Animal models in aging research: A critical examination

Understanding why different organisms show diverse rates of aging may provide useful insights into basic aging processes. Biogerontologists have converged on a few model organisms that represent only a minute fraction of the animal kingdom, but nevertheless span a considerable distance in animal evolution. Shared features of these evolutionary divergent animals have highlighted some conserved regulatory processes in animal aging. However, these traditional models are all short-lived and may have unintentionally constrained research to focus on only those areas in which their use is most appropriate. Surprisingly few studies focus on slow-aging organisms, or nontraditional model organisms that may be better suited to address successful aging and issues more relevant to long-living humans. This chapter critically assesses both traditional and nontraditional animal models used in aging research, and emphasizes the importance and judicious use of the comparative method to test the ubiquity of aging theories, mechanisms, and their potential translation for human application.