"James Michael Howard" 
wrote in message news:bid9pc$cvn$1{at}darwin.ediacara.org...
> Lifespan May be Due to Hormones
>
> James Michael Howard
> Fayetteville, Arkansas, U.S.A.
>
> My work suggests evolution of animals has been
dramatically influenced by
> hormones (www.anthropogeny.com ).  My principal hypothesis
is that hormones were
> selected by evolution because they optimize replication
and transcription of
> DNA.  This accelerates the processes of DNA and.
therefore, the onset of
> reproduction.  Hormones activate the processes of the
growth program of DNA and,
> therefore, reproduction potential is reached faster.
Growth is accelerated for
> the process of reproduction, but once reproduction is
achieved sufficiently for
> the species there is no selection for extension of the
life span.  Aging is the
> loss of this process.
>
> Now, if an organism does not produce, or produces only
small amounts of,
> hormones, the processes of replication and transcription
of DNA will both be
> slow ...because they are not optimized.  Rocky Mountain
bristle cone pines grow
> slowly and reproduce slowly.  The cones appear on old to
moderately old, open
> stands.
> )  I suggest this slow growth and slow reproduction is due
to lack of hormones
> that optimize the processes of DNA.  This reference said
reproduction occurs
> mainly in "open" stands; perhaps extra sun energy is
necessary to properly
> "energize" the processes of DNA for reproduction.
>
> My work may also explain why life spans are longer in
animals living in
> protected environments.  I suggest mammals evolved due to
increases in DHEA.
> DHEA, being a DNA optimizer, is involved in all aspects of
DNA function.
> Subordinate to this hypothesis is that cortisol evolved as
the major antagonist
> of DHEA.  (I suggest this antagonism of DHEA and cortisol,
the two major steroid
> hormones of the adrenal glands, is the mechanism of the
"fight or flight"
> response.)  Cortisol is the "stress hormone."  In a
protected environment,
> reduced stress achieves less cortisol production and
reduces the effects of
> cortisol.  In a protected environment, DHEA then would
then increase its
> effects.  ...less stress, less cortisol, more DHEA.
>
> Very recently, the molecule, resveratrol, found in red
wine, among other places,
> has been connected with life extension.  Work has shown
that resveratrol and
> DHEA both inhibit "carcinogen-activating enzymes in vivo."
(I am currently
> writing about this for my web site.)  Therefore, in
animals that do not drink
> red wine, DHEA may be involved in longevity.  Animals kept
in protected
> environments may exist longer because of the protective
effects of increased
> DHEA.
>
> Mammals, compared to bristle cone pines, exhibit very
short life spans.
> However, there are very many more mammals than there are
bristle cone pines.  I
> suggest the life span is controlled by hormones in animals
and plants.
>
>
>
> On Mon, 25 Aug 2003 03:00:05 +0000 (UTC), dkomo
 wrote:
>
> >Tim Tyler wrote:
> >>
> >> William Morse  wrote:
> >>
> >> : My point (and the generally accepted theory)  is that
every organism
> >> : eventually succumbs to environmental stresses. Since
they do, evolution
> >> : cannot develop immortality genes because there is no
selection pressure
> >> : to do so.
> >>
> >> There might not be any genes that enable infinitely
long lives.
> >> However there are organisms which exhibit "negligible
senescence".
> >>
> >> Most famous are trees - e.g. bristlecone pines at 5,000
years or so.
> >>
> >> The oldest living thing is thought to be over 11,700
years old:
> >> [http://waynesword.palomar.edu/ww0601.htm#oldest]
> >>
> >> As far as we can tell such organisms don't age.  Their
chance of dying
> >> doesn't increase with age in a way that can be
measured.
> >>
> >> Effectively, they have their senescence issues cracked.
> >
> >Yes, and negligible senescence can't be explained by
Medawar's
> >Accumulated Mutations theory, nor by Williams'
Antagonistic Pleitropy
> >theory, nor by Kirkwood's Disposable Soma theory of
aging.
> >
> >The only thing that sensibly explains it is that aging is
a genetic
> >program.  These organisms have their timers set for very
long
> >lifetimes.
> >
> >By the way, in response to your other post about
Weismann's theory,
> >the evidence for genetic control of aging is coming in
straight from
> >molecular biology, and it is not dependent on whether
Weismann was
> >correct or not.  Whatever the *purpose* of senescence may
be from an
> >evolutionary standpoint, there appear to be genes that
are directly
> >controlling it.
> >
> >I too have read one of Gavrilov's papers in the past few
days.  And I
> >admit that the evidence that lifespans of animals kept in
protected
> >environments greatly exceed the
> >lifespans observed in natural conditions is a tough nut
to crack for
> >the senescence timer proposal.  I'm still working on
this.  I may send
> >an email to Joshua Mitteldorf, who is a leading proponent
of the
> >genetic program idea, and see if he has a rebuttal.
> >
> >
> >    --dkomo{at}cris.com

I find this all very interesting. As a layman, for a while
now I have been entertaining the idea that senescence and
ultimate
death is directly related to the physical limitations of
growth. It seems to me that all (non-linear dynamical, i.e.
"chaotic") complex systems, be it organisms, chemical
clocks, or weather systems, require ongoing energy input to
maintain their
organization _as well as continuing growth with time_. Where
system growth is physically limited for various reasons they
will ultimately disorganize and die, all at different rates
depending on detailed morphology and functions of course.

Any complex system strives to conserve its essential
structure from disorganization, to the extent that it can
through growth--when growth is ultimately limited, structure
begins to break down...storms, limited in extent, dissipate;
chemical clocks, also confined in space, eventually come to
equilibrium (in effect, "die") as do organisms, although
their actual persistence differs. Size and detailed
structure would seem a factor here, but the primary problem
for organisms is the physical limit on size--with our basic
form, we can only grow so tall or so wide without collapsing
and/or remaining mobile, etc. Thus, early on, animal genomes
have adapted to slow growth on aging, with the inevitable
consequence of eventually disrupting dynamically maintained
structural patterns and functions, leading to death.

The bottom line is, I think, practical limits on growth
ensure that no complex dynamic system can eternally remain
poised on the edge of chaos, exploiting incoming external
energy, without ultimately losing detailed morphological and
functional integrity on all levels.

Comments?                                          ...tonyC
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