Message-ID: <241@hocsj.UUCP>
Date: Fri, 9-Nov-84 13:11:37 EST
Article-I.D.: hocsj.241
Posted: Fri Nov  9 13:11:37 1984
Date-Received: Sat, 10-Nov-84 21:06:01 EST
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I have been giving some thought to the process of the first development
of life and this morning I realized that I had been leaving out an
important step.  I had been more or less thinking of it as a process
with two major steps.  One is the creation of life from amino acids on a
micro-level, the other is the evolution of that life into an intelligent
being.  Both are very low probability events and each model must be
repeated mega-many times before intelligent life can come about on a
planet.  Because of this, I find it highly unlikely that any two
intelligent races will ever meet in the universe.  There may be more
than one intelligent, race but the probability of them being close
enough to find each other is very low, in my estimation.  (Not to
mention the low probability that they would recognize each other as
intelligent.)  The first step, I am told is not quite as amazing as I
thought because the constituents of life as we know it, the amino acids,
are more common than we may have thought in the past.

That was my thinking up to this morning.  Now it strikes me that I have
been glossing over a pretty complex step, one which is likely to have a
lower probability than either of the ones mentioned above.  That is the
step of going from something that is merely alive to a self-reproducing
(SR) cell.  This, it seems to me, is the biggest step of the three.  It
is one thing for the amino acids to form something that in some abstract
sense is alive, it is quite another for this thing to be an SR organism.
I have never looked into the mathematics of SR automata, but my guess is
that it is pretty complex.  In the evolution of life on a planet, it is
not sufficient that life come about, but also that it can outlive the
single organism.  Even assuming that lightning strikes the right amino
acids and they start squirming, that is a long way from the organism
created actually being SR.  Of the three probabilities:

    P(life forming)
    P(new organism is SR given that it is alive)
    P(SR, living organism evolves into an intelligent form of life)

I judge the second to be the lowest.  It is hard to judge the first
which seem almost mystical, but I can accept that it is a matter of
amino acids forming and adding electricity as was whimsically described
in the Julia Child Primordial Soup film some of you might have seen.
The tide of opinion in articles (and films) seems to be that it might
not be such a low probability event.  I have come to accept that the
third probability is not all that low.  Nobody talks much about it that
I have heard, but the second probability it seems to me could well be
the smallest of the three.  Any comments?

[Incidentally, anyone wishing to build up brownie points with their
personal deity by claiming credit for Him/Her/It for having done it all,
you can send these comments to me directly by writing them into
/dev/null.  I don't rule out the possibility, of course, but it all
comes down to faith and has little place in a scientific discussion.
Usually the arguments come down to say I should read what some person
said in a book rather than going out to nature and looking at the
evidence that the deity, if there is one, created with His/Her/Its own
hand.  It is another whole farble, of course, but if someone believes in
a God, then they should believe the fossil record was created by that
God much more directly than any book ever printed.]

					(Evelyn C. Leeper for)
					Mark R. Leeper
					...ihnp4!lznv!mrl

Message-ID: <644@loral.UUCP>
Date: Mon, 12-Nov-84 01:17:57 EST
Article-I.D.: loral.644
Posted: Mon Nov 12 01:17:57 1984
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  The question raised in the original posting is so complex that it defies
  any sort of simple answer, so I will keep my note brief (also this is
  going to multiple news groups, and doubtless cluttering up other wise
  useful disk space).

    o There seems to be a fair amount of controversy regarding the
    probability of live arising out of the primevil soup.  The best that
    can probably be said is that the probability is unknown.

    o In the last issue of Scientific American there was an article on
    Prions.  Prions are infectious particles which seem to reproduce.
    They have, as yet, been unable to find any DNA or RNA associated with
    Prions.  If it is indeed finally shown that Prions do not contain DNA
    or RNA, it suggests that a Prion like form might have been the step
    between the primeval protiens and a more complex organisum with genetic
    memory.

    o Intellegence has survival value, so I do not think that it is a valid
    assumption that intellegence is rare.

    o Intellegent life could have arisen many millions of years ago and
    either progressed on to something else or wiped itself out.

    o While you are thinking about questions like the origin of life think
    of this:

      There is a theory that the universe is cyclic.  It arose from the
      primal monoblock (something like a huge black hole, which contained
      the entire universe) and will eventually contract into another primal
      monoblock.  From there it will explode again, creating yet another
      universe.  If this creation of new universes goes on without end all
      things will happen, since there is an infinity of time.  Not only
      will all things happen in this infinity, but they will happen an
      infinite number of times.  This means that even though the
      possibility of you existing again is infinitely small, in an infinity
      of time it will happen.

   I did not want you to run out of philosophical questions to ponder.

			       Ian Kaplan

Message-ID: <10770@gatech.UUCP>
Date: Mon, 12-Nov-84 22:07:02 EST
Article-I.D.: gatech.10770
Posted: Mon Nov 12 22:07:02 1984
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Indeed, it is an extremely complex thing.  However, the probability of 
complex living organisms evolving ( coming into existence ) is actually very
high, say 1, since it has occured, for whatever reason.

-- 
Carter Bullard
ICS, Georgia Institute of Technology, Atlanta GA 30332
CSNet:Carter @ Gatech	ARPA:Carter.Gatech @ CSNet-relay.arpa
uucp:...!{akgua,allegra,amd,ihnp4,hplabs,seismo,ut-ngp}!gatech!carter

Message-ID: <427@houxj.UUCP>
Date: Tue, 13-Nov-84 17:49:47 EST
Article-I.D.: houxj.427
Posted: Tue Nov 13 17:49:47 1984
Date-Received: Wed, 14-Nov-84 05:39:32 EST
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Is the mechanism of DNA/RNA reproduction understood well
enough that someone could create other molecules with
similar reproduction abilities ?  Has someone at least
determined that similar molecules can be built from other
elements ?  I assume that actually building such a big
molecule from scratch is beyond present-day capabilities.

					Bill Dietrich
					houxj!wapd

Message-ID: <2565@dartvax.UUCP>
Date: Wed, 14-Nov-84 03:30:47 EST
Article-I.D.: dartvax.2565
Posted: Wed Nov 14 03:30:47 1984
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References: <241@hocsj.UUCP> <10770@gatech.UUCP>
Organization: Dartmouth College, Hanover, NH
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   (-:)     >

> Indeed, it is an extremely complex thing.  However, the probability of 
> complex living organisms evolving ( coming into existence ) is actually very
> high, say 1, since it has occured, for whatever reason.
> 
> Carter Bullard

Perhaps, then, we should ask "what percentage of solar systems in the 
universe (galaxy/within 500 light years of our sun/etc) will develop
'complex living organisms' (whatever *they* are)?"

Now and then I hear estimates from people like Carl Sagan and people who
enjoy speculating about UFO's suggesting that the galaxy is teeming with
intelligent life.  I always wonder where these estimates come from.  How
do experts decide whether or not a star is capable of supporting life?
(And not just life but 'interesting life'.)  How close to the star does 
a planet have to be to support life?  How far away?  Do you need the planet?
How likely is it that a planet is in this range?  What sort of an atmosphere
does the planet need?  Is an oversize moon necessary?

Unfortunately, I think we will only be able to guess at these answers
until we meet our first alien civilization, and I don't see that 
happening in the forseeable future.

By the by...  I hear rumours that some secret government agency has
actually found pieces of a wrecked spaceship and alien bodies and everything!
I don't suppose any of you out there in netland work for this government
agency and would like to spill some beans?  (:-)

dartvax!chuck

Message-ID: <134@psivax.UUCP>
Date: Wed, 14-Nov-84 18:16:12 EST
Article-I.D.: psivax.134
Posted: Wed Nov 14 18:16:12 1984
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<>

> I have been giving some thought to the process of the first development
> of life and this morning I realized that I had been leaving out an
> important step.  I had been more or less thinking of it as a process
> with two major steps.  One is the creation of life from amino acids on a
> micro-level, the other is the evolution of that life into an intelligent
> being.  Both are very low probability events and each model must be
> repeated mega-many times before intelligent life can come about on a
> planet.

The evolution of "intelligent" life has little to do with "probability".
The prime controlling factor in evolution is *biological selection*
NOT chance, thus if the right combination of ecological circumstances
occurs then "intelligent" life WILL evolve. It is a recognized principle
of evolutionary science that similar circumstances produce similar
organisms.  Witness the similarity between the marsupial wolf and the
timber wolf, which are only distantly related; or the similarity between
the rat kangaroos and kangaroo rats. And it is a principle of ecological
science that similar climates produce similar ecologies, often with
completely different organisms.  Witness the occurance of "chaparral"
type scrublands in California, Chile, Southern Europe, and Southern
Australia, all with completely unique species of plants. Thus a planet
with a similar climatic history to Earth has a HIGH probability of
eventually evolving "intelligent" life.

> That was my thinking up to this morning.  Now it strikes me that I have
> been glossing over a pretty complex step, one which is likely to have a
> lower probability than either of the ones mentioned above.  That is the
> step of going from something that is merely alive to a self-reproducing
> (SR) cell.  This, it seems to me, is the biggest step of the three.

It is not a *seperate* step, most biologists consider self-reproduction
to be a necessary(but not sufficient) condition for life, thus
something that is not SR is not alive, by definition.

Thus instead of:
>     P(life forming)
>     P(new organism is SR given that it is alive)
>     P(SR, living organism evolves into an intelligent form of life)
we have:
	P(life forming)
	P(evolution of "intelligent") life)

Of these the first is very high, perhaps even 1.0 given a planet
with liquid water and a high carbon content in the atmosphere.
That is on the right sort of planet the formation of life may be
almost certain, due to the structure of the universe.
The second is probably somewhat lower because chance does play
a small role in evolution - because there is usually more than
one evolutionary solution to any given problem - BUT it is still
a fairly large probability.

					Sarima Noolendur
					sdcrdcf!psivax!friesen

Message-ID: <119@spp1.UUCP>
Date: Thu, 15-Nov-84 11:40:32 EST
Article-I.D.: spp1.119
Posted: Thu Nov 15 11:40:32 1984
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> Indeed, it is an extremely complex thing.  However, the probability of 
> complex living organisms evolving ( coming into existence ) is actually very
> high, say 1, since it has occured, for whatever reason.
> 
> -- 
> Carter Bullard

I don't know what to say exactly to this statement. Am I missing some
logic link or can you really state the probability of something coming
into existence by a certain method soley on the fact it is in existence?

I guess I can now advance my pet theory about the grand canyon coming into
existence by a prehistoric giant urinating on arizona because, indeed, the
grand canyon exists.

			Mike Johnston

Message-ID: <6176@mcvax.UUCP>
Date: Wed, 14-Nov-84 06:43:45 EST
Article-I.D.: mcvax.6176
Posted: Wed Nov 14 06:43:45 1984
Date-Received: Sat, 17-Nov-84 19:39:16 EST
References: <241@hocsj.UUCP> <10770@gatech.UUCP>
Reply-To: lambert@mcvax.UUCP (Lambert Meertens)
Organization: CWI, Amsterdam
Lines: 23
Summary: Points out fallacy in estimating probability

:
> Indeed, it is an extremely complex thing.  However, the probability of 
> complex living organisms evolving ( coming into existence ) is actually very
> high, say 1, since it has occured, for whatever reason.

The probability of a continent coming into existence, shaped exactly
like North-America, is very high too, since it HAS occurred, for
whatever reason.  The probability of such a continent existing
elsewhere in the universe (especially if we define the Twin Towers
etc. to be part of the shape) is not that high.  If life on Earth
counts, the probability of living organisms having evolved is 1 and
not less.  If we try to estimate the probability of life evolving
elsewhere, the information that it happened here (once) does not
increase that probability one bit.

     Lambert Meertens
     ...!{seismo,philabs,decvax}!lambert@mcvax.UUCP
     CWI (Centre for Mathematics and Computer Science), Amsterdam
-- 

     Lambert Meertens
     ...!{seismo,philabs,decvax}!lambert@mcvax.UUCP
     CWI (Centre for Mathematics and Computer Science), Amsterdam

Message-ID: <1215@dciem.UUCP>
Date: Mon, 19-Nov-84 19:30:40 EST
Article-I.D.: dciem.1215
Posted: Mon Nov 19 19:30:40 1984
Date-Received: Mon, 19-Nov-84 20:57:11 EST
References: <427@houxj.UUCP>
Organization: D.C.I.E.M., Toronto, Canada
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==============
Is the mechanism of DNA/RNA reproduction understood well
enough that someone could create other molecules with
similar reproduction abilities ?  Has someone at least
determined that similar molecules can be built from other
elements ?  I assume that actually building such a big
molecule from scratch is beyond present-day capabilities.
==============
Logically, it isn't necessary that molecules reproduce themselves.
What is required is that in their presence (or presence in the recent
past) the likelihood of finding another such molecule increases.

Surface catalysis might lead to such conditions.  Imagine a scenario
involving something rather like a crystal (viruses can form crystals,
so they are not limited to just non-living material).  On this surface
molecules of another kind can form by selective adsorption or some
such mechanism.  These other molecules can themselves seed new crystals.
Or again, think of the clay-surface catalysis that has been proposed
for construction of complex molecules.  If there happened to develop
a molecule whose presence on the surface slightly improved the catalysis
for making more of the same, the result would be sufficient to permit
evolution of better self-replicating systems.

Whatever happened, it's a pretty good bet that catalysis of one kind
or another was involved.
-- 

Martin Taylor
{allegra,linus,ihnp4,floyd,ubc-vision}!utzoo!dciem!mmt
{uw-beaver,qucis,watmath}!utcsrgv!dciem!mmt