From: Joao Magalhaes (joao.magalhaes@fundp.ac.be)
Date: Wed Jan 29 2003 - 13:20:51 MST
Hi!
At 18:23 28-01-2003 -0800, Robert wrote:
>I had the opportunity to witness the presenation by David Harrison today [1]
>for which I had high hopes that I don't think were fullfilled. I don't think
>that he made the case for his premise sufficiently.
Really? A few years ago, he invited me to visit his group and asked me if I
wanted to do my Ph.D. with him. I found him very interesting and had a
couple of profitable discussions with him. I was told he's using QTL
analysis to map loci in mice involved in aging. Is that true?
>I think the message here may be that aging
>is a multi-factorial process (as the evolutionary biology of aging perspective
>would suggest).
I made my case before as to why I don't think aging is multifactorial. In
the context of CR, my argument would be: why assume there are different
mechanisms operating for each of the phenomena of CR when it can be all the
same mechanism. In fact, CR derives from a very simple intervention, a
decrease in caloric intake.
As for evolutionary theory of aging, I recently re-read some of the old
papers by Williams and Medawar. One surprising discovery I made was that
Medawar was actually an advocate of one or a few physiological processes as
the ultimate explanation of aging. "He envisioned the essential task of
gerontologists to be that of distinguishing cause from effect among the
multitude of observable changes in aging organisms, and eventually
isolating the presumably few ultimate causes" [Williams 1957]. So, to my
surprise, Medawar actually would agree with me--if he were alive--when I
say aging is caused by one or a few processes. In addition, modern
evolutionary theory--Kirkwood, Rose, etc.--fails to explain so many
observations--non-aging animals, single-gene interventions in mice that
delay aging--that I don't think evolutionary theory of aging should be used
as a theoretical foundation to understand the biology of aging.
All the best.
Joao Magalhaes (joao.magalhaes@fundp.ac.be)
Website on Aging: http://www.senescence.info
Reason's Triumph: http://www.jpreason.com
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