Most scientists agree that the main sefery issues of genetically engineered crops involve not people but the enveironment. Allison Snow is a plant ecologist at Ohio State University known for her research on "gene flow", the natural movement of plant genes from one population of plant to another. She worries that genetically engineered crops are being developed too quicky and released before they've been adequately tested. On the other hand, advocates of genetically engineered crops argue that some genetically modified plants may actually be good for the land by offering an environmentally friendly alternative to pesticide which tends to poliat water and harm animals. Far less pesticide needs to be appliesd to cotton plants that have been genetically modified to produce their own natural pesticide. While applied chemical pesticides kill nearly all the insects in a field, biotech crops pesticide only harm insects that actually try to eat those crops, leaving the rest unharmed.