Here the conflict begins in the moments following conception as embryos struggle to wrest control of pregnancy from the mother, and to wring more nourishment from her than she can spare, thus triggering morning sickness, diabetes, and high blood pressure. Mothers, in return, often spontaneously abort embryos with severe genetic defects, allowing for prenatal quality control of offspring. Using a broad sweep of entertaining examples culled from the world of animals and humans, A Natural History of Families is a lively introduction to the behavioral ecology of the family.