Virtually all life on Earth, from bacteria to humans, needs iron to survive. From facilitating oxygen flow in mammals to assisting migrating birds in finding their way south for the winter, iron serves a variety of roles for nearly all living creatures. Starts with the discovery of iron-rich hot springs on the ocean floor. Explains why there is iron in our blood & describes how the body safely cages excess iron. The physiology of exercise & genetic blood diseases is delineated. Explains how the migration of birds, turtles, salmon, & other animals depends on iron magnets. Looks at global issues, incl. iron's impact on the Earth's oceans, vegetation, & pop's. & the low-protein diets that lead to long-term cognitive damage in iron-deficient children in poor countries. Ill.