Dow vs Canada

[2,4-D isn't just a cosmetic pesticide, it's a monoculture lifestyle. Such enormous volumes of 2,4-D have drenched the North American landscape that it has acted as a selection pressure in the Darwinian sense. For my M.Sc. I studied a plant whose populations in North America, Eastern Europe, etc., have largely developed resistance to 2,4-D. Resistance to 2,4-D has combined with resistances to some other groups of herbicides. Some characteristics of these plants change, when the plants are herbicide-resistant mutants, e.g., the soil temperature at which they emerge in the spring.]

http://www.panna.org/files/GlobeAndMailBanOnPesticidesMayFaceNAFTAtest20081022.pdf