The ability to alter the genetic code is one of the most powerful aspects of modern science. With genetic engineering, scientists can make a mouse’s muscles bigger, create animals that are virtually identical to one another, and cause mosquitoes to pass fatal genes to their offspring, halting the spread of disease-causing organisms. Advances in gene editing, the ability to directly manipulate DNA, have placed even greater power in researchers’ hands and renewed ethical concerns surrounding the implementation of genetic engineering. This comprehensive volume explores these topics, describes the methods by which scientists produce genetically modified organisms (GMOs), and highlights ethical issues associated with GMOs.