Emma Rosi-Marshall's trouble started on 9 October 2007, the day her paper was published in Proceedings of the National Academy of Sciences (PNAS). Rosi-Marshall, a stream ecologist at Loyola University Chicago in Illinois, had spent much of the previous two years studying 12 streams in northern Indiana, where rows of maize (corn), most of it genetically engineered to express insecticidal toxins from the bacterium Bacillus thuringiensis (Bt), stretch to the horizon in every direction.rnWorking with colleagues including her former adviser Jennifer Tank at the University of Notre Dame, Indiana, Rosi-Marshall had found that the streams also contain Bt maize, in the form of leaves, stalks, cobs and pollen. In laboratory studies, the researchers saw that caddis-fly larvae - herbivorous stream insects in the order trichoptera -fed only on Bt maize debris grew half as fast as those that ate debris from conventional maize.
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