Anders Sandberg wrote:
> Reasonable. It seems that it is partially linked with evolutionary
> path, but it can apparently be turned on and off depending on
> selection among fishes.
My theory is that some species never aged (in a evolutionary scale)
while others started to show signs of aging and then "evolved" towards
non-aging species (they evolved because they were close to the top of
the food chain or had other kind of non-hazardous lifestyle where there
is evolutionary preassure against aging). We, in turn, become so complex
that errors in our more advanced functions are more likely to occur.
Aging is caused by this errors and the ones mentioned ahead.
> > For example, do you know that mammals can't produce
> > ascorbic acid (a powerful anti-oxidant)? Little mistakes like that might
> > be behind aging!
>
> Possible, but I doubt it. We usually get enough ascorbic acid from our
> food, and excrete the surplus in our urine, so being able to produce
> would not be a major advantage. I seem to recall that some mammals can
> produce it, but I might be wrong.
The ascorbic acid is just an example, the fact is that a simple
metabolic process might be the cause of aging. A metabolic process that
occurs without errors in non-aging species (for example, tiny portions
of free-radicals might be the cause of aging, minimal differences in the
concentration of ascorbic acid might cause small cellular damages that
cause aging). Of course this is very optimistical, but I am more
convinced now than I was a few months ago that a few genes might be the
cause for aging.
This errors are different than the ones I mentioned above, these are
errors in processes that can be corrected (on a optimistical base).
Other cause of genetic errors might be our more advanced functions (like
I mentioned before), this errors are surely much harder to correct (if
they exist, and I think they do weather in the form of aging, or in the
form of inevitable lethal diseases that affect the elderly --
Alzheimer's disease, mad cow disease, some types of cancer, etc).
Tony B. Csoka wrote:
> As far as I know, though,
> Galapagos totoise cells do have a limited lifespan in culture - they are
> not immortal.
True, around 175 divisions when compared to 50-60 divisions in our case.
> I have not seen results for reptile, lobster, or fish cells
> grown in culture.
Neither have I, if you find any, please let me know.
See ya,
--
Hasta la vista...
"Life's too short to cry, long enough to try." - Kai Hansen
Reason's Triumph at: http://homepage.esoterica.pt/~jpnitya/