Summary of Understanding the Odd Science of Aging

        This article talks about a natural process in which all living creatures, including humans, have to undergo. This article is about aging. It details the reason why we must all age as well as some theories on how this process occurs as well as some factors which can contribute to why different people age differently from others.

       Before exploring deeper into the many different reasons on how aging occurs, we must first know why we age. The reason why we age is due to evolutionary biology where it is explained that aging is characterized as a progressive and generalized impairment of body functions which will lead to an increase vulnerability to the environment as well as diseases. It can also be described as a loss in fertility. Thus it can be associated to evolution through the loss of Darwinian fitness, which is the term used to describe how successful an organism is at passing on its genes.

       After that, this article poses a question on whether or not the aging process is pre-programmed in us. The main reason why it is said that we human are programmed to age is so as to prevent overpopulation as well as to aid in evolution by securing a turnover of generations. But this argument is flawed in the sense that if aging is associated to genes, through evolution, it is possible to eliminate aging altogether. But this throughout the ages not one living organisms does not age, thus proving this theory wrong.

       Another reason why aging cannot be programmed is explained through the “mutation accumulation” theory which was coined by Medawar in 1952. This theory shows that natural selection is not a factor, as it holds no power, of aging. This is because it has no influence to survival in old age. Though there is hardly any evidence of a specific gene which is related to aging, there is though a lot of support for the kinds of physiological connections related to aging which was suggested by Williams in 1957. This physiological connection is further explained through the “disposable soma” theory which states that to maximize Darwinian fitness; organisms allocate their metabolic resources, mainly energy, optimally between repairing and maintenance of its soma and other functions.  This theory is a much better theory compared to the evolutionary genetic theory as it makes specific predictions on the biological process of aging.

   

       After discussing about all these theories about why aging cannot be programmed, this article went into the causes of aging. Based on this article, the aging process involves many different mechanisms at many different levels. But, one thing about these mechanisms is that they are mostly theories but they are still very insightful. The first thing that was discussed is the theory on molecular mechanism of aging which is furthered separated into five different theories. These theories are the Somatic Mutation Theory, Telomere Loss Theory, Mitochondrial Theory, Altered Proteins Theory, Waste Accumulation Theory and the Network Theories of Aging. All these theories, as said above, try to explain the different mechanisms involved in the aging process. Aside from these theories, another cause of aging is due to cellular aging.

       This article also diverges into how it is possible to modify the rate of aging. This is possible due to a discovery in 1997 where a gene which is responsible for Werner Syndrome was a genetic defect which can contribute to aging. The discovery of this genetic defect shows that genes may play a role in controlling aging.

       But after trying to explain that aging is pre-programmed, this article suddenly says that the idea may not be as far-fetched as it seems as this idea holds some truth. This is proven through some test tries to prove that certain organisms are likely to have a programmed rate of aging. Among these are the Semelparous organisms, which reproduce only once. There are also other factors which suggest that aging is programmed. Some of these factors are such as extrinsic mortality and life span, non-aging species and the aging of unicellular organisms.

       In conclusion, I find this article very interesting as it deals with an aspect of life all people fear. It gives a lot of information that may one day help in truly understanding this very confusing aspect of life. Though this article mostly deals with theories on aging and not much hard evidence, but I think that this article serves as a starting point to fully understand the biological process of aging. 

By: Pei Jun

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doi:10.1016/j.cell.2005.01.027