Before writing this volume, I first asked if there really is any need for another volume on the evolutionary biology of senescence. The answer was an emphatic no. The basic evolutionary biology underlying senescence is fairly well described (Rose 1991; Arking 1998), as are evolutionary tradeoffs between the soma and the germline (Kirkwood and Kowald 1997) that push reproductive success over somatic survival in sexually reproducing species. The second question I asked had a positive response, however, and that is whether there was a need for a volume examining the evolutionary biology of human senescence from an evolutionary and biocultural perspective. Prior reports on the bioanthropology of human life span and senescence generally have been in chapters in edited volumes (Weiss 1981; Crews 1990a; Beall 1994; Crews and Garruto 1994) and journal articles (Borkan et al. 1982; Weiss 1984, 1989a, b, 1990; Crews 1993a). Although there are numerous volumes addressing life span and senescence from the perspectives of sociocultural anthropologists, none examines these issues from an explicitly bioanthropological perspective. Upon reading Bengtsen and Schaie's edited volume Handbook of Theories of Aging (1999) as I was working on this book, I was further convinced of the need for a volume on the biological anthropology of senescence and life span. The Handbook is a quality publication whose contributors represent many current leaders in gerontological research and the latest ideas and theories on life span and senescence. However, two aspects of this representation of current theory building in gerontology bothered me.