"If the FDA approves of the fish, it will mark the first time a genetically manipulated animal would be allowed for human consumption in the United States. There’s a lot to digest in that last sentence, including the moral aspects of changing the natural DNA of animals. Cloning is controversial enough; that science reproduces exact copies of animals. Genetic modification, or GM, goes a step further and changes the characteristics of a plant or animal. Warnings about this 'Frankenstein' trend fall generally into two categories: food safety and impact on the environment. In the case of the GM salmon, critics worry that the fish could include dangerous allergens."