Science at the Edge Genetic Modification of Food s explains how genetic engineering has led to artificial selection and the selective breeding of animals and crops. Learn about cloning, how genes are inherited, and how scientists insert genes from one organism into the DNA of another. Consider whether or not growth hormones should be given to cows to increase their milk yield and used to produce "super salmon." Discuss the issues surrounding cross-pollination, how genetically modified crops affect wildlife, and the possibility of using genetically modified oil-crops to replace fossil fuels.