Why we age – a new evolutionary view
This article introduces a new evolutionary theory of aging, which suggests that aging is the result of imperfections in cell turnover in organisms. Some of the simplest animals demonstrate the strongest ability of cell renewal and therefore, according to this theory, their aging often seems to be negligible. Evolutionarily related organisms (e.g. mammals) share similar abilities in tissue cell turnover but they differ in the rates at which the process is performed. These rate differences are more or less forced by the speed of irreversible damage (e.g. lipofuscin) increase in their cells. This speed is the result of an evolutionary trade-off of “function vs. resistance to irreversible damage” in their cell molecules. The article also offers an explanation of the differences in basal metabolic rate between different species. Put simply, while a trade-off in irreversible damage plays a role in aging, the trade-off in reversible damage plays a role in basal metabolic rate.