4. Cloning could also be used to reverse the aging process. Over time cells are unable to repair and reproduce. The gradual decay and degeneration of the body that appear with aging is particularly due to this factor. Reversing the effects of aging can be done by substituting the damaged and worn-out cells in the body with newly cloned young cells of identical genetic composition as that of the individual in whom the replacement is being carried out. This process is a theory which if holds true in the future will dramatically increase the length that humans can live.