Dr. Theirry Vrain spend a long and illustrious career as the man: a soil biologist who helped engineer genetically modified organisms and advocated on behalf of biotech companies. But after he retired, he had the time to really study agriculture from many different angles and immersed himself in organic farming, medical herbalism, and permaculture. Suddenly, his worldview shifted, and he became significantly concerned about the impact of GMO crops.
In a TED talk given in May, Dr. Vrain lays out the case for GMOs that the biotech companies themselves make. Biotech companies claimed that GMOs would reduce the need for herbicides and pesticides, increase crop yield, have no effect on the environment, and be substantially the same as non-GMO crops.
And point by point, Dr. Vrain proves those claims to be false.
While companies could show an initial decrease in the amounts of chemical pesticides and herbicides used, simple evolution would suggest that while herbicides and pesticides killmost of the pests, they don't kill them all; more and more chemicals will be needed to kill those survivors, and the survivors will breed and become resistant. Today, there are more than 40 varieties of Roundup-resistent "superweeds" in the U.S., and some farmers have had to resort to pulling weeds by hand—a reduction in herbicide application, surely, but not the way biotech companies intended.
There is no science to suggest that GMOs increase crop yield, and many studies have shown GMO foods to cause significant organ damage in rats, so the claim that GMO crops are substantially the same can also be considered bogus.
But perhaps most alarming is Dr. Vrain's suggestion that if GMO crops can transmit their engineered genes to insects, other crops, and soil bacteria, it is reasonable to believe they can transmit the genes to the huge colony of bacteria living within every human being. Ninety percent of the cells in the human body are bacteria and could, in theory, be converted into "pesticide factories" pouring toxins into our body or producing antibiotic-resistant bacteria.