[ExI] Are Limited Lifespans An Evolutionary Adaptation?

[rex]

Rafal Smigrodzki <rafal.smigrodzki at gmail.com> [2015-06-19 11:43]:
>    On Fri, Jun 19, 2015 at 12:58 PM, rex <[1]rex at nosyntax.net> wrote:
> 
>      Impossible to tell without actual code. The main paper is paywalled,
>      and probably doesn't have code anyway.
> 
>    ### Well, they produced results flying in the face of reality, so it's a
>    good guess they screwed up.

How can you be sure without the numerical details? Trying to verbally
model complex systems that have multiple positive and negative
feedback loops and phase delays is futile, IMO. My bet/WAG is that a
suitable quantitative sim will show what the paper claims is
theoretically possible. If so, then it becomes a search for real
examples which -- like group selection -- are few and far between.

> 
>      Whoa! What definition of aging are you using? In the serious human
>      models I've seen, humans age markedly, and this fact is reflected in
>      the human life table. John Graunt's table is the oldest I've
>      seen. Some birds, notably seabirds, were long thought not to age
>      because they had an apparently constant rate of death, but recent
>      careful work shows that they do eventually start to age.
> 
>    ### Sorry for the simplification - of course, humans do age from the
>    moment of conception but what I meant is that under natural conditions we
>    hardly ever age enough to be killed by aging. Humans are killed by
>    predation (both micro- and macro-predation, including intraspecies
>    predation) and by accidents of the environment, most notably famine.
>    And yes, eventually every creature would age enough to die from it, given
>    protection from predators and accidents, simply because it's impossible to
>    resist the second law forever.


But what's aging "enough"? Reaction times slow, digestion efficiency decreases,
muscles weaken, etc. One day something dire happens that would have been a near
miss yesterday.

Bottom line, my bet is that a good quantitative sim will show aging is
an important factor for some values of the parameters. We can't know
without the code.

-rex
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