DNA Swap Could Make Healthier Babies—With Three Genetic Parents

These cute little macaque monkeys may have gotten their fluffy brown fur from their father, their big eyes from their mother, and their good health from... their other mother. The scientific advance heralded in a new paper in Nature is essentially procedural: Researchers have figured out how to make an embryo that does not carry the mitochondrial DNA of its mother but that of another female instead, which could prevent diseases that are caused by inherited defects in this genetic material. But the study's immediate impact comes from the ethical questions it raises.