Anti-GMO myth busted—We’re not losing plant genetic diversity after all

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It’s been a familiar meme for some time — anti-GMO activists blaming genetically engineered crops for a drastic loss of diversity. The magazine National Geographic even got into the game, publishing a graphic showing an apparently catastrophic 97 per cent loss of diversity in crops between 1903 and today. The graphic, the esteemed magazine claimed, showed how “As we’ve come to depend on a handful of commercial varieties of fruits and vegetables, thousands of heirloom varieties have disappeared.”food-variety-tree-754

Anti-GMO sites like Mike Adams’ Natural News quoted other similarly minded activists who have no expertise in science or genetics such as risk expert Nassim Taleb, in warning that genetic engineering would lead to nothing less than the end of the world. Why? “Because the rise of GMOs is nearly synonymous with the collapse of genetic diversity in seeds and food crops.”

Activist and philosopher Vandana Shiva regularly claims that GMOs are “a death knell to biodiversity:”

Even the UN’s Food and Agriculture Organization (FAO) decried a 75 percent reduction in crop diversity, and called for a push to store and use wild crop relatives.

While the FAO’s call is not a bad idea, has there actually been a diversity decline? The truth is, these claims are flat wrong. We have not lost much diversity at all over the past 100 years. How did so many people get this so wrong?

Comparing the wrong apples and oranges

These claims of diversity loss claims are almost entirely based on a study completed in 1983 by the Rural Advancement Foundation International (RAFI), which was never published and never went through peer review. However, it was publicized heavily by the FAO among other organizations and authors. The study compared a 1903 US Department of Agriculture survey of seed catalogues. The RAFI study claimed that only 3 percent of the seed varieties available in 1903 were still available 80 years later. Garden bean varieties, for example, fell from 185 varieties in 1903 to 32 in 1983. Lettuce varieties fell from 107 to 36, and tomato varieties plummeted from 408 to 79. Thus, the RAFI study concluded, only 3 percent of what was available in 1903 remained today.

There’s a big problem with this report. By comparing seed catalogues in 2004 with the 1903 seed catalogues, two University of Georgia researchers found that, for 48 vegetables, farmers in 2004 instead had just as many varieties to choose from as did farmers in 1903. In fact, varieties of several crops had increased drastically. Paul Heald and Susannah Chapman reported 7,100 varieties of crops in existence in 2004, compared to 7,262 varieties of crops in 1903. For garden beans, the number of varieties rose from 185 to 771, while lettuce varieties rose from 107 to 520, and tomatoes skyrocketed, from 408 to 1,536.

What accounted for this? The RAFI researchers simply looked at whether the varieties for sale in 1903 were still for sale in 1983. They did not account for the fact that crop variety has increased in many ways not reflected in the data they cited: preservation efforts including intensive seed banking, imported varieties of seeds to the United States, and innovators who have bred new varieties (including synthetic wheats, new hybrids, and yes, genetically modified organisms).

Another problem that explained the understatement of diversity numbers were the nature of varieties themselves. Namely, many varieties noted in the early 1900s did not represent different species; rather they were just the same rose (or tomato) by another name. The original author of the 1903 USDA study, William Tracy, made that clear. He conducted his research, he said, because “variety names of vegetables in this country are being greatly multiplied every year by the renaming of old varieties.” For example, while Tracy found 578 named varieties of garden beans, only 185 of those were truly distinct. So wiping out nearly 400 varieties represented zero loss of diversity; it was just a book clean up.

History of fake varieties

By the early 20th century, seed-saving was starting to lose its dominance to market production. By the 1930s, more than 300 companies offered seeds through 35 million catalogues. 60 percent of vegetable seeds were commercial, instead of home-saved. About 7,000 varieties of apples arose between 1804 and 1904, and 1,362 varieties of strawberries were described in 1925. But how many of these were actually varieties?

Many varieties were the same plant, or an outright fake, with the lister trying to suggest it was a new variety. In California, nurseries were found to be flooding markets with varieties that, well, weren’t. Grafting on to rootstock meant being able to clone an unlimited number of identical plants with easily identifiable characteristics (color, size, shape, growing ease, flavor). But unscrupulous operators also could sell exact copies of another variety, or a complete forgery. “Every man his own nurseryman” started to mean that everybody could have his own variety, whether or not it was truly a new varietal. This ongoing scam was one of the reasons for the 1930 Plant Patent Act, which initially protected only non-sexually reproducing plants, such as those sold by nurseries.

Waves of diversity

Crop diversity may not be waning, but it has been variable, at least over the past century. In a meta analysis published in 2010, researchers from Wageningen University in The Netherlands concluded that no substantial reduction in diversity of crop varieties occurred in the 20th century. In other words, National Geographic, et al. did not do their homework (and cranks and quacks like Taleb and Adams couldn’t care less about the truth; they’re just propaganda pushers). The Dutch scientists did, however, see a dip in diversity in the 1960s in wheat and other crops, but a subsequent increase in diversity in the 1980s through the 1990s. This group’s study overlapped somewhat with the University of Georgia study and ascribed the improvement to gene banks, better communications among breeders and easier seed exchange.

Ironically, many anti-GMO activists tout heirlooms and other so-called “naturally grown” varieties of seeds and plants as alternatives to modern, large-scale agriculture. But heirloom isn’t a precise, scientific term—it can mean nearly anything to anybody, just as the name of a tomato, potato or lettuce variety meant nearly nothing 100 years ago. As the advances of the 1960s and 1970s Green Revolution showed, focusing on the past is no way to prepare for feeding future mouths.

Andrew Porterfield is a writer, editor and communications consultant for academic institutions, companies and non-profits in the life sciences. He is based in Camarillo, California. Follow @AMPorterfield on Twitter.

  • RobertWager

    Another myth bites the dust.

  • Jason

    I have no way to prove this, but I wold suspect that corn & soy biodiversity is greater now than prior to genetic modification. Up until the 90s or 2000s, it was common practice for seed genetic suppliers to sell a specific hybrid or variety to many different seed companies. Each seed company would grow & harvest that seed stock and give it a name unique to their company. Farmers could buy a bag of hybrid corn from 3 different companies and unknown to them, it would be the exact same hybrid.

    We can’t do that anymore, which has led many companies to purposely choose to carry products that are different than what competitors carry. Carrying different products means that more diverse products are likely used.

    • Matthew Dillon

      What you suspect is not at all accurate. Monsanto uses 2-3 male inbred corn lines for all of their hybrid corn seed. DuPont-Pioneer might have 4-5. The spread of Goss’s Wiltin the US is due to a single male inbred that Monsanto uses in production that is susceptible to the disease. Unfortunately, while we have the tools (sequencing is cheap now) to measure genetic diversity and do allelic comparisons of commercial hybrids, pure lines, and parent lines to get baseline data – we are unable to do so due patent restrictions. I serve on the USDA National Genetic Resource Advisory Council, and our council has made strong recommendations that we need baseline data on diversity in the field but we can’t get in because of IP. The DuPont scientist on the council is the loudest and strongest advocate of the need for baseline data and calling out the risk of vulnerability. The National Geo graph certainly misrepresents diversity (it is not by name alone) but the GA study this author represents is no better. To truly measure diversity in the field we must use genomic tools…..we have them…but can’t use them…because….Monsanto IP lawyers. I directly asked Robert Fraley to work with public scientists on this and he has yet to respond with a reason for NOT doing it. The data would be totally protected and not reveal confidential business information.

      • Jason

        Well, I cant speak to all of your claims but I can speak to the male inbred lines that Monsanto uses. We (smallish regional seed company) source genetics from Monsanto (among othrrs). Their rep sits down with us and discusses the hybrid crosses they’re proposing that we carry in our lineup. I see the male x female crosses and while I don’t know how many Monsanto uses, I can assure you that it is many, many more than you claim. In our small maturity set, we use far more than 3 males from Monsanto. In addition, we source genetics from other providers too.

        • Chad

          Numerous studies have shown that the genetic base of most varieties of commodity crops are based on a very narrow foundation…especially considering the vast genetic variability amongst landraces.

          • Jason

            Narrow by what definition? I’m speaking of the current state compared to the state 20 years ago. I would certainly expect that commodity crops would have a more narrow genetic range that wild species but so what?

          • Chad

            Narrow in comparison to the diversity within that species. A landrace is a domesticated regional ecotype. For instance, in Asia, there are hundreds of soybean landraces. However, pretty much all the varieties in the US descend from a dozen or so of those landraces. That means that the US soybean varieties ( of which there are many ) represent only a small fraction of the actual genetic diversity within soybeans.

            You may have access to quite a few corn varieties, but how diverse are they genetically? How much of the genetic diversity within corn do they represent? I am willing to bet that its actually fairly small.

          • Jason

            I am sure it is small in comparison to what is planted worldwide. However what is planted worldwide will mostly, not be suitable for production in my narrow geography. So, I’m not sure that’s really a valid comparison. Again… My point was that I am speculating it has improved in the past 20 years due to laws regulating how a hybrid goes to market.

          • Chad

            How so? Improving the diversity would require increasing the genetic base from which it is being bred from.

            Also, while many of those other landraces may not be suitable to your environment, they possess a wider range of diversity in other traits that would be valuable…in particular when it comes to disease resistance. Nearly all US soybeans are dependent upon a single locus for soybean cyst nematode resistance. That posses a very real risk to soybeans in the US, just as world-wide, most wheat relies on one or tow loci for rust resistance.

          • Jason

            Of course they may have other traits that are of value. Your claim is that the current breeding stock can be traced back to 17 varieties. So? It doesn’t mean that only 17 varieties are used. What about all the other varieties that have been crossed with and back crossed from in order to introduce new traits? If your goal is to trace back the evolutionary path of soybeans as far as you can then by definition you are selecting for a smaller & smaller set with each generation you go back.

            But how is that bad? Clearly this had led to a pretty steady increase in production. Yes, more diversity leads to less risk of crop failure. But if that lower risk comes at the expense of lower production then isn’t THAT the bigger risk?

          • Chad

            How many varieties have they actually been outcrossed too? Outcrossing to unimproved landraces followed by backcrossing to achieve that introgression takes a long time. Do you have any idea how often it has actually been done?

            Secondly, its worrisome from the perspective that over-reliance on a rather narrow genetic base also means heavy reliance on a small set of genes for disease resistance. If we know anything about disease resistance, its that over-reliance on one mechanism puts the entire system at risk when resistance develops. Broadening that base, minimizes that risk.

            We also don’t know what traits will be valuable moving forward. What has been bred for one climate, may not be relevant 10 or 20 years from now. Climate change or some other factor could necessitate a new set of traits. If these other varieties, landraces are lost (as is happening) then that reduces the genetic pool one can draw from in a breeding program.

          • Jason

            You act as though because a trait is not used in production, it’s lost for all time. What makes you believe the genetics are not available? Every inbred we access is an example of an out cross/back cross. There are dozens we use in a given year, let alone over the 20 years I’ve been in Ag.

            “If we know anything about disease resistance, its that over-reliance on one mechanism puts the entire system at risk when resistance develops. Broadening that base, minimizes that risk.”

            But you’re speaking about 1 risk. There is no magic bullet and lowering one risk often comes at the increase of another. So? There are many, many risks that need be balanced, including the risk of underproducing. It’s like saying that we shouldn’t produce skyscrapers because it puts an over reliance on one building. The goal isn’t to produce with the least risk. It’s to produce the most with as little risk as you can tolerate.

          • Chad

            When landraces are lost because of replacement by improved varieties with a narrower genetic basis, then you will have a loss of genetic diversity overall.

            This is EXACTLY why there is such a concerted effort to catalog, maintain, and preserve that diversity through seed banks.

            Those “dozens” of inbreds are based on a very narrow range of genetic diversity. In the US, they pretty much all pretty much cluster together into one of three groups and share high identity to either B73, MO17/Oh43, or PH207…even these three clusters share more in common with each other than not. http://www.genomebiology.com/2013/14/6/R55

            What that means is that all those “dozens” of inbreds you work with capture a very very tiny fraction of the diversity that exists amongst the various maize landraces. Even with outcrossing, this has not greatly expanded the diversity of the lines currently used. Meanwhile, many of those landraces, are going extinct. The loss of unimproved landraces means a loss of genetic diversity in maize and reduction in what breeders potentially have available to them. I say potentially, because typically they are not working with the full range of diversity, but that rather narrow set I just described.

            I am talking about a major risk. You also don’t know what variation may exist that could also improve yield. All that potential is lost when landraces which developed over hundreds/thousands of years and so have greater diversity are lost.

          • Jason

            “Even with outcrossing, this has not greatly expanded the diversity of the lines currently used. “
            According to what evidence?

            “Meanwhile, many of those landraces, are going extinct.”
            According to what evidence? Aren’t tens of thousands being catalogued?

            “I am talking about a major risk.”
            According to what evidence?

          • Gene

            thanks for that link, i have been looking for that information for a while. i think it went over jason’s head

          • Jeffrey Ross-Ibarra

            The paper I cited shows specifically that the effective number of ancestors of modern lines has declined during modern breeding. While it is possible this has changed in the last 20 years (the lines we sampled were no more recent than early 1990’s) I would actually expect the problem to become exacerbated as genetic markers allow breeders to more precisely move bits of the genome, making it less likely that extra diversity comes along for the ride.

          • Chad

            For example:

            “Currently, there are 45,000 accessions of G. max in ex situ collections around the world [3]. Subsequent to domestication, soybean has been subject to intensive improvement efforts over the past century. Despite the seemingly vast reservoir of genetic diversity in G. max, just 346 (0.77 %) of those landraces account for 76.29 % of the nuclear contribution of 1300 Chinese soybean cultivars released between 1923 and 2005 based on pedigree analysis [4]. Major modern U.S. soybean varieties released between 1947 and 1988 can be traced back to only 80 accessions from a small area in northeastern China. Approximately 86 % of the collective parentage was contributed by just 17 of the 80 landraces [5].”

            http://www.biomedcentral.com/1471-2164/16/671

            86% of US soybean varieties are descended from 17 landraces…all of which come from relatively small region of China. That is in contrast to the thousands of landraces that exist for soybean in Asia.

            Thats a very small percentage of the total genetic diversity in soybean and means that modern soybean varieties in the US have a rather narrow genetic basis. That severely limits the diversity of traits like disease resistance and is a potential problem.

            Its also why simply counting variety names does not tell you much about the genetic diversity. Many different varieties can be created from a limited number of parents and a narrow genetic base. As a result, development of new varieties does not necessarily mean more diversity or make up for the loss of old varieties.

            That is a major issue I have with the argument made in this article, that diversity has not been lost.

          • Jason

            Ok… You have a problem with the article. But how does that say anything about whether or not that has changed over the past 20 years? Certainly you’d have to agree that using hybrids and varieties that are NOT identical is more diverse than using ones that are. Right?

          • Chad

            That depends on the pedigree of those varieties. I can create distinct varieties that do have some differences, but have a narrow genetic base. Ultimately these varieties will share more regions of the genome in common than not.

          • Jason

            Did you really just say that “it depends” to my claim that different is more different than same?

            It depends on what??

          • Chad

            It depends on the diversity found in the parents. Even if there are “more” varieties available today, that does not in itself tell you how diverse those varieties are. If they all come from a narrow set of parents representing a narrow genetic base, then the actual diversity represented by that group may not be much greater…it could even theoretically be less…than it was 20 years ago.

            To assert that it is indeed more diverse, you would have to measure the diversity found in those varieties and compare it to 20 years ago.

            I am willing to bet, that for most crops it is not much higher.

          • Jason

            Hold on. The comparison from 20 years ago was that it was standard practice to sell the exact same product as you competitor. Now, the publication of that info has forced diversification into other hybrids. They may be similar… But less so than “exactly the same”. By any measure, that would increase diversity compared to without that issue.

            Whether it’s “much more” or not really isn’t my point.

          • Chad

            Not necessarily. Because of recombination, you can create any number of varieties which are individually distinct, but which would be no more diverse genetically as a whole than those from 20 years ago. The only way you can really say the diversity has increased is by measuring the overall diversity and comparing it to the diversity of varieties 20 years ago.

          • Chad

            I’m not really sure what the point is. If the point is that you have more varieties, but not more genetic diversity, then so what? Thats not an improvement.

          • Jason

            The point is that more varieties is the very definition of more genetic diversity.

            Edit: rather than very definition, I should have said “one measure of”.

            The advantages of genetic diversity are not linear. More is not necessarily better. There is a point where more will bring diminishing returns and eventually will bring negative returns. So… Given all of the other variables, how can you say where we are at on that curve?

          • Gene

            “The point is that more varieties is the very definition of more genetic diversity.”

            agree with chad, this may be the crux of the conflict over this so called ‘myth’

          • Jeffrey Ross-Ibarra

            I can only speak for maize. But genetic diversity with inbreds/hybrids sold by major companies has definitely declined in last 50 years. http://www.pnas.org/content/109/31/12420.short

          • Jason

            Your link seems to state the opposite.

          • Jeffrey Ross-Ibarra

            Figure 2D. Effective number of ancestors of modern lines has decreased over the last ~60 years.
            Figure 2C. Ancestral haplotypes among modern lines are becoming more similar.
            Figure 2A shows that modern heterotic groups are becoming increasingly differentiated, due primarily to decreasing effective population size and increasing genetic drift (read: loss of diversity within breeding pools).

            I apologize if that’s not clear in the text or figures — that’s our fault — but I’m quite sure what the data say, since my lab wrote that paper.

          • Jason

            Ok. I see. Figures 2A & 2B appeared to be saying that differentiation is greater and that the proportions of ancestry were spread across a greater number of ancestors.

          • Farmer with a Dell

            And therein lies the vast potential for genetic engineering to recover desirable traits from some of those neglected under-performing ancestral lines, expressing those in distinctly new varietals of our highly effective contemporary lines, thereby enhancing performance and increasing genetic diversity. So, why all the objection to GE on grounds of biodiversity, what’s the holdup?

          • Jeffrey Ross-Ibarra

            I have no objection to GE, and you’re right that could be a great use of GE. I am in favor of maintaining biodiversity, but not at all against GE!

          • Jeff Leonard

            Chad, your concerns are certainly valid, but it is also likely that many ,if not most, of those accessions are in fact duplicates or closely related. The number of accessions as a measure of diversity is as valid as counting the number of varieties in a seed catalog. A recent comparison of SNP diversity in wheat found as many polymorphic SNPs in US cultivars as the landraces they measured (lots of caveats but that is the data). I think that Matthew’s suggestion (that we now have the tools in high-throughput sequencing to actually measure diversity) is correct. I am a huge fan of the USDA’s germplasm collections and I think they could be the beneficiaries of this as they could reduce the number of redundant lines they need to maintain.

          • Chad

            I am not as familiar with the situation as I am in maize or soybean, but it seems pretty clear in those cases that there is a great deal of limited diversity in US varieties compared to what is found in landraces. If you look at the work of say Sherry Flint-Garcia, Jeffrey Ross-Ibarra, and others, there is clearly a lot more diversity than what is currently found in US maize lines.

          • Ever heard of seed banks? http://cornandsoybeandigest.com/seed/corn-and-soybean-seeds-are-being-stored-worldwide-gene-banks-and-seed-vaults

            Then of course you have hundreds of private heirloom seed clubs, wild crop ancestors etc..

            We also have technologies like mutagenesis that can increase variety.

            The diversity “crisis” is vastly overrated. I’m not losing any sleep.

          • will wipperdink

            Monsanto will somehow get their legal department to destroy all these seed banks as illegal
            don’t be so naive

          • get your hand off it

        • Matthew Dillon

          I should have said “majority” instead of “all” – but according to Dr. Major Goodman – one of the preeminent corn geneticists alive – those different make lines are almost genetically identical. I’ll look up the actual parent backgrounds this weekend and share the reference. But basically you are mostly seeing different names (numbers often) on inbreds that are nearly genetically identical. The real question is: is the issue of genetic vulnerability in key crops important enough that we need more than just names alone (all you are seeing) and actually have baseline data – true allelic comparisons?

          • Chad

            Exactly.

  • Rickinreallife

    I think the term “GMO” itself has contributed to a whole host of misperceptions including that genetic engineering as a process is a mechanism that drastically narrows species diversity. I suspect many people apply a common vernacular interpretation to the term GMO to mean a wholly artificial, monolithic genetic construct that replaces the genetics of diverse varieties of food crops that preceded it. In other words, the perception is that we once had varieties A, B, C, D, E, F, . . . etc. of say corn, with each variety having unique and diverse genetic features. But when biotech came along, we now just have 1 variety, GMO corn, and all those previous varieties are just abandoned. But genetic engineering does not replace A, B, C, D, E, F . . . . etc, Genetic engineering is a means to add a new trait to these varieties. We still have them, but we also now also have A+, B+, C+, D+, E+, F+, . . . . . That would be no different than if we brought a trait in by conventional means, say acquiring a disease resistance through a wide cross with a wild relative. We don’t abandon A, B, C, D, E, F, . . . .” We might add the new trait to each of the varieties, but we easily understand we did not eliminate the genetic diversity of those varieties, we more or less added information on top of that diversity.

    Perhaps a better term is “GE acquired trait varieties” or more simply “GE traited varieties.” Genetic engineering is essentially a means for accessing or generating genetic variation available to breeding programs, including acquiring genetic information beyond the constraints of just the genetic variation that exits within the species. Genetic engineering is not the first, only or most radical means at our disposal of having that capacity. Arguably, genetic engineering is a method to expand crop variation, not to obliterate it.

    Having said that, it is probably true that in practice, in commercial production at least, we do tend to plant and rely on only a relative small subset of varieties in any given year and from year-to-year . That is a factor of economics for two reasons: farmers will tend to gravitate toward the most commercially successful varieties and consolidation in seed suppliers may tend to narrow the range of varieties made available (though not necessarily so). But these factors would be the case with or without genetic engineering.

    The good news is that the more this is true in predominant commodity agriculture, the more it creates a valuable market distinction and entrepreneurial opportunity for operators who wish to cater to those willing to pay a premium for a more diverse, locally and culturally distinct crop sources of food items. You need the marketplace to be dominated by a preponderance of ge traited varieties to provide a meaningful and valuable distinction to non-gmo products. (Edit Add) You need a market dominated by mass produced standard products to create value in the unique, local attribute products, that goes for food or anything else. Look at the growth in the craft beer market over the past 20 years — It wasn’t that the beer choices were poison, it was that there was an awakening among consumers dissatisfied with the bland choices 3 or 4 major breweries made available. The uninspired uniformity of commodity beer was what created the market for the craft breweries.

    Our commodity food system has its advantages, its productivity and efficiency assures an affordable, secure food supply, something that is a luxury in many parts of the world. The tradeoff is the loss of diversity and cultural satisfaction. I’ve long felt that we are best served by having both robust commodity and attribute food systems in parallel, not that one or the other has to replace the other. As long as consumers are aware that you are not going to get non-commodity food at commodity prices.

  • J. Randall Stewart

    This article is exactly correct. I’m getting varieties that are bred specifically for my environment and disease pressures.

    With potatoes, there are more varieties available for me. There used to be just one Russet–the Russet Burbank. That was it. Now they are many variations available, each doing something a bit different.

    http://potatoassociation.org/industry/varieties/russet-potato-varieties

    With alfalfa, there are now varieties that have low lignin, resist certain pests or diseases, an alfalfa that handles standing water better. I can even get a variety bred to stand up to heavier equipment traffic in the field.

    http://www.americasalfalfa.com/alfalfa-varieties

    A new low-lignin alfalfa is coming out that will stay in that “prime” stage longer, letting me wait out a storm before harvesting

    http://www.foragegenetics.com/forage-innovation/harvxtra%E2%84%A2-alfalfa.aspx

    I participate in test plots for a major seed company, and I’m impressed with how may choices I have, and how many different varieties they choose from when bringing one to market.

    I have more choices than ever, specific traits (non-GE and GE) are being isolated and bred.

    There is a planter in the works that will plant multiple varieties in the same field–specific areas of the field pre-planned and automatically switched by GPS technology.

    Modern technology and understand of it is helping us raise crops that can do better in specific situation, and there is more choice now than ever before.

    • Chad

      The availability of more “varieties” can be a bit misleading. While there may be more available, oftentimes they have a smaller genetic base, having been bred from only a handful of lines. This can be contrasted to the large genetic diversity that exists within landraces.

      Consider that nearly all soybean varieties available to US farmers are bred from a genetic base of only 17 landraces…despite the hundreds that exist back in Asia.

      • J. Randall Stewart

        Thanks for the information.

        I wonder if this is overall bad or good. It sounds like it is similar to cars and tractors–the best traits are the ones being used, and they are becoming more similar to each other. (on equipment, levers, switches, and dials are all migrating to similar locations in the cab, and even cab/door/window layout that were completely different between manufactures in the 70’s are all almost the identical layout now.)

        • Chad

          Its mixed. The overall trend is that you are oftentimes getting the best combinations for traits like yield, flowering time, etc.

          On the other hand, it also narrows the basis for traits related to stress, whether biotic or abiotic. Consider the fact that nearly all soybean cyst nematode resistance is dependent on a single variant. If SCN ever evolves or overcomes that resistance, then all soybeans are at risk. Breeding in new resistance (if any exists) from an unimproved variety would require years of development.

          A similar situation is happening in wheat. Nearly all rust resistance is based on one or two gene, and there are new varieties of rust that are overcoming that resistance, creating a scramble to find new resistance.

          • J. Randall Stewart

            I’m fully in favor of more funding in Land Grant Colleges to keep education and development strong.

            From the results end, the method of dialing in traits is working well. At what point do we commercially abandon varieties that simply don’t produce well? I don’t know the answer to that, and I hope this interest in food and food production gains us more support in our Land Grant Universities.

  • Chad

    I do not fully agree with the conclusions. Just because varieties may still exist or be available does not mean that they are as widely planted as they used to be. If the same number of varieties are planted, but a larger percentage is planted to one or two varieties at the expense of the rest, then the diversity being planted has declined. You can still find hundreds, even thousands of land races for many of the major crops, but those account for only a small fraction of what is actually planted.

    The focus vegetable crops, rather than the major commodity crops also will bias the results. Commodity crops after all are the ones planted on the largest acreage, the basis for our food supply, and also the ones most likely to be genetically modified. Since the early 1900s, there have been huge declines in the genetic diversity of these crops. This has been documented in many studies. This decline was not caused by GMOs…so the argument from the anti-GMO crowd is false…however, that does not mean that the decline in the genetic diversity of commodity crops has not occurred or that it is not an issue of concern.

  • First Officer

    If there was more diversity in the past, they certainly hid it well from us consumers. In the 1960’s, you could have any kind of lettuce you wanted so long as it was Iceberg.

    • hyperzombie

      And up till the 40s eating fresh veggies was never done, they cooked the crap out of everything, to prevent diseases.

  • Andrew Porterfield

    Very interesting discussion. For consistency, I was only comparing what was called a “variety” starting with the 1903 survey–William Tracy, RAFI, the University of Georgia and Wageningen were not looking at genetic variation. It sounds like a need for comprehensive studies comparing whole genome of variants. Has that been done?

    • Chad

      It is starting to be done. Probably most extensively in Maize, as there is a great community that has put a lot of effort into this. To a lesser extent it is now being done in Soybean. For most crop species it has not been done or only in a limited way.

      I am less concerned about actual “varieties” than I am the genetic diversity, as that is the real measure of diversity.

  • will wipperdink

    how much did Monsanto pay you to write this pile of dog excrement ?

  • will wipperdink

    When companies like Monsanto start suing all the farmers into submission and Monsanto destroys all other seed lines we will have a catastrophic food collapse one day
    Monsanto is set on world domination and they will not stop until they have it.
    as woe be to the world when their rule is brutal

  • Melissa Pernell

    This is a distracting argument and ignore the real issue: GMO genomes themselves lack within species diversity and are therefore more susceptible to catastrophic failure in the face of a pathogen. Within species diversity increases the likelihood that at lease one variant is resistant to any particular disease.