"Tim Tyler"  wrote in message
news:cpt9hl$tbe$1{at}darwin.ediacara.org...
> Perplexed in Peoria  wrote or quoted:
>
> > There are basically three possibilities:
> > (1).  If genetics arose early and easily, as in the theory of Cairns-Smith,
> > then no new principles are needed.  Just some clever ideas, most of which
> > Cairns-Smith has already provided.  Personally, though, I find this idea
> > unconvincing.
> > (2).  There may have been some not-yet-appreciated
self-organization principle
> > at work.  Perhaps it was based on non-equilibrium thermodynamics as the
> > Brussels school proclaims.  Or perhaps it is based on complex systems
> > theory as Stuart Kauffman seems to think.  Again, I am unconvinced.
> > (3).  Or perhaps there is no over-arching principle to explain the apparent
> > "progress".  Perhaps life arose "by accident"
or as a result of a series of
> > accidents.  This idea is unsatisfying to the scientifically inclined, but,
> > IMHO, it is probably correct.  (Yes, Mr. Hendricks, I know you disagree.)
>
> How can one distinguish the hypothesis that there's a "pressure"
> that drove the OOL from the hypothesis that it was an accident?

The word "accident" means different things to different people at different
times.  Perhaps I should apologize for using it here.  The method I
would prefer for verifying or refuting my hypothesis that the origin was
largely accidental is to wait until we have a full account of the whole
sequence of events that constitutes the origin.  Then ask whether all of the
steps in that sequence have some common causal pattern, or whether each
step occurred for its own idiosyncratic reason.  If there is a pattern, then
it was not an "accident".

For example, one theory has it that a key factor in one of the steps leading
toward life is that HCN is mildly acidic, and thus will migrate to the
side of a membrane with the higher pH, whereas NH3 is mildly basic, and will
migrate in the opposite direction.  But these facts of nature can almost
be described as "accidental" - at least as I use the word.  Each
"accident"
has its own explanation.  A series of incidents ceases to be accidental when
one explanation covers them all.

However, your interpretation of "accident" also leads to
interesting questions:

> The only way I can think of is to ask how probable the OOL was -
> and if it was a difficult, or rare process, the origin deserves to
> be described as accidental.
>
> One experimental data point bears fairly directly on the issue: the early
> origin of life.
>
> The early origin of life on the planet suggests life forms pretty easily -
> at least if you accept:
>
>   http://en.wikipedia.org/wiki/Mediocrity_principle
>
> On the other hand, the absence of extraterrestrials - and the lack of
> obvious signs of life on nearby planets are data-points that suggest
> that life may not be /that/ common elsewhere.
>
> I favour the idea that the OOL was rather easy, and that the universe
> is rather full of life.
>
> Consequently, describing life as "accidental" doesn't strike me as
> appropriate.

I agree with the logic of your analysis, though I remain unconvinced that
life is ubiquitous in the universe.  So the early origin may still be
simply a symptom of some kind of "anthropic principle".  If,
after exploring
and sampling the galaxy, we find that life is only moderately common,
that it has a variety of dates of origin, and that those planets with the
most advanced life are those where life arose earliest, then your argument
collapses.

Another issue is that we don't really know whether "life", by your favorite
definition, really arose early on earth.  AFAIK, there is no evidence bearing
directly on when genetics arose.  What we have is some debatable evidence
that cellular morphologies arose early and some even more debatable evidence
that biology-like carbon fixation arose early.  It is only an assumption,
based IMHO on lack of imagination, that these morphologies and metabolic
processes must have been driven by genetics.
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