Our mitochondria the tiny powerhouses of our cells
One argument against the somatic mutation theory comes from observations of inbred animals. However, scientists point out that this wear and tear theory of aging comes from insect observations. The damage begins at the level of molecules within our cells. And that damage accumulates over time. For example, few cells in the wing muscles of adult fruit fly reproduce, and while weekold fruit flies can fly minutes without landing, monthold fruit flies must land after minutes.
Evidence to support the wear and tear as major cause of aging is based on the observation that with age, our proteins, DNA and other structural molecules develop inappropriate attachments or crosslinks to one another. Top of Page Some research supports this theory. Crosslinking of the skin protein collagen has been shown to be at least partly responsible for wrinkling and other agerelated changes in skin.
But more plausible model for the rate of living theory of aging harks back to the ancient belief that we possess finite amount of some vital substance and when that substance has been consumed, we age and die. The damage begins at the level of molecules within our cells. However, scientists point out that although mitochondria do indeed suffer damage from free radicals, that damage seldom triggers wholesale cell death. 11 The connection between free radical damage to the mitochondria and the broader aging process remain unclear.
Additional evidence comes from the accumulation of mitochondrial damage with aging in some insects. The crosslinking theory of aging harks back to the ancient belief that we possess finite amount of some vital substance and when that substance has been consumed, we age and die. Crosslinking of proteins in the lens of the eye is also believed to play role in agerelated cataract formation.
In fact, virtually all inbred animals have shorter life spans when compared to outbred animals. Our bodies have the capacity to repair themselves when they are damaged, free radicals can cause much irreversible damage. 9,10 Other researchers point out that this wear and tear theory of aging is based on the observation that with age, our proteins, DNA and other structural molecules develop inappropriate attachments or crosslinks to one another. The damage begins at the level of molecules within our cells. The DNA that makes up our genes sustains repeated damage from toxins, radiation and ultraviolet light.
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