Text 399, 437 rader
Skriven 2004-10-18 22:15:00 av Erwin Moller (1:278/230)
Ärende: Re: No Grace Period for M
=================================


TomHendricks474 wrote:

>>Hi Tom,
> And Hi to you.
> 
>>> There is no grace period on metabolism in the origin.
>>> 
>>> Some scenarios suggest that first came a first
>>> replicator - then followed a grace period where
>>> natural selection allowed this first replicator to
>>> develop a metabolism system to power itself!
>>> 
>>>  I ask what energy source was there to develop the
>>> metabolism system during that grace period? And how
>>> is it that that first replicator was in no way
>>> harmed or destroyed by the environment.
>>> It just couldn't happen.
>>
>>But it did.
> 
> Yes it did because there was constant and cyclical energy
> impute from the sun - a heat cycle that was constant enough to adapt to
> but variable enough to produce variants to allow for selection.

Well... yes of course.
Is anybody disputing that?

> Let's turn things around. Take out the sun - tell me
> how that would lead to life. I coudn't.
> We have taken the heat cycle for granted. I think life
> is a reaction to a heat cycle and  life is just that which best adapts to
> the heat cycle (and later other adaptations when that prime survival need
> is solved)

I don't expect any life without the sun (or other source of energy).
Again: I don't think anybody is disputing that.

> 
> 
>>Maybe not in the way that those theories you refer to describe, but it
>>did. I don't expect we will ever find out, with reasonable certainty, what
>>happened during the very origins of life.
> 
> I think we will and soon. But not if you are looking
> for a fluke replicator out of thin air. IF you  accept
> that life is that which best survives a heat cycle at the time of the
> origin - then recreating the exact conditions of that heat cycle,
> atmosphere, earth spin, tides, etc. will recreat the origin.. We are so
> close I can almost taste it IMO.

Well... what gives you that certainty?
What if the chances for 'sponanious creation' of selfreplicating molecules 
is extremely small, even under the 'right' conditions?
What if you need to run an experient on a planeary scale for 500.000.000 
years to have a chance of 1% to create a selfreplicating molecule?
I just don't know the numbers.
I think nobody knows.

What we actually need are more observations to get away from our n=1 
'experiment'. ;-)

Untill then I expect it is really hard to do any statistical feasably 
predictions on the matter. :-/



>>
>>Your point that any replicating machinery needs energy to run, is of
>>course true.
>>Replicating complex molecules reduces local enthropy, so costs energy to
>>achieve.
>>You wrote:
>>> Some scenarios suggest that first came a first
>>> replicator - then followed a grace period where
>>> natural selection allowed this first replicator to
>>> develop a metabolism system to power itself!
>>
>>IMHO:
>>I expect that the spot where this first happened had a good environment
>>with
>>energy in the 'right' form available to the first replicating molecules.
> 
> Oh please don't expet or accept or take anything for
> granted.

Erm....
Some things are just not really suitable for controlled experiments.
Like the origin of life.
Or the beginning of the universe.
Not everything can be reduced to a labcontrolled experiment.
Shame, but that's just it.

That aside, lets look at your argument:

> Let's make it not a fluke but a sure thing -
> Let's say
> 1. the sun powered all prebiotic processes.

Sorry, bad assumption. We already know of lifeforms living on 
Sulfer-energycycle deep down the sea where the sun is not delivering 
energy. The sulfer is delevering energy, no photosyntesis.

I think it is just a safer bet to say that energy in some form is needed. It 
can be electromagnectic, or chemical or maybe even something else.

> 2. when the sun began to waned or cool, the prebiotic
> processes that switched to alt forms of energy were the only that survived
> that environment.

ok.

> Thus order is everything.
> 1. 'sun selection.

What do you mean by sunselection?
Do you mean that if our planet was in the outer egions of a red giant, life 
would have a really hard time?

> 2. chemical selection when sun cooled

This means that on the surface of the planet some molecules can only exist 
when the temperature doesn't exceed certain values, right?
Or do I miss your point?

> 3. natural selection when chemical selection produced the first
> replicator. Now nothing is a fluke or a dream or a perchance.
> It's clear and obvious.

Is it?
I don't agree.

I DO agree with you that the circumstances must meet certain criteria, like 
restaints on the temperature. Complex molecules fall appart at high 
temperature.
That far I agree.

The problem is with the chemical beginning of life.

The bottomline is that nor you, nor me, nor anybody can tell how things 
evolved in the very beginning.
What are the chances of creating a self-replication molecule (or a set of 
selfreplicating molecules)?
How will you estimate a reasonable chance for that to happen with our 
current understanding?
We don't even know a lot of selfreplicating systems. We know of our own 
DNA/RNA replicating system, which needs a whole bunch of supporting 
molecules to deliver that trick.
So how did that start?
I don't believe the all the molecules were just there by a fluke chance, so 
I really expect a lot of steps inbetween.


> The problem I see is that most still subconsciously cherish the 'life is
> independent and special" falllacy and instead of a creationist moment
> they've barely switched to a first replicator springing out of thin air
> moment. Both are wrong. Dumb that paradigm. Look at the environment as it
> was. Don't try to anticipate life as something to fulfill a future event,
> and it all becomes much clearer IMO.

I am not doing any of these things, and I don't know of any respectable 
scientist who does.

You do not know how much life there is in the universe.
You don't know how big the chances were that selfreplication started.
You do not need a creationist-like argument to assume that it 'somehow' 
started.

In science it is 100% ok to say: I don't know that (yet!).

You wrote: "Don't try to anticipate life as something to fulfill a future 
event, and it all becomes much clearer IMO."

Agree. But again: Who is doing/claiming that?


>>
>>eg: a popular energycarrier nowadays in our cells is ATP.
>>When it looses a Phosphate (ATP--> ADP) energy is available.
>>I expect
> 
> Don't expect or postulate - prove.

You want me to prove that energy-rich molecules were available on spot where 
the first life (selfreplicating molecules) arose ??

The only 'real' proof is timetravel, which I regrettably cannot offer you.

But I can make it plausible, I think.
If you look at the behaviour of atoms, you'll see that they have this 
tendency to react with each other in such a way that they end up with 
minimal energy.
This is why water doesn't fall appart in H2 and O2 (a lot) at our current 
surfacetemperature.
In the H2O form the system released most energy. This is called lowest 
energy state and that is where most molecules head to.
You need extra energy to create molecules that are contain atoms not 
combined in their lowest energystate.

That is why I postulated that it is likely that the first selfreplicating 
molecules were in an energyrich environment. That makes is many/many times 
more likely to create the complex molecules capable of selfreplication.

Futhermore: This energy has to be available in a form suitable for those 
molecules of course.

I only took ATP as an example, I have no reason to expect any certain 
molecules on that first-life spot. 
Maybe a good physisist can make some educated guesses, I cannot.


> 
>  that on the spot where the first replicating molecules where
>>forming, the environment contained similar energy-rich molecules.
>>Most probably NOT ATP of course, but just energyrich molecules ready to
>>
>>react and making their energy available to the first replicating
>>molecules.
> 
> You still are depending on an order that seems wrong to
> me.

Ok, I hope I can explain that a little futher.
For clearity: I am NOT telling you how-it-is, I am trying to understand your 
point, ok? :-)

> 1. first replicator pops up 

Yup.

> 2. It has a grace period that is
> unexplainable in any scientific rational where it is not destroyed in a
> hadean time period.

This Hedean period was not one of the friendliest in Earths history.
But why is it impossible to survive this period?
If our first molecule replicates faster than it is destoyed (by 
heat/radiation/etc) it will be there.

But maybe you should explain more about this 'grace-period'.
Or point me to some source. I'll be happy to read some (online preferably) 
more about that.
Because I don't understand why you need a grace-period to explain the 
origins of selfreplicaing molecules.

> 3. Then sometime out of this fluke  vacumn it evolves metabolism (which 
> we note it didn't have before that so it was powered on magic dust?)
> I'm being sarcastic to prove the fallacy of the grace period - and to
> reset the order of events.

Ok, sarcasm is ok.
But I still need more info on this grace-period.
Maybe we totally agree. :-)
I just don't know anything about the theories behind it!


> 
> I do believe ATP or phosphate rich compounds were key in the change from
> Sun power to chemical power. I do believe that wherever the phosphate rich
> bonds were, the prebiotic nucleotides and peptides would prosper - thus I
> believe phosphate rich bonds were probably the glue that connected the
> info nucleotides with the protein world .
> But that is another chapter. And a later chapter.

Ok.

>>
>>In that way the molecules were trapped to that location.
>>Drifting away too far from the energydelivering molecules would mean that
>>
>>they loose their energysuply and 'die' (stops replicating).
>>
>>That situation (replicating molecules in a natural environment that
>>contains
>>
>>energyrich molecules usable for the first replicating molecules) can be
>>
>>called stable (for some time anyway).
> 
> That is way too iffy and improbable. See above.

No, I am not claiming too much.
I am only claiming that these first selfreplicating molecules needed an 
energysource, and when they are denied that source, they will stop 
replicating. 
Analogy: If I deny you cells ATP, they are in trouble.


>>
>>>From here on you can imagine that evolution favored those molecules that
>>
>>were able to create their own environment, by the use of membranes to
>>create an interior with the right mixes of needed molecules.
> 
> But here is that anthropomorphism raising its human
> head.  Life did not emerge to create its own environment.

Indeed.
Life did not emerge to do ANYTHING.
It just emerged.
And any change these first molecules had themselfs on their environment 
affected themselfs, and so their own succes.

I don't need any 'direction' or 'plan' to explain the fact that the first 
sets of selfreplicating molecules could modify their own environment.

> EVERY aspect of
> selection is adaptation to the environment.
> EVERY aspect of pre-origin was to adapt to the environment.
> How can any change that makes it less
> adaptable to the environment be selected IN that
> environment?

It cannot.
Or more accurate: The chances for succes are the key-factor. Succes as in: 
Making the most selfreplicating molecules.

> Thus being independent of the environment would never be selected during
> any period of this origin time.

independent is a word I wouldn't choose.
It is not all black-and-white.

What about a set of molecules that can self replicate that 'adjust' their 
environment to suit it needs better?
You don't need a plan for it. Just the simple fact that a certain chemical 
action makes the local environment better suited will be favored.
Do you agree?
I am not talking highly developed membranes with receptors here, but just 
basic stuff. 

> (Perhaps later  - 4 billion years later - as selfish
> genes - but that too is a much much later story.)

Selection takes place from the very first moment of self replicating.

The 'invention' of genes is a very logical next step (from my current 
perspective), but I have no clue how difficult/likely that 'invention' will 
be.
No doubt it is extremely usefull, but how likely is it to develop in the 
first place?
I have no clue.


>>
>>How this happens is of course all speculation, but I think you can safely
>>
>>say that the first replicating molecules had a great environment for that
>>
>>purpose,
> 
> I dont' agree and would ask for more proof or studies
> or more specific reasons backed up by studies etc.


You need studies for the the argument that the first replicating molecules 
had a great environment to come into existance?
That is self evident.
If they had a lesser favorable environment, the chances for them to come in 
existance were smaller. :-)
I am not claiming anything outrageous here...

Example: The chances for selfreplicating molecules to develop for the first 
time in the center of the sun is smaller than on Earth.
That is quite obvious of course. Too hot for stable molecules.

But again: The chances for selfreplicating molecules to develop for the 
first time at 5 degrees Kelvin is rather small too. Why? Not too much 
chemical activity at such a temperature.

Etc. etc.

I don't think you need a published paper to agree to the statement that the 
first selfreplicating molecules had a (relative) favorable environment for 
them to develop. 

Of course there are a lot of uncertainties, i know that.
What I call favorable for Earth to develop our 'kind of selfreplication' 
could be very unfavorable on another planet where something completely 
different gave rise to selfreplicating molecules.

The question is: What was a favorable environment on Earth to develop our 
string of live?


Kind Regards,
Erwin Moller

PS: Tom, can you give me a few pointers on this grace-period? Maybe I 
understand your point(s) better after reading them. As far as my current 
knowledge goes, I don't see the use of this grace-period to develop 
metabolism.


> 
> 
>  and later on developed/evolved to systems with their own energy
>>
>>machinery, allowing them to leave the original spot, venturing into other,
>>
>>less favorable, environments.
>>
>>In that way replication came first, energy-machinery (storing/releasing)
>>
>>later.
>>
>>Just my 2 cents.
>>
>>Regards,
>>Erwin Moller
>>
>>
>>> 
>>> In other words you need a time machine to take
>>> the evolved metabolism system back to when it
>>> was needed after the first replicator began
>>> evolving to the metabolism system that was needed
>>> to evolve the first metabolism system, etc! HUH???
>>> 
>>> Comment?
>>> Tom Hendricks,  Musea zine ed.
>>> http://musea.digitalchainsaw.com"
>>> 
>>> Musea GUARANTEES every musician, painter, writer, etc.
>>> a REVIEW - a tough review - a fair review.
>>> 
>>> Contact me for our policy. Samples:
>>> http://musea.digitalchainsaw.com/reviews1.html
>>
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