Corn farmer Jerry McCulley sprays the weedkiller glyphosate across his cornfield in Auburn, Ill., in 2010. An increasing number of weeds have now evolved resistance to the chemical. Seth Perlman/AP hide caption

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Labels on bags of snack foods indicate they are non-GMO food products. This fall, Colorado and Oregon will be the latest states to put GMO labeling on the ballot. Robyn Beck /AFP/Getty Images hide caption

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A corn purchaser writes on his account in northwest China in 2012. In November 2013, officials began rejecting imports of U.S. corn when they detected traces of a new gene not yet approved in China. Peng Zhaozhi/Xinhua/Landov hide caption

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General Mills' original Cheerios are now GMO-free. But you won't find a label on the box highlighting the change. David Duprey/AP hide caption

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A customer shops for produce at the Hunger Mountain Co-op in April 2013 in Montpelier, Vt. More than a dozen food cooperatives supported the bill that would require the labeling of genetically modified foods. Toby Talbot/AP hide caption

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A woman shops at a supermarket in New York City. Spencer Platt/Getty Images hide caption

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Allen Williams grows corn and soybeans for Clarkson Grain, which has been selling GMO-free grain to Japan for years. Dan Charles/NPR hide caption

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After Grist's six-month-long series on genetically modified foods, some loyal readers accused the site of changing directions in the debate. iStockphoto hide caption

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