This timely volume explores evolutionary, cross-cultural, physiological, environmental, and pathological influences on variation in human biological aging. Chapters by leading experts use models traditionally unique to anthropological research in order to illuminate human biological aging as a heterogeneous and variable process. By explicitly emphasizing evolutionary biology and human variation, the book presents the fascinating perspective of human biological aging as the end result of a set of co-adapted genetic complexes associated with successful growth, development, reproduction, and parenting of offspring. While examining human life span and life-history parameters as population-level phenomena, the book also emphasizes human phenotypic plasticity as key to understanding aging. This broad evolutionary perspective is unique in biological gerontology, a field that is often reductionist in method and theory. The book is sure to appeal to students, teachers, and researchers of geriatrics, gerontology, biology and anthropology of aging, and human population biology.