Error Theories Wear and Tear. Cells and tissues have vital parts that wear out. Rate of Living. The greater an organism's rate of oxygen basal metabolism, the shorter its life span. An accumulation of crosslinked proteins damages cells and tissues, slowing down bodily processes.
Accumulated damage caused by oxygen radicals causes cells and eventually organs to stop functioning.
Damage to mechanisms that synthesize proteins results in faulty proteins which accumulate to a level that causes catastrophic damage to cells, tissues, and organs. Genetic mutations occur and accumulate with increasing age, causing cells to deteriorate and malfunction. National Academy Press, 1992.