This report outlines the main theories of how the process of aging works. Since researchers have not discovered a universally-accepted theory of aging, the theories discussed are potential explanations of how we age. The likelihood of each hypothesis is considered roughly equal. The different theories discussed focus on the workings of different parts of the body, from the molecular level of DNA mutations and replication, to the organism level of becoming worn out. Aging is a very complex and gradual process, and its ongoing operation is present to some degree in all individuals. It is a journey to the maturity, as well as to the degeneration of the body. Because aging affects every part of the body, many different steps are involved and various types of reactions occur. Changes in DNA take place, which can and often do affect the way the body functions; harmful genes are sometimes activated, and necessary ones deactivated. A decrease in important body proteins like hormones and certain types of body cells is almost inevitable. These, among many, are characteristic changes that take place in our bodies as time moves on and aging continues. At present, a universal explanation for how we age or why we age does not exist, but there are many theories to explain this puzzle, and they are supported by continuous research. In this report, some of the how theories of aging will be examined. Among them are theories concerning spontaneous mutations, damage from free radicals, the clock gene, cellular aging, a weakened immune system, wear and tear, and hormonal and neuroendocrinous changes. Spontaneous Mutations The spontaneous mutations theory, also known as the somatic mutation hypothesis, states that the crucial events that cause aging are mutations. These are changes in a cell=s DNA, which are passed on to daughter cells during mitosis. Since genes on DNA code for specific proteins, mutated genes may produce defective pr...
