[extropy-chat] Re: Aging as a function of bone marrow degradation

[The Avantguardian]

--- mail at harveynewstrom.com wrote:

> 
> Is there any evidence that animals that hibernate
> live longer than animals 
> that don't?  Or that preventing an animal from
> hibernating shortens its 
> lifespan?  I am not sure that the assumption that
> hibernation slows down 
> aging is necessarily true. 

Yes. It has been shown conclusively in bats. The
abstract of the paper follows:


 Aging Cell. 2002 Dec;1(2):124-31. 

Life history, ecology and longevity in bats.

Wilkinson GS, South JM.

Department of Biology, University of Maryland, College
Park, MD 20742, USA.
gw10 at umail.umd.edu

The evolutionary theory of aging predicts that life
span should decrease in
response to the amount of mortality caused by
extrinsic sources. Using this
prediction, we selected six life history and
ecological factors to use in a
comparative analysis of longevity among 64 bat
species. On average, the maximum
recorded life span of a bat is 3.5 times greater than
a non-flying placental
mammal of similar size. Records of individuals
surviving more than 30 years in
the wild now exist for five species. Univariate and
multivariate analyses of
species data, as well as of phylogenetically
independent contrasts obtained
using a supertree of Chiroptera, reveal that bat life
span significantly
increases with hibernation, body mass and occasional
cave use, but decreases
with reproductive rate and is not influenced by diet,
colony size or the source
of the record. These results are largely consistent
with extrinsic mortality
risk acting as a determinant of bat longevity.
Nevertheless, the strong
association between life span and both reproductive
rate and hibernation also
suggests that bat longevity is strongly influenced by
seasonal allocation of
non-renewable resources to reproduction. We speculate
that hibernation may
provide a natural example of caloric restriction,
which is known to increase
longevity in other mammals.


The Avantguardian 
is 
Stuart LaForge
alt email: stuart"AT"ucla.edu

"If you fear death, you are not living right; if you don't want to live forever, you are not living well." - a sparrow outside my window.


		
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