Abiogenesis chicken-and-egg problem

[lesliedellow]

Darwinism has always been inclusive of living and non-living history, going back to and including the Big Bang:

That is simply wrong as a matter of history. Darwin was dead before Lemaitre was even born.

 

[mark kennedy]

That is simply wrong as a matter of history. Darwin was dead before Lemaitre was even born.

That's hyperbole, this is the quote I was referring to:

He (Lamarck) first did the eminent service of arousing attention to the probability of all change in the organic, as well as in the inorganic world, being the result of law, and not of miraculous interposition. (Darwin, On the Origin of Species).​

Darwin wouldn't have called it the Big Bang but he assumed exclusively naturalistic causes for everything in the organic and inorganic world. That doesn't leave much out and includes all history.

Have a nice day
Mark

 

[SkyWriting]

I'd like to throw out an idea and get some thoughts on it.

It appears to me that one of the big problems with abiogenesis theory is a kind of chicken-and-egg problem.

DNA, by itself, doesn't do anything; it's a memory store that is acted upon by other chemicals. Where do those chemicals come from? They're manufactured in the cell by processes that read the DNA to get their specifications.

So which came first, the DNA or the chemicals that act upon them? If the DNA came first, nothing happens. But if those other chemicals came first, they can't reproduce because their specifications aren't stored anywhere.

So the DNA just happens to contain the very specifications of the chemicals that act upon it. It strikes me as a kind of chicken-and-egg conundrum, taken down to the cellular level.

I can't see such a system ever coming together randomly.

Any thoughts? Am I off-base here?

You are correct. I constantly ask for the scientific principal
that supports the "push-for-life" in nature.

None seems to exist. The idea is alive, but groundless.

 

[Coolant]

It turns out that RNA (like one side of DNA's double helix) can do just that. It makes sense then that an RNA heredity system could function, and then later, and RNA strand and it's complement could join to make a DNA system, which would work then because the catalysts are already around, plus it would benefit from the complintary base-pairing ability of DNA.
Papias

You did not bother to mention that RNA is too fragile to survive in a hostile environment, not to mention there are many other functions of DNA that RNA cannot do. Plus, there is no evidence now or in the past that RNA evolved into DNA...unless you can link a scientific peer-reviewed paper that shows how?

 

[mark kennedy]

RNA World a 'popular fantasy'

You did not bother to mention that RNA is too fragile to survive in a hostile environment, not to mention there are many other functions of DNA that RNA cannot do. Plus, there is no evidence now or in the past that RNA evolved into DNA...unless you can link a scientific peer-reviewed paper that shows how?

The RNA world theory like anything related to abiogenesis generally comes down to speculation. However, don't think for a second that the RNA first scenario is somehow universally accepted and there is really nothing close to a conclusive proof:

From a biosynthetic – as well as, arguably, evolutionary – perspective, DNA is a modified RNA, and so the chicken-and-egg dilemma of “which came first?” boils down to a choice between RNA and protein.
​

Well of course there are major objections from a scientific perspective:

Objections have been raised to the RNA world hypothesis:

(i) RNA is too complex a molecule to have arisen prebiotically;
(ii) RNA is inherently unstable;
(iii) catalysis is a relatively rare property of long RNA sequences only; and
(iv) the catalytic repertoire of RNA is too limited.​

far too long a sequence to have arisen through any conceivable process of random assembly. And typically 10,000,000,000,000-1,000,000,000,000,000 randomized RNA molecules…​

“I, for one, have never subscribed to this view of the origin of life, and I am by no means alone. The RNA world hypothesis is driven almost entirely by the flow of data from very high technology combinatorial libraries, whose relationship to the prebiotic world is anything but worthy of “unanimous support”. There are several serious problems associated with it, and I view it as little more than a popular fantasy” (Primordial soup or vinaigrette: did the RNA world evolve at acidic pH? Biol Direct. 2012)

(The RNA world hypothesis: the worst theory of the early evolution of life (except for all the others). Biol Direct. 2012)
​

Creationists have come up with probability arguments against abiogenesis before but then we do it it's psuedo-science or arguments from incredulity. Now there is one from peer reviewed scientific literature, not unlike one Creationists have been making for years.

From the opening line of the conclusion:

I have argued that the RNA world hypothesis, while certainly imperfect, is the best model we currently have for the early evolution of life. (Biol Direct. 2012)
​

The best explanation is the worst possible except for all the others. They make it so easy to be a Creationist.

Step from atoms to life could be:

1. atoms form simple molecules like NH3, CO2 (shown to happen)
2. These form organic precursors like amino acids (shown to happen)
3. These form more complicated peptide chains (shown to happen)
4. Some peptide chains are catalysts for their own formation - copying (shown to happen)
5. Some of these encode information (shown to happen)
6. Some form with sufficiently low copy errors (not yet shown to happen)
7. A copier with decent, but imperfect copying undergoes selection (shown to happen)
8. Complexity increases from there, leading to an RNA system (not yet shown to happen)
9. An RNA system, through failed separation, leads to a DNA system (not yet shown to happen)
10. A DNA system undergoes selection (shown to happen)
11. this is life as we know it.

I have always loved this topic because that comes with a statistical probability argument that is simply untenable. I just wish they would do a probablity argument for human brain related genes evolving from that of apes.

Grace and peace,
Mark

 

[pat34lee]

no self respecting Darwinian would dare admit a miracle, especially creation. Even those who profess to be Christian.

True, even when they are proposing even more miracles than the bible does. From the big bang, to stellar evolution, to planetary evolution, to abiogenesis, to every increase in information and complexity against all odds and every pertinent natural law. Not to mention a universe where we are perfectly placed to grow, learn and reach our potential.

 

[Armoured]

I'd like to throw out an idea and get some thoughts on it.

It appears to me that one of the big problems with abiogenesis theory is a kind of chicken-and-egg problem.

DNA, by itself, doesn't do anything; it's a memory store that is acted upon by other chemicals. Where do those chemicals come from? They're manufactured in the cell by processes that read the DNA to get their specifications.

So which came first, the DNA or the chemicals that act upon them? If the DNA came first, nothing happens. But if those other chemicals came first, they can't reproduce because their specifications aren't stored anywhere.

So the DNA just happens to contain the very specifications of the chemicals that act upon it. It strikes me as a kind of chicken-and-egg conundrum, taken down to the cellular level.

I can't see such a system ever coming together randomly.

Any thoughts? Am I off-base here?

Yep. You are off base. You should look up RNA and Spiegelman's Monster for starters.

 

[Armoured]

Not to mention a universe where we are perfectly placed to grow, learn and reach our potential.

"Look at this hole made perfectly my shape, just for me to fit in, it's proof of God", said the puddle.

 

[pat34lee]

DNA and rNA as building blocks are easy enough to discount, but even before that point, the problem is proteins. In order to be useful, they must be folded in just the right way, which does not happen by accident.

 

[mark kennedy]

True, even when they are proposing even more miracles than the bible does. From the big bang, to stellar evolution, to planetary evolution, to abiogenesis, to every increase in information and complexity against all odds and every pertinent natural law. Not to mention a universe where we are perfectly placed to grow, learn and reach our potential.

True, even when they are proposing even more miracles than the bible does. From the big bang, to stellar evolution, to planetary evolution, to abiogenesis, to every increase in information and complexity against all odds and every pertinent natural law. Not to mention a universe where we are perfectly placed to grow, learn and reach our potential.

True enough but I would mention that to date genetics has developed two scientific laws of nature reflecting meiosis and mitosis. Life procedes from life in nature which leaves abiogenesis in a highly speculative catagory of theoretical biochemistry. Perhaps some would infere miralles beyond the range of biblical revelation, there is sound reasn to believe the sun, moon and state were greater before creation week for instante.

 

[Armoured]

DNA and rNA as building blocks are easy enough to discount, but even before that point, the problem is proteins. In order to be useful, they must be folded in just the right way, which does not happen by accident.

You're assuming the first proteins needed to be as complex as modern proteins to be functional. In a prebiotic environment without competition, proteins wouldn't need to be as competetive as modern ones.

 

[pat34lee]

"Look at this hole made perfectly my shape, just for me to fit in, it's proof of God", said the puddle.

More like the very universe were made to promote our existence. From temperature, to free water, to light and darkness alternating, to the ocean tides, the moon, the exact gravity, protection from stray solar waves and radiation... any criteria you could think of, and every one you can't.

 

[Armoured]

More like the very universe were made to promote our existence. From temperature, to free water, to light and darkness alternating, to the ocean tides, the moon, the exact gravity, protection from stray solar waves and radiation... any criteria you could think of, and every one you can't.

We evolved to fit the universe. If the parameters of the universe were different, we'd have evolved to fit them. Anthropic principle - Wikipedia

 

[pat34lee]

You're assuming the first proteins needed to be as complex as modern proteins to be functional. In a prebiotic environment without competition, proteins wouldn't need to be as competetive as modern ones.

There is no way to tell if improperly proteins would combine at all, much less successfully. And even the least complex rNA or DNA has dozens of proteins.

 

[pat34lee]

We evolved to fit the universe. If the parameters of the universe were different, we'd have evolved to fit them. Anthropic principle - Wikipedia

That is wishful thinking, not science.

 

[Armoured]

There is no way to tell if improperly proteins would combine at all, much less successfully. And even the least complex rNA or DNA has dozens of proteins.

Why is there "no way to tell"? What's wrong with experiment?

 

[Armoured]

That is wishful thinking, not science.

You didn't read the article then.

 

[Papias]

You did not bother to mention that RNA is too fragile to survive in a hostile environment,

What exactly do you mean by "hostile environment"? Of course it can't exist in today's environment, when amoebas, enzymes, etc would destroy it - but they didn't exist then like they do today. That's like saying "no one could have sold a black and white tv in 1955, because who would buy a black and white tv instead of just getting an ipod!"

, not to mention there are many other functions of DNA that RNA cannot do.

what, specificially, are you talking about? Of course it need not do exactly everything DNA can do - it only need to be able to replicate.

Plus, there is no evidence now or in the past that RNA evolved into DNA...unless you can link a scientific peer-reviewed paper that shows how?

That's pretty well explained here. Origin and Evolution of DNA and DNA Replication Machineries - Madame Curie Bioscience Database - NCBI Bookshelf

In Christ -

Papias

 

[mark kennedy]

There is no way to tell if improperly proteins would combine at all, much less successfully. And even the least complex rNA or DNA has dozens of proteins.

The appeal of RNA is that it can he reduced to 400 nucleotides and sone change. Getting a protein peptide chain is vastly more complicated. The problem with RNA is its very vulnerable outside living systems, no catalysts and no power source.

The way RNA is translated into a protein is it goes into a ribosome that turns it into the three diminsional form. There's just no way of RNA doing it on there own in a highly acidic enviroment by itself.

 

[mark kennedy]

What exactly do you mean by "hostile environment"? Of course it can't exist in today's environment, when amoebas, enzymes, etc would destroy it - but they didn't exist then like they do today. That's like saying "no one could have sold a black and white tv in 1955, because who would buy a black and white tv instead of just getting an ipod!"

Put simply the prebiotic soup would have had too high of a PH for the RNA to have survived. These nucleotides have a low survivablity rate on their own anyway. The latest details I'm getting is that an RNA world would have to maintain a mean temperature of about 60 degrees. So much for LUCA surviving in superheated underwater vents:

we have suggested that the primordial ‘soup’ may have been more like vinaigrette, while Hanczyc has drawn a comparison with mayonnaise, with its emulsified mixture of oil in water (in light of these, could there be potential for food science to provide insights for origin of life studies?). (The RNA world hypothesis: the worst theory of the early evolution of life (except for all the others). Biol Direct. 2012)​

what, specificially, are you talking about? Of course it need not do exactly everything DNA can do - it only need to be able to replicate.

Which requires a the replicative polymerase and RNA and:

catalysis is a relatively rare property of long RNA sequences only; and (iv) the catalytic repertoire of RNA is too limited. (The RNA world hypothesis: the worst theory of the early evolution of life (except for all the others). Biol Direct. 2012)​

Then getting to the point of DNA, amino acid sequences, then at least 100 amino acid long protein all left-handed.

That's pretty well explained here. Origin and Evolution of DNA and DNA Replication Machineries - Madame Curie Bioscience Database - NCBI Bookshelf)

What it is, is recapitulation, just describing how living systems function and describing that as if it were history. They are suggesting a number of hypothesis, one that presupposes a viral DNA with replication mechanisms incorportated:

If DNA and DNA replication proteins originated in viruses, one can imagine that DNA replication mechanisms have been transferred from viruses to cells. (Origin and Evolution of DNA and DNA Replication Machineries. NCBI)​

The smallest virus known to science is 1.7 kilobytes and only has one open reading frame:

The genome size of RNA viruses is generally shorter than that of DNA viruses and ranges approximately from 2 to 31 kb. The smallest RNA virus identified to date is the human hepatitis D virus (HDV) which is about 1.7 kb in size and contains only one ORF (Hepatitis delta virus BioNumber Details Page)
​

Darwin's old trick of recapitulation doesn't give us any verifiable proof of a self organizing RNA viral origin of LUCA, it's based on supposition are a priori assumptions:

If DNA actually appeared in the RNA world, it was a priori possible to imagine that formation of the four dNTPs from the four rNTPs was initially performed by ribozymes. Most scientists, who consider that the reduction of ribose cannot be accomplished by an RNA enzyme, now reject this hypothesis. (Origin and Evolution of DNA and DNA Replication Machineries. NCBI)
​

The problems with the RNA World are legion, the high points are giving rise to protein coevolution which is even more problematic:

RNA is too complex a molecule to have arisen prebiotically
RNA is inherently unstable
Catalysis is a relatively rare property of long RNA sequences only
The catalytic repertoire of RNA is too limited
​

(See Discussion: The RNA world hypothesis: the worst theory of the early evolution of life except for all the others. Biol Direct. 2012)
​

Which sets up my favorite line from the paper:

Take, for example, Charles Kurland in his 2010 piece in Bioessays, which is utterly scathing of the RNA world hypothesis and its fellow travelers: “The RNA world hypothesis has been reduced by ritual abuse to something like a creationist mantra”. (Biol Direct. 2012)
​

But of course it is, it's a slam dunk and you don't have to cite a single creationist to make the argument.

Grace and peace,
Mark