First we accept the fact that there is no Darwinian natural selection
> untill after the first replicator.

I agree. However there was a more primitive kind of selection going on:

TH
Now you are in a gray area. My point was many refuse to allow any selection
outside of Natural Selection -
no gray areas allowed. 
Strictly speaking most believe there is no selection outside natural selection.
Thus everything before that was a fluke and had no selective advantage over
anything
else. Also it was in no way adapted to its environment -
adding even a smaller chance of survival. My point was that fluke factor
invalidated that strict idea of the origin. It could not happen. There is no
possibility of
a no selection world leading to a replicator.

But you, like me suggest another type of selection.
In my second post I suggest two phases to that -
that I hope you will comment on (sun selection then
sun selection plus chemical selection)
----

RM
Whenever a particular chemical reaction naturally takes place a lot,
its products tend to increase in quantity, while it's input tends to be
consumed and decreases in quantity. Whenever more than one reaction
produces the same product, or consumes the same input, their reaction
rates are additive, so that particular product increases in total
quantity, and that particular input is consumed moreso. Finally,
chemicals that are more stable tend to stay around longer after formed
before they spontaneously break down, so their quantities remain larger
than others which have already broken down.

TH
Now wait a minute. What environment is this in?
Remember, unless you have some adaptation to this
environment (and according to what I'm reading from you
 - it is not likely that any particular product no matter how important to life
- would survive. It would have
no selective advantage over anything else that I can see.
In this no adaptation period - zircons are the clear winner (they last 4
billion years) - not prebiotic material.

RM
As soon as the first replicator appears the rules suddenly change:

TH
Yet still even our first replicator is not in anyway adapted to the environment
it is in. It will be destroyed
There is no reason why it would not be. It does not
have time to adapt. There is no safe time when it is
safe from the environment. There is no reason it would
survive a day. It appears - is burned up - end of story.
Or it appears - produces repliates - all are burned up - end of story.

RM
 The
balance between that replicator's ability to make more of itself,
combined with availability of input, compared to the tendancy of that
replicator to spontaneously break down, is crucial. Most likely,
assuming the first replicator is simply an auto-catalytic cycle,
breakdown is near zero compared to ability to run through the cycle to
make more of self, so the quantity of that replicator is almost
entirely determined by the quantity of the particular input which is
most limited in quantity, which is driven to near zero remaining
quantity by total consumption of it by the replicator. So from that
point forward, quantities of any direct or indirect product of that
replicator are greatly increased, quantities of the critical input are
reduced to near zero, and quantities of the other inputs are reduced to
match the reduction in the critical input. If variation of the
replicator is possible (while remaining capable of replicating), then
mutation and natural selection can occur from this point forward.

TH
So it  is in a safe vacumn from any environmental
pressures until it has a million years of adaptation
to that environment? 
My point is that natural selection is a slow process of
adaptation, and our first replicator does not have time to adapt. It is
vulnerable and will be destroyed in the environment.

I think you will then agree with me. That FIRST we put the horse before the
cart - that is, first  prebiotic material is that which is 
sun selected to survive the environment (it has no ability to do anything else
yet)

Then, it has endless time to go through a chemical selection period. And again
because it is not destroyed
by its environment (sun cycle selection) it has time to form variants that set
up a chemical selection.
This favors those chemicals that can best adapt to that
sun cycle, and perhaps do more with that constant energy source than just
continue to exist.
And finally THEN we get our first replicator.

Note not one minute of all this time was prebiotic
material vulnerable in this environment. That is 
because it was - from day one - that which was best
adapted to the sun cycle (sun selection) then
adapted to the sun cycle through sun selection + chemical selection - then
adapted through all 3: sun, chemical and natural selection, to the environment

I think we both agree that to depend on natural selection alone - and that only
after the appearance of a replicator - is a fluke that could simply not happen.

(TH)
> Then we have no reason why any of the following would be selected
> over any non organic or non prebiotic material or over any other
> prebiotic material: monomers, polymerization of any amino acids to
> peptides or nucleotides to RNA, or sugar phosphates, and bases to form
> nucleotides, or any metabolic system, or any ribozymes, or enzymes, or
> cells or cell-like structures,

RM
All correct.

TH
> and finally no first replicator.

RM
Incorrect. None of those other things you mention are at all necessary
for a replicator to form. 

TH
If the first replicator is not adapted to its environment
it won't last an hour - nor will its un adapted children.
Nothing happened in a vacumn. And I find it unusual
that people talking about natural selection the basis of all evolution and all
life would forget
about adaptation before the first replicator - throw it
right out the window. FIrst prebiotic chemicals survive
the sun cycle (the horse before the cart). Then the cart comes next. IT can't
work the other way.

RM
See the discussions we had a few months ago
about branching catalytic chains which by chance eventually form a
closed loop (some product far down a chain happens to be the same as
some intermediate product further up toward the start of the chain).

By the way, the appearance of the first replicator in large quantity
can be quite sudden. Here's one possible scenerio: 

Th
Your scenario can't hide from my sun - it'll be destroyed
the first hot afternoon, because it is not adapted to
the environment under this limited scenario.


RM
Some catalyzed
reactions are very slow because the inputs aren't readily available so
the catalyst sits around a long time waiting for some action. Other
catalyzed reactions are very fast because the inputs are indeed readily
available, so the moment the catalyst appears it immediately has plenty
of work to do and cause the reaction to occur many times before the
catalyst randomly breaks up. So as the catalytic chain grows, some
places it stalls for a long time because no input is available for the
next link so the endpoint catalyst sits there at the end of the chain
for a long time. Other places, as soon as the chain is extended to
include a given catalyst, that catalyst immediately finds input and
goes to work, making lots of output products, some of which themselves
have catalytic properties thereby extending the catalytic chain. So my
scenerio (my "Just So" story) goes like this: There's a potential
catalytic cycle A makes B makes C makes D makes A, and A-B-C are
already in the big branching catalytic chain, but there's hardly any
input available for C to make D, so D has never been made in the
history of Earth. But one day some input for C to make D occurs, and C
immediately makes D, and there's plenty of input for D to make A, so
the chain is immediately closed, making a decent amount of A and hence
a large amount of B and hence a very large amount of C. But still
there's a shortage of input to make D, but there's such a vastly larger
amount of C sitting around waiting for it, that the moment some input
for making D occurs there's C nearby to gobble it, so none of it is
wasted. The more this cycle runs, the more C there is sitting around,
so the more efficient the cycle is at using any available input to make
D before that input randomly breaks up or gets consumed by some other
branch of the catalytic tree. So on a relatively short time span, the
quantity of A,B,C,D increases dramatically, most especially the amount
of C. Whereas before the cycle was closed, there were only a few
molecules of C in the whole ocean, hence only a few locales where
there's even one molecule of C nearby, and none at all of D, now there
could be billions of molecules of C, each one waiting for input to make
D, and these molecules of C would be drifting around to different
locales to in effect cover the globe. Now whenever, whereever, input
for C-making-D occurs, it'll be used for that purpose rather than
wasted. Perhaps after a while there'll be large quantities of C in
every locale, and this one catalytic loop will dominate the world's
catalytic chemistry.
 >>
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