The number of weeds that are resistant to glyphosate is increasing, because their genes can travel quickly when their pollen spreads. According to agriculture policy expert, Dr. Charles M. Benbrook, the beginnings of this environmental and economic problem can be seen in a weed called 'marestail.' Dr. Benbrook says that as a result of heavy reliance on Monsanto's Roundup, 'marestail will almost certainly be the first of several glyphosate-resistant weeds that emerge and spread,' triggering the need for the creation of a new toxic herbicide.
Some farmers are apparently willing to ignore the degradation caused by releasing so many toxic chemicals into our environment, because they need to find ways to decrease their costs. But opponents of genetic engineering argue that the only ones who benefit from genetically modified crops are the companies that sell them.