“That is, in human reproduction, when sperm joins ovum, these two individual cells cease to be, and their union generates a new and distinct organism. This organism is a whole, though in the beginning developmentally immature, member of the human species. Readers need not take our word for this: They can consult any of the standard human-embryology texts, such as Moore and Persaud’s The Developing Human, Larsen’s Human Embryology, Carlson’s Human Embryology & Developmental Biology, and O’Rahilly and Mueller’s Human Embryology & Teratology.” – Dr. Robert George