Mitochondria, oxidative damage and longevity: What can comparative biology teach Us?

The most studied theory of aging is the oxidative stress theory of aging, and evidence supporting or disputing the theory has come primarily from investigations using common model organisms such as C elegans, Drosophila, and laboratory rodent models. However, studies using more non-traditional animal models offer an excellent opportunity to critically evaluate different aging hypotheses. The advantage of studying a broader spectrum of species is that one can significantly expand the amount of information obtained on a wide range of biological phenotypes/traits such as life span, body weight, and metabolic rate. In addition, the ultimate validity of a hypothesis/theory can be more critically tested using as many samples, in this case, species as possible. In this chapter we present evidence regarding different aspects of oxidative stress theory of aging with special emphasis on metabolic rate, reactive oxygen species generation, and oxidative damage to macromolecules. The purpose of the chapter is to initiate the integration of current knowledge and also to inspire readers to consider the advantages and power of using a comparative biology approach to study aging.