Pigs and GMO

pigs eating

Pigs that eat genetically modified foods have less inflammation than pigs that eat normal- the opposite of what the news reported

Pigs and GMO
So you read the headlines, or the news article and you see that pigs fed GMO had more stomach problems than pigs that were not fed GMO. Except that isn’t really what the article results show.

The results show that pigs have a lot of stomach problems- regardless of the stuff that is fed to them.
From Table 3 of their study:

Pigs who were fed non GM foods had more erosions, more pin point ulcers than pigs fed GM foods.
(1) Of all ulcers there were equal numbers in both GM fed and non GM fed pigs.
(2) In terms of inflammation – all types – there were 69 in the non GM fed group and 64 in the GM group.
(3) If you look at nil inflammation (meaning zip) – pigs who ate genetically modified foods had much less inflammation than pigs who ate “organic” food.
(4) If you add the “nil inflammation” the numbers are 73 with inflamed stomachs of pigs who ate non genetically modified foods and 72 pigs who ate genetically modified foods had inflamed stomachs.

As a surgeon, who does a lot of stomach surgery – I would say that this study shows really no difference between the two groups of pigs- but when it comes to the severe issues there appear to be a lot more severe issues among the pigs that ate non-genetically modified food than the pigs that ate genetically modified foods.

What does this whole thing prove:
(1) GM and non GM are no different
(2) Pigs have a lot of stomach problems – who knew
(3) Journalists don’t read papers and analyze them, they instead read abstracts where the comments may not equal the results

It is sad that the Journal of Organic Systems – which says it is peer reviewed, but its agenda is not science, its agenda is organic farming and systems. A fine agenda, but when you allow the abstract and conclusion to read the way they did – you simply decrease the value of your journal.

As for you journalists out there – try reading and analyzing the data before reporting it.

5 Myths about GMO & What You Need to Worry About: GMO Part 4



The genetically modified corn uses less pesticides and herbicides

GMO seeds mean you will have more pesticides and herbicides used in the environment.

Just the opposite is true. GMO plants have saved farmers in Illinois, Wisconsin, and Iowa billions of dollars the last two decades in those toxic chemicals.  The GMO plants are designed to use less chemicals than other seeds.

What You Should Be Worried About:
While less herbicide is used (weed killer) the weeds are getting resistant to the herbicides currently and new super weeds are being found. Weeds use natural selection (the first type of genetic engineering) so that those weeds that survive the herbicide grow and reproduce.


The toxins engineered in the plants, like Bt, are deadly to humans and cannot be washed off.

Bt toxin (from the bacteria Bacillus thuringiensis) has been extensively tested and is not toxic to humans or other animals. In fact, Bt, a toxin made by bacteria, is used widely by organic farmers because it is a natural way to control pests. While some have reported animals that have died in fields of Bt cotton or corn, when autopsies of the animals were done other causes were found. In fact, many deaths from farm animals occur in places all the time- This same Bt toxin has been used to decrease mosquito outbreaks in Africa, to decrease malaria and dengue fever. Other strains of the Bt toxin are being examined for activity against leukemia and breast cancer.

What You Should Be Worried About:
In spite of an impressive array of safety, all toxins have some downside. No matter which pesticide, or how safe, there will collateral damage – Monarch butterflies who feed on milkweed, for example, do not do as well when they are near corn that pollinates with Bt toxin.

As much as science searches for a perfect toxin, this certainly is not it. On the bright side new research into pheromones that are scents that keep pests away are being tested.


Monsanto will have a monopoly on seeds and this is bad.

Monsanto does sell the most seeds of any of the major seed makers, but does not have a monopoly.  Since the 1940′s farmers have found purchasing seed was easier than raising their own and proprietary seed makers have become an industry.  Monsanto sells 23% of the GM seeds in the US, currently. There are a number of other seed makers that sell GM seeds, as well as non-GMO seed suppliers. Having a number of suppliers insures a more stable market.

What You Should Be Worried About:
Biodiversity is a major issue, and while genetic engineering represents a rapid way to alter crops in case of a major new pest, blight, drought, it is important to have a large seed repository available. GM seeds or not, biodiversity has been rotated out of our crops and is a major issue moving forward. Biodiversity has been an issue for all crops since humans harvested, and continues to be a major issue to our food supply.


They engineered tomatoes to withstand cold by putting the gene in from an Arctic fish, which is why tomatoes taste bad.

Fresh Fish

Fresh, wild salmon- not farm raised, and no genes of this fish went into a tomato

There is no tomato-fish. While this was an experiment, it never came to market. The reason most tomatoes from the store are mealy is they are picked before they are ripe. They do not ripen as a normal tomato would, and thus have an off taste- especially to those who know what a fresh, garden ripened tomato tastes like.

What You Should Worry About:
Genetically engineered salmon that will be farm raised are coming, and like most farm-raised salmon will have less flavor, less beneficial omega-3 fatty acids, and cause more pollution that the wild salmon. Many fish are over-fished and present a danger to our food supply – farm raised fish are not as sustainable as wild fish.


Animals know better- when given a choice they don’t eat GMO.

The photographs of the corn, and others that are circulating are all doctored photographs- they are fake. Humans have very sophisticated taste buds, much more than a squirrel or birds. The photographs have been put up as “proof” when in fact, all studies contradict them. In addition, why is it that they blame GMO for killing some animals, when there are fields adjacent with non-GMO feed.  They get tripped up in their own arguments.

Fake GMO

The has been widely viewed on the internet – and is a doctored experiment.

What You Should Worry About:
If you are eating at a lot of chain restaurants, or a lot of processed foods, you are probably obese, and should be eating more whole foods, plant based diets.  If you like meat, you should be eating meat from specialty farms where they are raised on grass instead of grain.

For more about GMO:
Read part one of our series where we discuss the basis of GMO.

Part two of our series is about Frankenfoods and labeling.

Part three is about allergies and proteins.

GMO: Part 2 – The Promise, the Fear, Labeling, Frankenfoods

The Fear and Wonder of a Chimera

In ancient times people were told about hybrid animals: the horse that was half human- the torso and head of a man with the body of a horse, the man that had the head of a dog, the horse that had wings. Some have familiar names, like Pan- who had the hind quarter of a goat and horns of a goat but face of a man.

For some these were an abomination, an unholy thing made from cross breeding and to be cursed.  For some they provided a sense of wonder. The Centaur, half horse half human that were great warriors.

Even in the bible, when the “end times” come the description of the feet of the bear and the mouth of the lion and the body of a leopard – a beast and not something to be trifled with. Or Frankenstein, a chimera of people.

The fear of chimeras is throughout all human mythology – but now, those chimeras are no longer a myth – they are real. Humans  can produce a chimera from the DNA of different species, making crops and animals that are modified to produce a chimera.

Are those same fears, same sense of wonder a part of the human collective conscious? Does that explain the debate about genetically modified organisms?



Since the ancient times the fear of chimeras has been a mix of wonder and horror. Now, with DNA technology, are we opening Pandor’s box? Or can we use the technology to save the world

What’s missing is science education, critical thinking, and the ability to talk the same language 

Perhaps it is my background in genetic engineering that makes the idea of genetic engineering interesting, and not scary. The knowledge that humans have manipulated genes in plants for at least 11,000 years gives some perspective. Genetically Modified Organisms (GMO) that are plants are neither the Frankenstein chimera that some suggest, nor are they the magic bullet for the common problems of feeding the world and saving the environment.

They are but one tool and sometimes that tool has  failed. What bothered me greatly as I researched the issue, was that the people who were anti-GMO did not even speak the same language as those who were proponents of GMO. The logical fallacies in arguments were on both sides: appeal to antiquity, appeal to authority, and ad hominem being the most common. One fact was alarmingly clear: people will say anything, put up any photograph, repeat falsehoods because they think their concern about GMO are valid.

This does not advance a rational discussion, this does not help advance the common quest we all would seek to find a safe way to feed the planet.  It also pointed out that critical thinking is not taught, and science education is lacking. There are rational concerns about some GMO, but those discussions become lost when histrionics replaces a sense of history, when the discussion is not about science but about fear. On the other side, the proponents of GMO, are often dismissive – partly because they lump those who express legitimate concern for GMO with those who are clearly irrational , and partly because they become forced into a position to support science.

Thirty Years of Molecular Engineering Plants

In 1983 a gene, made from DNA not belonging to the plant, was transferred into a plant and this technical feat and outcome reported in the journal Nature.  But genetic modification of  plants by humans has been going on for thousands of years. While at times we will specifically use “molecular engineering” for the modern technology of  modifying existing DNA or inserting new DNA into plants, for most we will use genetically modified (GM) crops to mean those crops which have specifically had their DNA modified by molecular technology. Molecular engineering of plants started 30 years ago, and 35 years since we first showed how the DNA coding for a protein from one species (a chicken) could be put it into the DNA of a virus (Herpes).  That use of a virus to host a DNA led to the idea that a plant virus could be used to insert DNA into a plant. DNA codes for all the proteins of the plant, much like humans. The techniques used then are now considered as outdated as using a floppy disc – and in fact, the ability to molecular engineer DNA can be done in a garage.

When we made our chimera (Herpes -Chicken) the concerns about molecular engineering were not yet articulated.  At that time it was a breakthrough to prove we could move a gene from one bit of DNA to another, and have that new organism make the chicken protein. Prior to that it was theoretically possible, but never proven. Once proven, did we open Pandora’s box or did we find the stairs to heaven?

Would you inject it?

We worry about our foods, a lot. So imagine injecting something like this directly into your body: in addition to an ingredient that has been extracted from a genetically modified organism  it is labeled like this-


insulin partial


People inject this everyday? Did you know that people not only inject this everyday but it keeps them alive? It is called insulin.  So when worried about the food supply, do not forget that GMO also applies to bacteria and yeast that produce proteins that some need daily to keep alive and healthy.

Would you ingest it- and should we Label it

Why not? The insulin above is clearly labeled, it says what it is- where it is from, and what else is in it. The question is- how do you label corn – because corn is a new plant, it wasn’t even around a few thousand years ago. Although most who wish food to be labeled intend those foods that contain proteins from another species. The insulin which the vast majority of Americans take, come from DNA from humans, but grown in yeast or bacteria.

The anti-label side states that most scientists, and the FDA find the food is safe, so why add an additional label to the ingredient. The counter argument: should not people decide for themselves if they wish to have it.  In a way this is an esoteric argument: I have a hard time getting my patients to read food labels- and most Americans do not read labels. But there is nothing wrong with a label, there is nothing wrong with letting people decide what they wish to consume.

Most of the corn and soy grown in the US are genetically modified. There has been no immediate ill effect, and yet, some would argue that trans-fats, once considered to be good fat, were not discovered to have an ill effect until years later.

The anti-label says that some people would shun those foods, wanting non GMO foods. The pro-label says, yes, that is the idea.

The fear of industry that they would have to change or educate the public is paternalistic, and reminds me of the argument at the beginning of the enlightenment that churches didn’t want their flock to learn to read lest they question authority.

What doesn’t help is this: we have lost science journalism. Finding a journalist who can look critically at a paper and present the information in a detached way is gone. Most journalists now, even from The New York Times, are more entertainment-style journalists – flashing a headline, quick quotes from a pool of scientists or physicians, and off with a story. But GMO are too important to leave to such journalists, GMOs are here to stay, but need to have a place where rational discussion can happen from those who are concerned.


Proteins and Plants

DNA is the programing code for proteins that are made by an organism. Even more than just a code for the proteins, it is the program for how the proteins are produced, when they are produced, and how much is produced. The code can  keep a given protein from being made under certain circumstances.  If you take the DNA that codes for a protein  and put it into corn you will have corn that produces that protein (sometimes).  Not all proteins that are in one species can be produced by another species even if we put the proper DNA sequence in the host.

For GM crops, most of the proteins that are manipulated with DNA are either the plants own proteins, or proteins from species that interact with that plant.  Bt cotton, for example, is a cotton plant who has had bacterial DNA  that codes for a protein that discourages bollworms and thus decreases the need for pesticides. This Bt DNA has also been placed in corn, and it was estimated to save 3.2 billion dollars  to farmers in Illinois, Wisconsin, and Minnesota over the past 14 years as well as a savings to non-Bt corn growers of more than 2.4 billion over 14 years – in pesticide costs.  The farmers were able to have higher yields of the corn, reducing loss from insect damage, reducing pesticides (mycotoxins), and providing a simpler and less expensive and environmentally friendly pest management option.

Lovers of organic farming will tell you that soil is a viable, living thing- with many different animals contributing to the balance that allows plants to grow. The most common are organisms called nematodes. A study out of China showed that planting the GM cotton did not affect soil nematodes. Compare that with the non Bt fields, where increased use of pesticides has wiped out a number of the organisms rendering the soil sterile.

On the horizon are crops that produce pheromones that pests interpret as “danger” signals, meaning less pesticides or even the promise of no pesticides would be needed.

Genetic Engineering: Farmers are more concerned with the environment than most know

City folk seem to think they are the only ones who know about industrial and organic farming. Many city folk assume, sometimes correctly, that modern farming has sterilized the land upon which we grow crops and make the assumption that GMO is another step in the destruction of our planet. Yet, if they were to go to farm conferences the most well-attended presentations are about environmental issues.

No one is closer to the land than a farmer, no one cares more about their land than a farmer – including those who own the large agri-business.  It is not the goal of agri-business to destroy the land they get their crops from. The goal of farming production, is to use less fertilizer, less herbicides, less pesticides, and less water. The hard way to do genetic engineering is what the Mayans did.  But over a few thousand years they took one plant, and made it into another species – one that wasn’t recognized until 10,000 years later.

The Promise of Molecular Engineering plants:  The promise of molecular engineering is based upon what Genetic engineering already showed: the ability to make crops that (a) grow faster (b) resistent to pests (c) resistant to weeds. We would add that the new goal of molecular engineered plants would be environmentally friendly, at the least, and helpful to the environment at the most.  The ability of plants to convert carbon dioxide to oxygen may be one of the major ways to diminish green-house gases.

In GMO farms there are less pesticides and less herbicides used. That doesn’t mean it will always be this way. What GMO has done is improve the yields of crops, it has decreased the use of some toxic chemicals on the land, it has provided a mechanism to improve nutrition, and decreased the use of water. But that can change.

Fake GMO

The has been widely viewed on the internet – and is a doctored experiment.

In an effort to find the truth about GMO – and avoid the hyperbole on both sides, I did discover some rather disturbing myths out there. One is a photograph that shows a picture of two corn cobs, one eaten, the other not. One labeled GMO corn, the other not – it is a doctored photograph.  To think a squirrel would have more taste or better taste than a human is not only biologically incorrect, it is laughable. The person who put this up is a well known anti-GMO activist. This does nothing to further discussion, but is propaganda to increase fear.

In a rational discussion about the pros and cons of GMO we need a basis of discussion and not myths

Here are some things that are on the internet that are myths

- the tomato fish: They have a tomato which has a gene inserted in it from arctic fish so that the tomato will survive cold weather. This is not true. The cartoon 0f a chimera fish/tomato was a rallying point for some anti-GMO sentiment, but it turns out that such a product is not to be found on any market shelf. I understand one of the main issues was vegetarians who were concerned that having a protein from an animal in a plant would violate their vegetarianism (ok, that one made me scratch my head also). It was an interesting idea, and no one has any idea how far these experiments went, but biology would tell you that a frost resistant fish probably isn’t going to be helping a tomato. When the company who was working on the project was approached they noted that the experiment was a dismal failure. Then again- think about it: a fish has a heart and blood vessels and is pumping things – a tomato, well, doesn’t. Still the idea of transferring proteins from one species to another, much as we did 35 years ago, raises concerns. The problem is that there is too much hyperbole in the debate and the discussion.

German Cows Die after Eating GM modified Corn: It is true that Syngenta(the supplier of GM corn) reimbursed the farmers for the loss of cows, and that the cows did eat the corn that had been genetically modified.  The investigation of the cow deaths concluded that the GM corn was not the cause of death. In addition, there were extensive feeding studies of that GM corn (Bt 176) which were published in peer review journals and there was no adverse effect. Further, that corn had been planted for a number of years without adverse effect in those fields.  Turns out the cows probably died of botulism.

Did rats get tumors when eating GMO corn?: Rats developed tumors when eating GMO corn – not really. This was a paper that was published- and it had a lot of flaws: (a) These types of rats all develop tumors when they get old (b) severe statistical issues, with a small control group (c) No basic statistical significance (d) No dose response curve. The rats were fed unlimited amount of corn – if you feed this type of rat unlimited food they develop cancer.  Bad study, highly repeated in the internet – not repeated by anyone. Here is a response printed in full to that article: Seralini et al. (2012) claim to have found evidence for the long term toxicity of roundup-tolerant genetically modified maize (GMM). Using one-tailed Fishers exact test we show that there is no statistically significant increase in mortality rates or the number of tumors in rats fed GMM compared to control groups in the original data. Seralini et al. state that “In females, all treated groups died 2–3 times more than controls”. As follows from the figures presented: 2 female rats out of 10 died before the mean survival time in the control group, compared to 29 out of 60 in the six GMM fed groups. This difference is not statistically significant (P = 0.09). Note that this P-value requires a further correction for multiple comparisons due to two groups of rats (of different sexes) being independently analyzed. Among males 3 rats out of 10 died prematurely in the control group, compared to 19 out of 60 rats in the six GMM fed groups. This difference is statistically not significant (P = 0.615). Ironically if we forget about the importance of statistical significance and present the data in a manner used by Seralini et al., we could say that “In males, groups with 22% and 33% GMM in their diet died 3 times less than controls”, however this was not reported. This difference is also statistically not significant (P = 0.291 for each comparison). Seralini et al. state that “In treated males, liver congestions and necrosis were 2.5–5.5 times higher” and that “Females developed large mammary tumors almost always more often than and before controls”. Two male rats out of 10 had liver pathologies in the control group, compared to 30 out of 60 GMM fed male rats. Five female rats out of 10 developed mammary tumors in the control group, compared to 44 out of 60 GMM fed female rats. These differences are not statistically significant (P = 0.076 and P = 0.133). Note that this analysis should be done with care: over 30 different organs were analyzed in this study, but data on only a few was presented, giving rise to the statistical problem of multiple comparisons that was not addressed in the article. However, even despite this problem, all reported differences between the number of rats with specific organ pathologies in control and GMM fed rats are not statistically significant. It is also worth noting that tumors are frequent in Sprague–Dawley Rats: a spontaneous tumor incidence of 45% was previously recorded during a 1.5 year period (Prejean et al., 1973). The images of GMM fed rats with large tumors presented by Seralini et al. are misleading as they imply that such tumors do not normally occur or occur less frequently in untreated rats. Such tumors may occur in rats that are not fed GMM and Seralini et al. provide no statistical evidence that the incidence of tumors in general or any specific kind of tumor is increased in GMM fed rats. The random nature of the observed differences between control and GMM fed rats in the study is consistent with the lack of dose-dependent relationships between the amount of GMM in the diet and the supposed toxic effects of GMM. A news article published in Nature stated that “The controversy over the findings is likely to be settled only after detailed analysis of the paper and its data, and replication of the experiments” (Butler, 2012). Analysis of the data suggests that no statistically significant findings of GMM toxicity were presented in the first place.

Did sheep die from eating cotton with Bt? In a word, no. In almost every anti-GMO site I visited this was repeated over and over again, in spite of the simple evidence against it. This involved a group of sheep who died after grazing on a field of cotton. The accusation was that the sheep died from some unexplained poison – and that part is true. Sheep have been dying from toxins in cotton fields long before Bt cotton, and with the same lesions described by the anti-GMO groups.  In all cases the veterinarians describe that the sheep died of a toxin, probably pesticides used. Veterinarians  could not rule out nitrate or gossypol (a natural toxic ingredient of cotton plants) as toxic agents.  When Bt was fed to laboratory animals there were no deaths. Less pesticides are used on Bt Cotton modified plants, the total use of pesticides in the 10 million farmers who use Bt cotton has gone down.



I am not, nor ever have received funding support from Monsanto, or any corporation making or considering GMO. The funding received for the original research done with molecular engineering came from a grant from the National  Institutes of Health, and not associated with any industry.  Nor have I been paid any stipend, nor received any accommodation from such industries. Nor am I seeking such.


Allergies and GMO – the real story

GMO and the Third World



(1) Areawide Suppression of European Corn Borer with Bt Maize Reaps Savings to Non-Bt Maize Growers W. D. Hutchison, E. C. Burkness, P. D. Mitchell, R. D. Moon, T. W. Leslie, S. J. Fleischer, M. Abrahamson, K. L. Hamilton, K. L. Steffey, M. E. Gray, R. L. Hellmich, L. V. Kaster, T. E. Hunt, R. J. Wright, K. Pecinovsky, T. L. Rabaey, B. R. Flood, E. S. Raun Science 8 October 2010: vol. 330 no. 6001 pp. 222-225 PMID: 20929774

(2) A 2-year field study shows little evidence that the long-term planting of transgenic insect-resistant cotton affects the community structure of soil nematodes. Li X, Liu B. PLoS One. 2013 Apr 16;8(4):e61670. doi: 10.1371/journal.pone.0061670. Print 2013. PMID: 23613899

(3)Beever D and Kemp C (2000). Safety issues associated with the DNA in animal feed derived from genetically modified crops. A review of scientific and regulatory procedures. Nutritional Abstract Reviews Series B: Livestock Feeds and Feeding 70:175–182.

(4)Flachowsky G, Chesson A, and Aulrich K (2005). Animal nutritional with feeds from genetically modified plants. Archives of Animal Nutrition 59, 1–40.

(5)Flachowsky G, Aulrich K, Bohme H, and Halle I (2007). Studies on feeds from genetically modified plants (GMP) – Contributions to nutritional and safety assessment. Animal Feed Science and Technology. 133: 2-30.

(6)Goldstein DA, Tinland B, Gilbertson LA, Staub JM, Bannon GA, Goodman, RE, McCoy, RL, Silvanovich A (2005). Human safety and genetically modified plants: a review of antibiotic resistance markers and future transformation selection technologies. Journal of Applied Microbiology 99:7–23.

GMO : They’re Not What You’ve Been Told

GMO – Part 1

This is a series about genetically modified organisms. We anticipate there will be three parts. It will be comprehensive, but if you are truly interested in this field, we hope you enjoy this.

Genetically Modified Organisms are bad. Monsanto is evil. These crops are killing us. 

Well, not really. This is not a simple topic – that is, it is not as simple as “this is bad and we shouldn’t do it” or “its not natural, so it must be bad.”  Nor is it “corporate evil.”

My background about this topic:

I did genetic engineering as a graduate student  at The University of Chicago.  What we did with  genetic engineering, people have been doing for thousands of years, the difference is we did it in a laboratory. You will see in the first part of this series how the majority of genetic engineering was done thousands of years before the field of genetics was understood by Europeans. My name is on a landmark paper where the first eukaryotic gene was inserted into a Herpes Simplex Virus and regulated like by the genetic regulation of the gene it replaced – obscure, but an important and first paper about the topic.

I left most bench research for a while to become a physician (I liked people better than petri dishes). As a physician who spends most of his time researching food, talking to patients about food – the politics of food fascinates me. We have shown that the single most important variable with success for surgery patients who have had weight loss surgery, is their willingness to cook. Patients who learn to cook, to appreciate food, at five years post surgery do much better than those who fall back into their habits.

Genetic Engineering was Started by Native Americans

Corn is genetically engineered, there was no corn 10,000 years ago.  Corn was genetically engineered  by Native Americans,  not done in a lab – it was done by methods that Europeans would discover, and call genetics. Corn had been already engineered thousands of years before the “father” of genetics, Gregor Mendell was born, and the first Europeans were given this food from Columbus onward.

Corn progression

Thousands of years of selective breeding changed how corn looks. Photo from Robert S Peabody Museum of Archeology, Andover MASS – all rights reserved

It all began with a grass  called Teosinte (pronounced “tA-O-’sin-tE”).  Teosinte does not look like corn today, but the DNA shows they are alike, and it was this grass that Native Americans 10,000 years ago began to engineer. In fact it wasn’t until a few years, 2005,  ago that modern molecular geneticists discovered that this grass, Teosinte, was the father of corn.  For years people who study plants, botanists, assumed the evolutionary predecessor to had long since died out. And while Teosinte is widely spread throughout central America, it was not even considered in the same family as corn.

What modern molecular biology has done to corn is nothing compared to what the ancient Native Americans did.

The original ear of Teosinte is 2-3 inches long with 5-12 kernels. The kernels were hard, and most human teeth would break trying to eat them. Teosinte is inedible for people. Contrast Teosinte with modern corn with a cob that is 12 inches long, with over 500 kernels.  The coating on the kernel was selectively bred from the rock-hard protecting seed to, now, where corn has an easily chewable,  paper thin, but still indigestible membrane.  This was breeding at its finest.

Ten thousand years ago there was not a plant that anyone would recognize as corn. In fact, there was no corn. By 4500 years ago corn was throughout all the Americas, with carbon dating of kernels in Arizona from over 3000 years ago, Canada 700 years ago.. It allowed the Mayan people to go from a people who foraged, to a people who could stay and cultivate.

Teosinte is a hard, inedible kernel – this grass and corn share the same DNA, with some simple modifications one becomes the other

You can see from the photos how as time went on corn changed: both Teosinte and corn have the same number of chromosomes, they have the same genes that code for the same proteins. Teosinte and corn can be bred, because they are so close genetically.  The difference between the grass, Teosinte, and modern corn is about five genes.  Corn didn’t “evolve” corn was “genetically” engineered by early Native Americans.

It all started in an area that we know today as El Salvador, where the Mayans discovered the plant in the mountains of Chalatenango. Recently a damn revealed a village in the area, which was one of the original four Lake Island villages of the Mayans, and on this land one can see the range of corn from the grass to the modern corn.  If you hike there  you can see places where the Mayans would grow special crops, where they would harvest the Teosinte with the kernels they could eat, and over time they would breed it and cross breed it until they had an agricultural system that was based on this plant.

The first genetic engineers cultivated a grass called Teosinte – in the region now known as El Salvador. Credit: Library of Congress, LC-USZ62-46945

So sacred was corn, that they called it the “grain of the gods.” To this day the people in Santa Ana,  in western El Salvador, still plant little plots of primitive corn that they called something like “ulupiche”. This is not to eat but simply to please the ancestors. It is from these Mayans that corn was selectively bred, or genetically engineered for better taste, different colors, ability to withstand pests.

Thousands of years later in Europe and the United States: 

For over 5000 years there was no change in corn, until the Europeans discovered the field of genetics, and began to reapply what the ancient Mayans had done.  About 8000 years after the Mayans engineered Teosinte to corn, in 1865, Gregor Mendel presented a paper about his experiments with peas – and ultimately developed the early laws of genetics. Genetics became a new biologic field, and the first major publications about corn were in 1908 when a University of Chicago graduate, George  Harrison Shull,  began researching genetics using corn while at Cold Spring Harbor laboratory. His interest in maize was taking purebred lines and crossing them, and discovered they were more vigorous than the original strains. This increased vigor, and ability to increase yield meant a lot to farmers growing corn. As a result several companies developed corn and yearly would sell the seed to farmers. Some strains were developed and distributed to farmers without cost, such as The University of Wisconsin.

The hybrid corn was uniform, strong, and rapidly began to replace the open-field pollinated corn. This uniformity allowed for mechanized harvesting, and increased yield from 20-30 bushels per acre to over 120 by the year 2000. Currently, corn growers have changed emphasis from increased production to environmentally sound productions.

In early, pre-molecular biology, days, corn was used to study genetics. In those days biologists, like Shull, would breed corn to examine the determine genetics of the corn. The genes that were commonly manipulated either by geneticists, included the genes responsible for the color of corn, it can be yellow, white, blue, orange. In addition genes responsible for its resistance to pests, genes responsible for the taste of the corn (sweet corn is different than popcorn, which are different than corn grown for cattle, or that grown for fish).

More recently, using the techniques of modern molecular biology, the DNA has been mapped for the corn, and certain proteins have been allowed to be expressed more than others. Working in the laboratory, where the entire DNA sequence of maize is available, the genes can be manipulated to increase various proteins. How this is done, and whether this is good is for the next blog

All corn has been genetically engineered

There is no corn on this earth that is not genetically modified. Corn was the example we used here, it can also be said for wheat, tomatoes, papaya, and a few other crops. All have been genetically modified – and if one begins to label GMO foods, then all those crops, and more, will need to have a label.

Here the debate gets ugly:

You may have seen photos on the internet: people show two ears of corn, one, they call GMO the other is “organic” and one is eaten by squirrels and the other is not. None of those photos has been truthful. Or the little girl who as a science project showed how bees avoided some genetic engineered produce. These are sad anecdotes from people who have an agenda. We don’t need anecdotes in this debate, we need truth. The truth is simple: all corn has been engineered for years. We will answer some of the claims which are valid, and some are irrational.

(a) Should they be labelled – no reason not to be. This may be a problem, because we have to decide at what point do we label – which crops, and what. Since all corn is new from humans harvesting, it would all have to be labelled.

(b) It is bad for diversity. All crops today are uniform, and yes, they represent a non-biodiverse species. This has led to problems – the Irish famine, for example- but that wasn’t because of molecular genetic manipulation, that was how potato crops are.  All corn, all wheat, all soy- when you look you will see single hybrid lines. Think of Teosinte – it had far more biodiversity than corn. The wild grass could adapt to different places, but in choosing the genes to express, corn now has a wider range than Teosinte ever could imagine. Some might say that this grass has done a good job of getting humans to spread it around the globe.

(c) It can lead to greater famine and weeds. The constant threat since humans began to cultivate plants was the threat of famine, or pests, or weeds that would wipe out crops. GMO does not change this. Having a modification of a plant can help it.

(d) Animals avoid GMO food. Most of the photographs have been faked. But remember, most GMO foods you will avoid also. You won’t be eating the vast majority of corn because it is meant for animal feed. If you tried to eat that you would find it unpleasant. You would eat sweet corn, but a cow would avoid that.

(e) The genes can get into and affect humans. This is one of those things that is “possible” but not probable. Any bit of DNA anywhere in the world can infect humans – but it is highly unlikely. The GMO crops do not change that simple fact. Any DNA from any organism can get into our DNA- it simply doesn’t happen that ofen.

(f) GMO leads to increased use of herbicides and pesticides that are bad for the environment.  Turns out that most agriculture isn’t that great for the environment. A large farming system depends on chemicals to fertilize it, to replenish nitrogen and phosphorus, and to get rid of weeds as well as any molds, fungus, insects, or parasites that will consume the harvest. This is not new – this is the state of agriculture. The good news is that they are starting to work on growing things differently. More about this later.  The idea behind many of the crops is to have those that are resistent not to the pesticides and herbicides, but to the pests and the weeds themselves.


Someone is bound to say that there is a difference between what we do in the laboratory and what the Mayans did to Teosinte. There isn’t. Not one bit. There might even be those among you who wear tin hats who would say – an advanced civilization did genetic engineering – except we have the ruins to show the Mayans did in fact do this. It is exactly the same. We are just more efficient at it.

Industry affiliations:

I have never received a grant, money, dinner, or stipend of any kind from any agricultural company (Monsanto, Dupont, etc). No research I have been involved with, no writing supported by, no television advertisement paid for by any agri-business ever.


A lovely view of the archeology of the area see this: http://inclusivebusiness.typepad.com/indigenous_elsalvador/corn-and-teosinte/

The NSF announcement of Teosinte as corn:  http://www.nsf.gov/news/news_summ.jsp?cntn_id=104207

90 years ago: the beginning of hybrid maize. Crow JF. Genetics. 1998 Mar;148(3):923-8.  PMID: 9539413