has also been attacked by some who make great play of their scientific credentials but who do not seem to actually be active in the plant science/molecular biology field. Since you are highly distinguished in this area, and indeed one of the pioneers of the field of transgenics, is there anything you think I got wrong which should be highlighted?

Professor Fedoroff:

“But what about mixing genes between unrelated species? The fish and the tomato? Turns out viruses do that all the time, as do plants and insects and even us – it’s called gene flow.” (Mark Lynas speech to Oxford Farming Conference)

This is a bit of an exaggeration. There is more mixing between species through horizontal transfer (viruses and such) than we used to think happens, but it isn’t all that common. The real answer to the question is that genes are simply instructions for making a protein and they aren’t either “fishy” or “tomatoey.” The rules for making proteins are the same in all organisms, so if you express a gene in another species, it will do the same thing it did in the first place. So the fish gene for a protein that inhibits ice crystal formation would make the tomato a little more resistant to below-freezing temperature, but it won’t make the tomato fishy.

This is a relatively minor point. On balance, you got most of the most important issues and you got them right. I particularly enjoyed your assessment of the organic movement – a huge commercial hoax.

2. As 2012 President of the American Association for the Advancement of Science, and current Chair of the Board of Directors, you are in a good position to help laypeople understand what the real scientific consensus is on GMOs. For instance, the Union of Concerned Scientists (UCS – an environmental lobby group) attacked the AAAS board statement on GMO safety and yesterday in a tweet claimed that the AAAS statement was “in opposition” to the National Academy of Sciences, the NRC “etc”.

@mark_lynas On climate AAAS board is in consensus w/ other science groups, on GM they’re in opposition to NAS, NRC, etc ow.ly/hiGgm

— Concerned Scientists (@UCSUSA) January 31, 2013

What is the consensus, and what is your take on the UCS critique?

Professor Fedoroff:

The board statement is pretty careful. It says, as the UCS attack quotes: “Indeed, the science is quite clear: crop improvement by the modern molecular techniques of biotechnology is safe.” You’ll notice that the AAAS Board statement DOESN’T say that “all plants genetically modified by modern molecular techniques are safe,” nor did it say what he [Doug Gurian-Sherman from UCS] claims it does: “a blanket statement that GE crops are “safe” is misleading.”

There is no evidence that modifying plants by molecular techniques causes problems to the plants, people, or nature. In fact, everything we’ve learned says that plant genomes are much less disturbed and altered when genes are introduced by molecular techniques than when changes are made by genetic crosses, or mutations are made by chemicals or radiation or by putting plant tissues into culture, then regenerating the plants.

Whether a human crop plant causes problems depends on the plant, how it is used and in what context and it matters not at all whether if was modified by modern techniques, old techniques or not modified at all. We have created problems everywhere in the world not just by our agriculture, but by moving plants, animals and insects around. Gypsy moths got out of someone’s back yard. Kudzu was introduced into the US from Asia to control soil erosion (which it did).

However, it is important to keep in mind that agricultural crops are much less likely to cause problems simply because they’ve already been modified over millennia to make them reproduce the way we want them to, make big fruits (sometimes seedless and therefore sterile) and grains that stick to the plants. The problems of agriculture are many: from an ecological perspective, there just isn’t anything as destructive as agriculture. But none of them have to do with the techniques used to modify the plants.

Next the writer of the UCS attack says: “We already have one clear example of a harmful engineered gene (though not commercialized).” Well, my guess is he’s referring to the story about the storage protein from Brazil nuts that was going to be transferred to a crop plant. That was caught in precisely the kind of modern testing, using modern knowledge, that we use now. The gene was expressed and the protein tested for allergenicity because it was a likely candidate and sure enough, it was a good allergen. That stopped the experiments, but the urban myth lives on.

Anyway, you get the picture. He insinuates allergenicity isn’t ever addressed and implies that the AAAS statement says it can’t cause problems. In fact, allergenicity is probably the biggest concern. But we actually know a fair amount about allergenicity and a developer of a transgenic crop has to express the protein or proteins he/she wishes to clone in the genes for and show the FDA that that they are not allergenic. There’s a whole complicated protocol for assessing this (I’m sure it could be improved) and crops have gotten a bad rap for naught because a protein failed one of the crudest tests for allergenicity (remember the Starlink fiasco?), even though it didn’t prove allergenic in subsequent testing. And while he’s technically correct that the FDA doesn’t mandate testing, companies cover themselves prospectively by making sure that they do everything the FDA (and the other agencies) require them to do.

And then there’s the proof of the pudding… there is no evidence that any of the proteins that have been introduced in the most widely grown GM crops have caused allergies.

And yet, there are some major allergens in foods, among the best-known are the wheat glutens and the peanut storage proteins. These are “natural.” GM techniques could be used to eliminate these allergens — and would be — if people weren’t so busy obsessing about some future unspecified danger… and creating regulatory blockades that cost tens of millions of dollars to penetrate on the way to market. Peanut allergies kill!

3. In your AAAS Plenary Lecture, you mentioned GM vitamin A-enriched ‘golden rice’ and the fact that it has been held up by unnecessary regulation. What do you think the effect of anti-GMO activism has been on the deployment of ‘golden rice’ (as opposed to, say, issues with technical development) and what effect if any has this had on people in poorer countries who suffer from Vit A deficiency?

Professor Fedoroff:

The simple answer to this is that the continued GM activism against “golden rice,” especially the recent efforts to discredit the trials that were being carried in China, is a humanitarian abomination. As everyone knows by now, vitamin A deficiency is a major problem for people who subsist largely on rice, as it contains none of it. In the early days of its development, Greenpeace ridiculed it because they believed that alleviating the vitamin deficiency would require the consumption of unrealistically large amounts of it. As the beta carotene content was improved over the years, they found other reasons to demonize it. Today one reads that it’s a sinister plot of big biotech companies…

But the truth is that it was developed by individuals who were driven by the desire to help the poorest people of the world, not by the profit motive. The intellectual property issues have all been resolved and the “golden rice” is to be made available to farmers free of charge. So frankly, this will be one of the real success stories for development, if it ever makes it out of regulatory purgatory and becomes acceptable (which itself will take some marketing itself in view of the decades of GM demonization).

4. You also mentioned in the lecture the need to massively increase food production in response to population growth and other factors. What is your response to the often-heard objection that we already have enough food, and all the problems are in distribution and wastage or other social and economic factors?

Professor Fedoroff:

The answer is that it isn’t either/or, it’s all of the above. Yes, today there is enough food if we could just reduce waste and spoilage …. and oh, by the way, solve the poverty problem, so that everyone could buy the food that is available. But it still won’t change the fact that the number of people will continue to grow for some decades and, paradoxically, reducing poverty creates more demand for food of higher nutritional value. As people climb out of poverty, they seek more food and particularly to add more animal protein to their food. This creates an even greater demand for the grain crops we largely feed animals – and which are now increasingly used for producing fuel. The central issue with animal protein is that it simply takes a lot more grain and water – and I mean like 10 times more — to make a pound of hamburger than it takes to make a pound of you if you’re eating the grain yourself.

Much food spoilage is attributable not to people discarding good food, but to insect, fungal and bacterial contaminants, as well as the inability to preserve food long enough to get it to a market, in some places hampered simply by the lack of roads. GM approaches can contribute to the amelioration of the spoilage problem – if the regulatory costs burden could be reduced. Reducing other aspects of spoilage in many less developed nations is about building roads, refrigerated storage facilities, and food processing plants. And finally, changing peoples’ food habits to get them to consume less is a social and sociological problem of significant proportions – we haven’t been especially successful in getting people to eat less of the salt, fat and sugar that gives them heart disease, hypertension and diabetes – but its important to continue and increase these efforts.

5. What developments in plant biotechnology do you think are most promising in terms of improving the sustainability of agriculture in future, particularly given the challenge of climate change?

Professor Fedoroff:

There are all kinds of things that are either in the pipeline or in development that could improve sustainability – and many, many more that could be if we could dismantle the regulatory thicket that is choking it off. Among the most important are modifications that will increase nitrogen use efficiency and the ability to recover phosphorus. There’s just a plethora of modifications that will reduce loss to pest and pathogens, both during field growth and after harvest and during storage. But the real breakthroughs, if they ever come, will be in the efficiency of photosynthesis, which is not terribly efficient. That’s a very tough nut to crack and there aren’t many scientists directly working on it.

6. So I’ve admitted I was wrong to oppose GMOs. What do you think other current and former anti-GM activists should do under today’s circumstances? What lessons should they learn from the past two decades’ of scientific research?

Professor Fedoroff:

Well, obviously I think they should do what you did: stop and learn what the science is about, what we’ve learned over the past almost 4 decades of working with molecular techniques in plants and what this can do to make it possible to grow more food for more people on less land with less water and energy. I would ask that they did what I did when I wrote my book “Mendel in the Kitchen: A Scientist’s View of Genetically Modified Foods.” What I did was to learn as much as I could about, for example, how organic farming developed, whether it’s better for people or the land than what we now call conventionally grown food, about what’s behind and under all of the prevalent scare stories about GM foods, just keep learning and evaluating.

I would also ask that they begin to understand that science is not a set of facts to be harvested from knowledge trees, but a very human process of testing, trying, repeating and only then coming to conclusions. At the heart is a hugely important concept of the “weight” of the evidence. What this means is that any given study can come to very wrong conclusions for a large variety of reasons, including such things that it wasn’t designed well and that the investigator is out to prove something he or she already believes, rather than testing an hypothesis. But if the pile grows and there are 10 studies that come to one conclusion, compared to 1 that comes to the opposite conclusion, and that ratio then grows to 15 to 1 or 50 to 1, then the balance is tipping toward the conclusion come to by the many and not the one.

In the GM field, there have been reports for example, that GM feed makes sickly animal pups, that it poisons rats, or gives them tumors. If you look a bit closer, you often find that these results were leaked to the press (and sometimes never published) or were eventually retracted by the journal in which they were published. But the most important point is, are there 10 or 30 publications that come to similar conclusions, or is the study standing alone against the 10 or 30 that have come to the opposite conclusion? If it keeps on standing alone, then it probably isn’t right…