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Popsci_2014 00474.txt

#Core Truths: 10 Common GMO Claims Debunkedlater this year the U s. Department of agriculture may approve the Arctic Granny and Arctic Golden the first genetically modified apples to hit the market. Although it will probably be another two years before the non-browning fruits appears in stores at least one producer is already scrambling to label its apples GMO-free. The looming apple campaign is just the latest salvo in the ongoing war over genetically modified organisms (GMOS) ne that's grown increasingly contentious. Over the past decade the controversy surrounding GMOS has sparked worldwide riots and the vandalism of crops in Oregon the United kingdom Australia and the Philippines. In May the governor of Vermont signed a law that will likely make it the first U s. state to require labels for genetically engineered ingredients; more than 50 nations already mandate them. Vermont State senator David Zuckerman told Democracy Now! As consumers we are guinea pigs because we really don't understand the ramifications. But the truth is GMOS have been studied intensively and they look a lot more prosaic than the hype contends. To make Arctic apples biologists took genes from Granny smith and Golden delicious varieties modified them to suppress the enzyme that causes browning and reinserted them in the leaf tissue. It's a lot more accurate than traditional methods which involve breeders hand-pollinating blossoms in hopes of producing fruit with the desired trait. Biologists also introduce genes to make plants pest-and herbicide-resistant; those traits dominate the more than 430 million acres of GMO crops that have already been planted globally. Scientists are working on varieties that survive disease drought and flood. So what exactly do consumers have to fear? To find out Popular Science chose 10 of the most common claims about GMOS and interviewed nearly a dozen scientists. Their collective answer: not much at all. Humans have been manipulating the genes of crops for millennia by selectively breeding plants with desirable traits. A perfect example: the thousands of apple varieties. Virtually all of our food crops have been modified genetically in some way. In that sense GMOS are not radical at all. But the technique does differ dramatically from traditional plant breeding. Here's how it works: Scientists extract a bit of DNA from an organism modify or make copies of it and incorporate it into the genome of the same species or a second one. They do this by either using bacteria to deliver the new genetic material or by shooting tiny DNA-coated metal pellets into plant cells with a gene gun. While scientists can't control exactly where the foreign DNA will land they can repeat the experiment until they get a genome with the right information in the right place. That process allows for greater precision. With GMOS we know the genetic information we are using we know where it goes in the genome and we can see if it is near an allergen or a toxin or if it is going to turn another gene off says Peggy G. Lemaux a plant biologist at the University of California Berkeley. That is not true when you cross widely different varieties in traditional breeding. One frequently cited study published in 2012 by researchers from the University of Caen in France claimed that one of Monsanto's corn GMOS caused tumors in lab rats. But the study was discredited widely because of faulty test methods and the journal retracted it in 2013. More recently researchers from the University of Perugia in Italy published a review of 1783 GMO safety tests; 770 examined the health impact on humans or animals. They found no evidence that the foods are dangerous. The second allows crops to tolerate the herbicide glyphosate so that farmers can spray entire fields more liberally yet kill only weeds. Glyphosate use has skyrocketed in the U s . since these GMOS were introduced in 1996. But glyphosate is among the mildest herbicides available with a toxicity 25 times less than caffeine. Its use has decreased reliance on more toxic alternatives such as atrazine. A 2012 paper from Iowa State university and the University of Minnesota suggested glyphosate-tolerant GMOS are responsible for monarchs'recent population decline. The herbicide kills milkweed (the larvae's only food source) in and near crops where it's applied. According to Wayne Parrott a crop geneticist at the University of Georgia the risk for neighboring farms is relatively low. For starters it's possible to reduce the chance of cross-pollination by staggering planting schedules so that fields pollinate during different windows of time. Farmers with adjacent GMO and organic fields already do this. And if some GMO pollen does blow into an organic field it won't necessarily nullify organic status. Even foods that bear the Non-GMO Project label can be 0. 5 percent GMO by dry weight. As for a GMO infiltrating wild plants the offspring's survival partly depends on whether the trait provides an adaptive edge. Genes that help wild plants survive might spread whereas those that say boost Vitamin a content might remain at low levels or fizzle out entirely. In the U s. farmers have been planting increasing amounts GMO crops since the seeds became commercially available in 1996. Corn cotton and soy hich together occupy about 40 percent of U s. cropland re the three crops with the highest GMO fraction by area each more than 90 percent in 2013. The GMO fraction by area of corn cotton and soy in the top states that grow those crops. Data from the U s. Department of agriculture. Graphic by Rebecca Lantner. Very few genetically modified crops end up on plates but the ones that do can be found in roughly two-thirds of processed foods sold in the U s. Genetically modified bacteria and yeasts are also critical to the production of some foods including many wines and cheeses. Cheeserennet is key in making firm cheeses pecifically an enzyme called chymosin in the rennet helps harden cheese. Traditionally cheesemakers use rennet from the lining of cow stomachs to get their chymosin ut an estimated 80 to 90 percent of hard cheeses in the U s. are made with bacteria modified with the rennet-producing cow gene. Corntrait: Tolerates herbicides; resists insects Total U s. crop by acreage: 85%herbicide-tolerant; 76%insect-resistant Found in: Processed foods such as crackers and cereals; corn on the cob; livestock feedcottontrait: Tolerates herbicides; resists insects Total U s. crop by acreage: 82%herbicide-tolerant; 75%insect-resistant Found in: Processed foods including salad dressings; livestock feedpapayatrait: Resists ringspot virus Total U s. crop by acreage: More than 50%Found in: Whole fruit and other productsrapeseedtrait: Tolerates herbicides Total U s. crop by acreage: More than 50%Found in: Canola oil; processed foodssoytrait: Tolerates herbicides Total U s. crop by acreage: 93%Found in: Processed foods such as cereals and breads; food additives such as lecithin; livestock feedsquashtrait: Resists various viruses Total U s. crop by acreage: 12%Found in: Whole vegetables and other productssugar beets*Trait: Tolerates herbicides Total U s. crop by acreage: 95%Found in: Refined sugarwinecertain wine yeasts have been modified to make wine production easier and prevent the production of harmful fermentation byproducts. One example is yeast strain ML01 in the U s . which prevents the production of histamines that can trigger headaches. It also improves flavor and color.**No modified proteins remain in the final product. Today's most common GMO technology RECOMBINANT DNA inserts genes into a plant's cells via bacteria or specialized delivery tools but it involves some trial and error. A new method called gene editing uses enzymes to snip out a specific bit of DNA to either delete it or replace it. This allows for more precise changes to a plant's genome. Scientists at the University of California Berkeley are already working with it to create virus-resistant cassava. Gene editing may also provide fodder for fresh controversy. Current GMO methods leave a trace behind or example a bit of the DNA from bacterium used to insert new genes. The enzymes used in gene editing don't leave such a fingerprint so future genetically modified plants will be harder to detect with tests. This article originally appeared in the July 2014 issue of Popular Science. Note (7/17/2014 6: 30pm EDT: Due to an editor's mistake a previous version of this story misstated several details about genetically modified wines and cheeses. We regret the error d

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