Evolutionally Theory of Aging

There are two commonly asked questions about the lifespan of humans. The first is why does the rate of aging differ so dramatically among different species of animals? The second one is why are there more short lived species than long lived ones?

Darwin's theory of evolution is the best way to understand why there are so many differences between the different species. Species who can adapt to their environment are the ones who live the longest. Long life is a great plus for an individual but in many cases doesn't help a species as a whole. Spontaneous mutations allow organisms to evolve; these mutations are random changes that take place in the DNA. The vast majority of mutations are harmful but a small number of them can be advantageous. When the external environment is perpetually changing then a high rate of reproduction can be an advantage as it means that there is a greater likelihood that a mutant offspring will be more adaptable to the new conditions.

In the majority of situations, evolution tends toward a high rate of reproduction and a shorter lifespan as these speed up the rate of adaptation. Long lived organisms are not only usually slower in being able to reproduce but they also usually survive for many years after they are not longer able to reproduce, thereby competing for resources with their younger peers.

Humans are a perfect example of long living species. There seem to be many evolutionary reasons why people have longer lifespan than other mammals. Our advance brain gives us a big advantage but full development of the brain takes a long time. We are also able to deal with negative changes in our environment by building artificial habitats; developing new ways to produce food and other was adapt the outside world to what we need. People are the only species that do not need to go through evolutionary change simply to survive in our current environment. The downside of this is that with a lack of evolutionary pressure for humans to develop a longer lifespan. The good news is that we can use our advanced brains to work on finding ways to slow down the aging process.

Aging is a complex set of processes that involve a diverse set of conditions and reactions. This is why the aging process has been very difficult to define; it is also why there are multiple theories on the process of aging. The processes of aging can be divided into two groups: the amassing of various degrees of damage to the cells and the genetically programmed process of aging.
Free radicals are the chemicals in the body that have an unpaired electron This means that they are very dangerous as they can behave in a erratic manner which can be very damaging to the effective functioning of the body.
DNA is the critical molecule of life: it is the blueprint of the creature encoded in the genes. DNA is an indispensable part of the cell. Other parts of the cells such as the proteins, lipids and RNA can be replaced if need be. DNA, if lost or damaged cannot be replaced.
Could aging be explained as what happens once cells have reached the Hayflick limit and are no longer able to divide? There is no conclusive answer to that question at this time. It seems that in certain tissues, including the skin and the lining of blood vessels the Hayflick limit may be a key to the aging process.
Is there a centralized aging clock in humans that dictates the pace at which all of the bodily systems run? Yes and No... Studies have not yet found a specific central mechanism that is solely responsible for aging. However, there is a system of development.
Certain substances that contribute to the aging process can be avoided. A good example of this is tobacco tar. Other contributory substances are not as easily avoided as they are key parts of the metabolism. The best example of this is glucose.
The majority of energy that is produced in the cells is done by the mitochondria. Cell function is dependent on the mitochondria providing energy to the rest of the system. Mitochondria are also the main factor behind free radical damage.
One of the most important defense mechanisms in the body is inflammation. It is a key to survival but at the same time appears to add to the pace of aging and the speed of the onset of degenerative diseases.
The body's metabolism produces waste on a regular basis. The majority of bodily waste is expelled through breathing, urine, feces and sweat. The most easily disposable waste is that which is composed of small molecules like urea, carbon dioxide and electrolytes.
Stress has been closely linked to the development of age related diseases and to the aging process as well. Stress response is basically a complicated adaptive reaction in the body.
Research on the prolonging of life, studies of people over 100, historical records, and common sense all show us that to live a long life you need to do at least some of the steps in this article.
The greater our comprehension of the aging process the more ways that scientists find to try to extend the average life span. Ironically, the most effective means of anti-aging intervention has been the same for the past 50 years; eating less!!