Small Nonhuman Primates as Potential Models of Human Aging.

Abstract

Both theoretical and practical reasons exist for developing a small nonhuman primate model for aging research (a fuller treatment of the logic of selection of animal models for aging research may be found in Sprott and Austad 1996). Conceptually, the issue is evolutionary propinquity to humans. Any animal species will bear some traits that are relatively general, that is, shared by large groups of animals, and other traits that are more idiosyncratic, or particular to more narrowly defined groups. It is an axiom of comparative biology that species with a close evolutionary relationship share, on average, more traits than more distantly related species, whether those traits are anatomical features like skull shape or functional characteristics such as mechanisms of aging (Harvey and Pagel 1991). For instance, humans share with the great apes and Old World monkeys, but with few other mammals, the age-related phenomenon of menopause (Hayssen and others 1993; NRC 1981) as well as a tendency to develop atherosclerotic vascular disease (NRC 1981). In principle, then, the most relevant animal model of any human trait would be chimpanzees {Pan troglodytes) or bonobos {Pan paniscus), equally close biological relatives of humans. However, there are insupportable drawbacks to the use of large apes as models for aging research, including their prohibitive acquisition and maintenance costs and their longevity, which can be more than 5 decades in captivity.