Re: OOL X - The origin of the RNA world.

Robert Maas, see http://tinyurl.com/uh3t <rem642b@xxxxxxxxx> wrote or quoted:
> > From: Tim Tyler <tim@xxxxxxxxxxx>

> > ... if you look at the system at a random point in time, you are
> > likely to encounter it locked in a relatively stable state by
> > negative feedback mechanisms - without much sign of positive feedback
> > in sight.
>
> This appears to be nothing more than "catastrophe theory". Using a ball
> rolling over landscape metaphor: Most of the time the ball is resting
> at a relative minimum. But as the landscape changes, every once in a
> while, without any obvious warning, a relative minimum spills over a
> former pass, and the ball rolls over the edge and falls into a new
> relative minimum and oscillates wildly until it settles down at the
> minimum. No matter how stable things seem at the moment, next week
> there could be such a castrophe. Such a spillover "catastrophe" would
> be some kind of environmental collapse causing an extinction event.
> Most of the time it's a small extinction event. Some times it's a major
> extinction event. Eventually it's almost sure to be a total anihilation
> event, after which there will be no more life on Earth. How is that
> like a comforting "goddess" as Lovelock wrote??

Such "catastrophic" shifts are part of Lovelock's theory.

The conservationist take on that side of things seems to be that
that any species that is *too* disruptive will face a series of
rapidly-changing environmental catastrophes - where the fluctuations
continue until the offending species is obliterated or mends its ways.

I suppose if such disruptive species tend to get wiped out by
"mother earth" ;-) there might be a tendency for non-disruptive
species to proliferate.

> > We can be confident from the fossil record that no such periods of
> > super-instability have occurred so far in the history of our planet.
>
> Well, doh, apply the weak anthropic principle: On all planets where
> such has happened already, there's nobody alive to look at the planet
> and see the record of that super-catastrophe.

Your description of a "super-catastrophe" involved all
eukariotic life on Earth going extinct.

Such an event would certainly represent a set-back - but surely it
would not preclude the subsequent development of advanced intelligence.

> > I don't think Gaia is a particularly "futurological" theory, and so
> > it probably doesn't have much to say about the possibility of such
> > super-instability arising in the far future.
>
> Yes, that's my point: I take no comfort in "gaia" because it doesn't
> give any reason to expect us to live another ten years much less have
> descendents alive a billion years in the future. Basically "gaia" is no
> better than the weak anthropic principle: We're alive now to observe
> the past, which imples the past must have been survivable, but makes no
> comparable implication about the future being survivable.
>
> We've been lucky so-far. That's no reason to expect the luck to continue.

Gaia is a theory about the state of life on earth. It's not supposed
to be "comforting".

If anything those who support it often have exactly the opposite approach
to the theory - they think it illustrates that an ecosystem pushed too
far out of balance by a species is liable to react with cataclysmic
environmental shifts that continue until the disruptive species is wiped
out - or learns to live in better harmony with its environment.

Therefore - so the argument goes - why not realise this; and learn
the lesson *before* the reprimands begin.
--
__________
|im |yler http://timtyler.org/ tim@xxxxxxxxxxx Remove lock to reply.

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