Aging and senescence are two concepts of biological evolution that usually occur simultaneously. Aging is an inevitable process among all humans and animal species. The survival method and length may be different, but the body’s equipment will begin to deteriorate with time. Time is a process that cannot be reversed biologically or socially; therefore the body adapts overtime to such processes. In this, how the body is treated over time will result in rapid or reduced aging. The body will still age, but the rate of deterioration will be decreased. All of these mechanisms play into all bodily functions, the only separation is depending on the person, their diet, their physical activity and genetic makeup.
One in every 100,000 persons survive as long as 120 years old. Most men and women will not live to see this age. The average age for men before developing signs of senescence in 70 years old. At 70 years of age, Alzheimer’s and other degenerative conditions began to take its peak conditions. As mentioned earlier, the life conditions are based on the individual and his or her lifestyle. In an article entitled, “Late Life Human Development: Boosting of Buffering Universal Biological Aging” Kolling and Knopf introduces biological aging and senescence by describing telomere length (TL), theories of aging (evolutionary, stochastic, and deterministic), and free radical involvement.
In evolutionary aging theories, Weismann elaborates upon the idea of natural selection. This theory promotes Darwin’s ideas, but also the idea of group selection. Group selection states that aging benefits the group, even though it may be detrimental to the individual. He later proved this theory to be discrediting and presented the idea of disposable soma theory instead. This theory states that the organism separates germ and soma in order to maintain reproductive power due to evolutionary pressure. We all know this to be true, seeing as if the soma cells are all other cells other than the reproductive cells, and that reproduction only takes place during a certain lifespan, and it is not presented as an opportunity after a certain age in certain groups of men and women. Moving along, stochastic aging theory relies on the core idea that while individuals age, a significant amount of biological damage is accumulated over time in a random fashion as a by-product of normal living. My favorite of the three stochastic theories is the “wear and tear theory”. It proposes that the usage of the body and over time, cumulative damage occurs within the body leading to death of cells, tissues, organs, and finally the organism itself. Next, the “free radical theory” expounds upon how free radicals are produced during aerobic respiration later causing rapid death. These radicals place a threat to the aging organisms because of oxidative damage.
Finally deterministic aging theories presume that aging occurs because of genetically and endogenously programmed processes. One example is the absolute metabolic scope theory. This is a rather old theory which states, that the greater an organism’s oxygen basal, the shorter the lifespan. In all of these theories, they relate to telomere length of an individual’s chromosomes. In a study, longer telomeres at baseline were associated with reduce risk of death and dementia; however, research on the associations between telomere length as a predictive biomarker of mortality is still controversial.
Kolling, T., Monika Knopf (2014). "Later Life Human Development: Boosting or Buffering Universal Biological Aging."' GeroPsych Review. vol 27. (3), 103-108.