Text 681, 155 rader
Skriven 2004-11-06 17:19:00 av Tinyurl.Com/uh3t (1:278/230)
Ärende: Re: First Mutation Was Bi
=================================


> From: an588@freenet.carleton.ca (Catherine Woodgold)
> > I don't agree with this conclusion, unless you allow that a mere chance
> > closing of a catalytic loop to form the first replictor would qualify
> > as a "mutation". ...
> I would call that a "mutation".

So if there's a huge variety of species of simpile chemical catalysts,
single molecules of most of them, and huge quantities of several
species of simple chemicals, and varying quantities of a huge variety
of other species of chemicals ranging from single molecules to small
but measurable quantities, and every moment somewhere in the ocean a
random catalyst bumps into a random chemical that has some extra energy
and which has the right shape to function with that particular
catalyst, so that a reaction ensues, with some fraction of these
reactions producing new catalysts which shortly bump into suitable
input chemicals to trigger their own chemical reactions, creating tiny
"blooms" of chain-reactions which die out shortly, but one day by
chance a bloom occurs which doesn't die out before it closes a loop and
afterward grows exponentially, you'd use the word "mutation" to refer
to that chance bloom-starting event which started a perpetual bloom
instead of the usual short-lived bloom?

I'm really not comfortable with that usage of the word "mutation".

But whatever we choose to label that kind of event, that's what I
suspect happened to start the very first "just barely life", i.e.
replicator without any formal genome. In causation, it was just one of
many such random encounters between catalyst and reactant which
generated yet another random chemical, but in effect it was immense,
generating a perpetual bloom that filled the ocean instead of the usual
momentary blooms that die out almost immediately.

(By the way, a visual model I have for these "blooms" is similar to the
one I have for Stephen Hawking's proposed quantum foam whatever popping
tiny Universes into existance all the time with very rarely one of them
growing for more than a moment. Another visual model I have is the old
animation of a Uranium fission chain reaction, which below critical
mass is just random things that fizzle, while above critical mass grows
exponentially. "Critical mass" would be analagous for catalytic blooms
to a suitable niche, which is specific to a replicator rather than a
global property, although general availability of nutrients would be a
global property.)

> > Per my catalytic-cycle scenerio for the first replicator, I don't
> > regard that competition as very severe at all.
> I think it was;  and I think there was replication going
> on before there was a replicator able to grow exponentially
> in population.

If by "replication" you mean an occasional incident where one molecule
of C1 happens to catalyze the production of one molecule of C2 which
... Cn which happens to catalyze the production of one molecule of C1,
so logically we have a closed loop of C1 eventually begating C1 just by
chance, I agree such probably happened fairly frequently in some of the
largest of the many many momentary catalytic-branching-chain blooms.
These would be in catalytic niches that are not quite capable of
supporting fecundity greater than one, where by good luck a chain with
average/expected fecundity slightly less than one just manages to
accidently form a closed loop before it damps out.

However such short-lived events consume hardly any resources from the
great ocean. Also, non-catalyzed chemical degradation of the
meta-stable high-energy chemicals reaches an equilibrium with formation
of those meta-stable chemicals, so there's a mostly fixed combination
of all those chemicals sitting in the ocean for a long time, which
establishes the starting point for anything "interesting" to start
happening as a variation from that static mix. The Urey-Miller
experiment shows either a successful replicator forms within hours (my
new speculation within the past week) hence the competition is provably
not very bad at all, or if not then the static mix had a good supply of
amino acids and other good stuff that might be good food for a
replicator. It's the way you think about it. If you look at the raw
production of high-energy meta-stable chemicals, and say that's what
you need to make a replicator, then you look at all the natural
degradation and regard that as competition for resources, you get your
conclusion. But if you look at the raw production minus the natural
degradation which reaches an equilibrium mix as the starting point, and
you think about *that* mix being suitable for a replicator consuming
it, you get my alternate way of viewing it.

Somebody with funding for lab equipment etc. needs to devise a new
Urey-Miller type of experiment that doesn't get hopelessly clogged
after just a few hours of operation, which can run for weeks, where the
chemicals within it can be analyzed every few days, so that we can
learn how long it takes to reach equilibrium mix and what that mix is.
Then that mix-description can be fed into the research attempting to
learn what further chemical reactions are possible and what catalysts
turn up in the reaction products and how often chains of catalysts of
various lengths appear and how many major types of catalysts there are
altogether and how soon the pidgenhole principle would force a
catalytic-type cycle to appear due to more different catalysts produced
than there are total types of catalysts.

> I was thinking in terms of catalytic loops earlier, but
> I moved away from that.  I figured:  let's focus on an
> individual molecule.  Given the environment it's in, it
> has a certain probability of causing the creation of a
> copy of itself before it disintegrates.

I think that's too narrow a view. Most catalysts enhance chemical
reactions that produce something other than themselves. If you exclude
the vast majority from consideration, you may indeed paint yourself
into a not-gonna-work corner.

> For some it's negative: it means it causes the destruction or
> prevents the creation of another like itself.

Only in the very local neighborhood where it has any effect. Whereas an
exponential growth of replication will produce a local surplus that
diffuses out to other places and thereby eventually effects the whole
ocean, the inhibition of local production doesn't create anything to
spread out anywhere so the effect is completely local.

(Exception: If a given molecule causes the production of some other
molecule, which replicates itself exponentially, and that other
molecule inhibits production of the original molecule, then indeed that
first molecule effectively prevents more of itself through the whole
ocean, but in that case the issue is moot because we care about that
second molecule now.)

> I think there were molecules with probabilities between 0 and 1
> before one appeared that was greater than or equal to 1.

With the caveat that perhaps *never* did any molecule appear that
directly catalyzed its own production with fecundity greater than one,
I agree, for both your self-catalyzed scenerio and my catalytic-cycle
scenerio. With the probability between 0 and 1, maybe a second molecule
was made and maybe none was made, and it's very unlikely a third
molecule was made, so we have a very brief bloom if any, which only
slightly depletes local resources for a short time.

By the way, with my catalytic cycle, it isn't necessary for the
original molecule to stay around the whole time the loop is running
once around a cycle. It could be that while C1 exists, it catalyzes the
creation of two C2, and while those are catalyzing five C3 the original
C1 already decays, and then those five C3 catalyze six C1 but during
that time most of the C2 have decayed already, but the making of the
first of those six C1 starts the cycle again. The first few times
around the cycle, various species of catalysts may drop to zero
numbers, only to be replenished when the cycle works its way around to
making them again. But eventually as the cycle grows exponentially, and
varying rates of production causes the timing bulge to smooth out to be
less of a bulge and more uniform, there will come a time when all three
species of catalysts are always simultaneously present from that time
forward, even while no individual molecule of any catalyst survives as
long as the whole cycle takes to go around once.
---
ū RIMEGate(tm)/RGXPost V1.14 at BBSWORLD * Info@bbsworld.com

---
 * RIMEGate(tm)V10.2á˙* RelayNet(tm) NNTP Gateway * MoonDog BBS
 * RgateImp.MoonDog.BBS at 11/6/04 5:19:18 PM
 * Origin: MoonDog BBS, Brooklyn,NY, 718 692-2498, 1:278/230 (1:278/230)