Forget worries about cloning people. In the future, technological advances will bring far more meaningful and controversial changes to our offspring, says Gregory Stock. As scientists rapidly improve their ability to identify and manipulate genes, people will want to protect their future children from diseases, help them live longer, and even influence their looks and their abilities. Stock, an expert on the implications of recent advances in reproductive biology, clearly shows that neither governments nor religious groups will be able to stop the coming trend of choosing an embryo's genes.