Aging: Evolution's Unexpected Result

[Greg Bernhardt]

Aging is a result of evolution, not something selected by evolution, but something outside the selective powers of evolution. As research uncovers more and more about the mechanisms behind aging the exact nature of this fact is being realized more and more.

http://physicspost.com/articles.php?articleId=166

 

[Another God]

Has anyone who has read this article got any feedback for me? I intended on revising the article and writting a more publically accesible version (this version being an actual Uni Assignment). Any thoughts? Does anyone care?

 

[FZ+]

The article is very good... Though you might do well to separate it out a bit. Eg. 1 chapter on the process of aging, and one on implications.

But I don't altogether agree with some of your conclusions...

In a typical natural environment organisms die through predation, accident, starvation, infection and other such events long before aging becomes a factor [20].

True, but we have to see age as not a cut-off point, but as a gradual crawl. Though few may die actually of aging, they do weaken. Hence it is possible to surmise that the aging process gives an inherent bias in favour of younger individuals, and may hence work to accelerate adaptation, giving new characteristics a small edge, as so some processes of aging can be "useful".

 

[Another God]

Originally posted by FZ+
True, but we have to see age as not a cut-off point, but as a gradual crawl. Though few may die actually of aging, they do weaken. Hence it is possible to surmise that the aging process gives an inherent bias in favour of younger individuals, and may hence work to accelerate adaptation, giving new characteristics a small edge, as so some processes of aging can be "useful".

The point of that observation though, is to explain why aging exists at all. In a world where there was no aging phenotypes, organisms would eventually die through those sort of events. Because of that, there is no selective pressure (or a very weak selective pressure) to stop negative genetic effects which only occur later in life.

This particular conclusion is not my own anyway, it's just one tha I believe to be very reasonable. It is the theory of Medawar, Williams and also Kirkwood. The best paper to read on it is Williams' (in the references). Very easy to read and very very insightful. His paper is the origin of Antagonistic Pleiotropy theory...and yeah.. um, i'll stop ranting.

anyway, what other conclusions do you disagree with? (Of all the discussions I get into on PF, none can interest me more than this one, in case you don't yet know, this is what I intend to spend my life doing, so if you can find any faults with anything I say/think here, this is more important than just about anything to me *Nodz*

 

[FZ+]

anyway, what other conclusions do you disagree with?

Not much.

But I'll go out on a limb and oppose this:

complex side effects piled on top of each other in a somewhat random uncontrolled way

From recent studies, even cell death has been shown to be very much controlled. So, while Aging may well be a complex mixture of effects, I don't think it is really random or uncontrolled.

Bodies don't play dice?

 

[Another God]

Originally posted by FZ+
Not much.

But I'll go out on a limb and oppose this:

From recent studies, even cell death has been shown to be very much controlled. So, while Aging may well be a complex mixture of effects, I don't think it is really random or uncontrolled.

Bodies don't play dice?

BUt the cell death you mention plays a functional role in multicellualr organisms. This is age related death, this is 'Oh my God something's wrong. Abort ship!' death.

 

[FZ+]

Well... just stating an opinion. We shall see what future research brings, eh?