The Genetics of Aging is divided into several sections in an attempt to provide a logical progression from the level of the genome to the realm of human genetics. The relationship between the genetic material and aging will be thoroughly explored in the initial chapters. These chapters discuss in depth the various theories that have been proposed for the mechanisms of aging at the molecular level and present data which either support or contradict these hypotheses. Subsequent chapters will deal with the genetics of aging in organisms ranging from paramecium to mammals. The largest section of this volume will be devoted to several important areas in human genetics: human genetic disorders which feature premature aging, the effect of human parental aging on the production of genetically abnor mal offspring, the genetics of human longevity, and a review of studies on aging human twins. Over the last few decades genetic technology has provided enormous insight into a number of disciplines. Therefore, in the last few chapters, several genetic approaches to the study of aging are discussed: somatic cell genetics, immunogenetics, and behavioral genetics. As the goal of this volume is to present a comprehensive examination of the genetics of aging, most chapters are oriented toward general review of their respective areas. It is my hope that this volume will encourage clinical, biological, and behavioral investigators to turn their attention to the genetic aspects of aging as well as to employ genetic technology to obtain further insight into aging processes.