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17 June, 2014

Some Salient Facts On GMO's; Part I, Genetics

GMO plants have been a part of our diet since the early 1990's and yet many consumers do not know much about them, despite efforts to pass California's label law and much hollering and shouting in the media.  One of the interesting points in the Proposition 37 (Labeling of GMOs) debate is that the NO side (in favor of NOT labeling GMOs) did not try to sell people on GMOs (like I thought they would), but only denigrated the proposition's wording, or claimed (fraudulently) that GMOs would increase grocery bills by some obnoxious, unfathomable amount and charged that it created a whole new bureaucracy (it didn't). They did not promote GMOs as being safe, healthy or necessary.  If a voter, wanting to vote intelligently asks you questions about GMOs, hopefully some of what follows will provide you with enough data to inform them.

As I write this now, I can see this will take up more than one post, so this is the first installment.  If you find you have questions, or just a comment (perhaps a correction?), please use the blog's comment form so I can present the answers to all who have your question.  I hope we can make this an ongoing discussion. Today, a bit on genetics.   

Half of a child's DNA is from the mother and the other half from the father.  The different genes combine based on what is dominant and what is recessive.  For example, the mother has blue eyes and father has brown eyes, the child most likely will have blue or brown eyes.  Whichever the child has, we might assume that is dominant and the one not expressed is recessive. We don't need to try to figure out the situation if the kid has green eyes... Just yet.

So, for a plant, it's the same:  half the genetic material comes from the male and half from the female.  Plants have sex in very different ways from mammals, so it becomes a little more convoluted.  We'll cover most of this very quickly so hang on.  If there are two parents of the same plant that are different varieties (like a mild pepper male pollinating a female Jalapeno), it is called 'crossing.' And crossing between a GMO and non-GMO is what we want to avoid.  Like the plague.  

I.  Selfing - this is not common in the animal world, but in some flowers, the flower has both male and female parts in the same flower.  In the case of tomatoes, lettuce, peas and beans, these flowers almost ALWAYS pollinate themselves before they open; this is called 'selfing.'  These plants can be grown next to a different variety of the same plant and will probably NOT cross.  We have very little concern about the genetics becoming mixed between two plants under almost any condition.

II. Selfing or Bee pollinated - These are plants that CAN self- pollinate, but usually don't, even though they do have both male and female, they primarily depend on bees to pollinate them.  Because we know a lot about bee behavior, we can control the pollination between plants we want to avoid and force the plant to self-pollinate. This is still very easy to do.

III.  Insect pollinated only - Harder to control because these flowers probably do NOT contain male and female parts - they are one or the other - and so they must be pollinated by an insect or a human playing an insect.  Still, we know how to keep these separate easily enough.  It involves some extra effort, but it can be done. Soybeans are the number one GMO'ed crop that is insect pollinated.  GMOs have been implicated in some of the problems our bee populations are experiencing today, but there is no definitive proof as yet. 

IV.  Wind pollinated only - These are the plants we are most concerned about - corn, beets and others.  The wind carries the very light pollen for long distances and that endangers crops that might cross with pollen from GMO plants. 

One of the insidious points of GMO plants is that EVERY SINGLE CELL IN THE GMO PLANT CARRIES THE GMOed GENE.  Without going through the entire explanation of chromosomes combining between mother and father that you got in 8th grade, agree with me when I say, one half of your chromosomes are from your mother and the other from your father.  They combine in a unique way to make you - and because you get half from one and half from the other, you have a complete set. You have one for eye color from your mom and one for eye color from your dad.  You have one for hair color from mom and one from dad.  It takes the two versions of each chromosomes to make a complete set - one of each is dominant and one of each is recessive (this is a simplification, but we don't need to know more to understand the point).  In a GMOed plant, pollen from a GMOed plant gives the next generation half of the genes with the GMO trait in it. The GMO trait then becomes a part of every single strand of DNA in the next generation.

Corn pollen can travel up to 25 miles and still be viable.  No one has done that same research on beets yet.  When GMO corn was introduced, Monsanto told the USDA that corn pollen was only viable for five miles.  We had to take them at their word because no one had studied the distance at that time.  Now we have some independent research on this and guess what?  Monsanto must have just guessed at five miles because it's really twenty-five miles.  How far beets?  Don't know.  We do know that beet pollen is much lighter than corn.  And just like corn pollen, it will mate with any female flower ready to receive pollen.  Worse than corn, though the pollen from GMO sugar beets will cross with your garden beets and your chard because all three are genetically so similar they are considered the same species!  

Wind pollinated plants present the biggest challenge and there is NO WAY GMO and non-GMO plants can survive and be independent from crossing when grown in the same vicinity.  Non-GMO corn, to remain non-GMO when grown in proximity to GMO corn must be hand-pollinated to assure freedom from GMOs, a time consuming project that requires many hard diligent and motivated workers to prevent the GMO pollen from reaching the flowers of the non-GMOed corn.  Beets and chard present a much more challenging situation because the flowers are not neatly separated like corn flowers are.

How'd I do so far?  More to come in a day or two; stay tuned.

david









4 comments:

  1. This makes me wonder the standards of USDA poses on Organic Farms. You mentioned that Corn pollen travels up to 25 miles does USDA consider this? I'm not sure of USDA regulations but this scares me. I remember when I worked at Whole Foods they would talk about separating Non-organic and organic produce to avoid contamination. I know for Organic farmers proximity to GMO farms has always been an issue, should or does the USDA consider this crucial fact about pollination? Are these farms simply separated but still in the same general area like the Whole foods produce?

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    1. Hi Jasmin, thanks for your comments. Note: the USDA has no 'standards' on GMOs. It does have 'standards' on organic - and organic does not include GMOs. Wind pollination only concerns us with corn, beets (because GMO sugar beets will cross with garden beets and chard). The other GMOed plants, summer squashes and soybeans are primarily insect (primarily bees) pollinated. We know a bee, when necessary, can fly as much as 5 miles for forage. But that is only if there is not enough forage near the hive. In most cases, then, it is a rare bee that flies anywhere near 5 miles, so farmers have much more control over that kind of pollen. I am much more concerned about wind pollination, for the reasons I suggest in the article. There is no other produce that we are concerned about because there is no GMO counterpart. Yet. Does this help?

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  2. You did great, David! How proponents of GMO's never claimed it was safe to unpacking the real deal on how GMO wind pollination could, strike that, will impact generation of plants and animals to come. BTW find Plants selfing far outweighs our recent human preoccupation with selfies, hands down:)

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  3. Got it Mr. King. GMOs are more complicated than I thought. GMOs make my head hurt.

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