Our current understanding of the genetics of aging stems largely from 2 decades of research involving animal models. The research is yielding evidence that aging is a complicated process involving multiple genes and their interactions. It is also showing that aging and life span can be manipulated. This article highlights findings from these studies and discusses their implications. It also highlights other research on humans and aging. The author makes the point that genetic research will likely lead to longer human life spans but that change will be incremental.