I shouldn’t argue the “No organic nutrients whatsoever.” point too much—and indeed, I thought I deleted it from my comment pretty quickly. Yes, maybe everything organic was made from inorganic CO2 at the time of the first cells—but do we really know that with 70% confidence? No organic nutrients seems like quite a strong claim.
… maybe everything organic was made from inorganic CO2 at the time of the first cells—but do we really know that with 70% confidence?
Well, actually I think the carbon sources were more likely inorganic CO and inorganic HCN, with H2CO (formaldehyde) a possibility. “Organic”, in this claim, means having a C-C bond. And yes, I believe it with 70% confidence. Autotrophy came first. Heterotrophy came later.
No organic nutrients seems like quite a strong claim.
It is. It is the claim which forces a kind of intellectual honesty on the rest of your origin theory. You can’t just postulate that some needed chemical arrived on a handy comet or something. If you need a molecule, you must figure out the chemistry of how to make it from the materials already at hand. Wachtershauser didn’t suggests vents as the site of the origin simply because vents were new and “hot” at the time of his proposal. He did so because his chemical training told him that forming carbon-carbon bonds in high yields without enzymes requires a high-pressure high-temperature metal-catalyzed process like Fischer-Tropsch. And then he realized that vents provided an environment where this kind of chemistry could take place naturally.
I won’t argue with the “Autotrophy came first. Heterotrophy came later.” However, you were talking about the origin of cells here—and they “came later” too. Before there were cells there were very likely simpler “naked” replicators—including ones on mineral surfaces.
Surely though, this radically transforms your original claim:
“Organic”, in this claim, means having a C-C bond.
Surely that is not what “organic” normally means in this context! E.g. see:
If you say “organic nutrient molecules” and it actually turns out you mean only those with C-C bonds, your audience is very likely to get the wrong end of the stick.
Before there were cells there were likely simpler “naked” replicators.
I believe you are wrong if you are talking about replicating information-bearing molecules or crystals. 70% confidence.
Surely though, this radically transforms your claim …
Not really. My original claim didn’t even mention autotrophy. I added it as explanation of why Wachtershauser is so completely divergent from other ideas regarding the origin.
Contrary to your reference HCN is also considered inorganic, along with CO and CO2 and their hydrates. If you want to consider formaldehyde as an organic, and hence as a nutrient for a heterotroph, go ahead—I strongly doubt that it was the original carbon source in any case. 70% confidence.
Before there were cells there were likely simpler “naked” replicators.
I believe you are wrong if you are talking about replicating information-bearing molecules or crystals. 70% confidence.
Replication happens naturally, in crystal growth processes. Of course, that doesn’t prove that early mineral copying processes ultimately led to modern organisms, but it makes me pretty confident of my specific statement above—maybe 90% confidence—and most of the remaining probability mass comes from panspermia and cosmic evolution scenarios—where the origin of life takes place far, far away.
Replication happens naturally, in crystal growth processes. Of course, that doesn’t prove that early mineral copying processes ultimately led to modern organisms, but it makes me pretty confident of my specific statement above.
Ok, it is possible that there were information-bearing replicating crystals. Before organic forms of life. Totally irrelevant to LAWKI, but first. The only thing that makes me doubt that suggestion is that no one—including the abstract of the reference you provide—has given an example of an information-bearing replicating crystal. Good arguments for why that kind of thing might be possible, yes. But actual evidence of it happening somewhat naturally, no.
I’ve seen examples of information bearing crystals that repeat the same information layer-after-layer. And I’ve seen non-information-bearing crystals that actually do something comparable to reproduction (splitting, growth, splitting again). I’ve just never seen a paper where both were happening at the same time.
The clay theory is just not going to be taken seriously until someone has a population of clay “organisms” replicating away in a lab and then starts running long-term evolution experiments on them like Lenski is doing with bacteria.
I am puzzled by your terminology. Replication implies high-fidelity copying of information. That is what some crystals (e.g. barium ferrites) can do. It is an “information bearing replicating crystal”. So, what exactly are you asking for? and why are the polytypic layer structures in barium ferrites not it?
You ask for splitting. However, one of the key insights in this area is that you can have evolution-without splitting—via “vegetative reproduction”:
Not that splitting is terribly demanding. Make anything big enough and it will break up—if only under its own weight. The real issue is whether the split introduces mutations that lead to a meltdown. That is a potential problem for 1D crystals—but 2D ones don’t depend on splitting—and if there are splits there are still likely to be operational viable growth fronts after the split.
The clay theory is just not going to be taken seriously until someone has a population of clay “organisms” replicating away in a lab and then starts running long-term evolution experiments on them like Lenski is doing with bacteria.
No-one else can make life from primitive materials yet either—this requirement strikes against every OOL theory equally.
To recap, the main reason for thinking Crystalline Ancestry is true is because clay mineral crystals actually replicate patterns of reasonable size with high fidelity under plausible pre-biotic conditions (and this is the #1 requirement for any evolving system) - whereas no other pre-biotically plausible structure has been demonstrated to do so.
However, it’s a reasonable request to want to see evolution based on the theory in the lab. Growing many clays in the lab is terribly difficult—and often takes forever—but success there would be interesting. However, much of the existing work has been done with “found” natural clays. They seem to be a more obvious focus—in some respects.
I shouldn’t argue the “No organic nutrients whatsoever.” point too much—and indeed, I thought I deleted it from my comment pretty quickly. Yes, maybe everything organic was made from inorganic CO2 at the time of the first cells—but do we really know that with 70% confidence? No organic nutrients seems like quite a strong claim.
Well, actually I think the carbon sources were more likely inorganic CO and inorganic HCN, with H2CO (formaldehyde) a possibility. “Organic”, in this claim, means having a C-C bond. And yes, I believe it with 70% confidence. Autotrophy came first. Heterotrophy came later.
It is. It is the claim which forces a kind of intellectual honesty on the rest of your origin theory. You can’t just postulate that some needed chemical arrived on a handy comet or something. If you need a molecule, you must figure out the chemistry of how to make it from the materials already at hand. Wachtershauser didn’t suggests vents as the site of the origin simply because vents were new and “hot” at the time of his proposal. He did so because his chemical training told him that forming carbon-carbon bonds in high yields without enzymes requires a high-pressure high-temperature metal-catalyzed process like Fischer-Tropsch. And then he realized that vents provided an environment where this kind of chemistry could take place naturally.
I won’t argue with the “Autotrophy came first. Heterotrophy came later.” However, you were talking about the origin of cells here—and they “came later” too. Before there were cells there were very likely simpler “naked” replicators—including ones on mineral surfaces.
Surely though, this radically transforms your original claim:
Surely that is not what “organic” normally means in this context! E.g. see:
http://en.wiktionary.org/wiki/organic_compound
Formaldehyde is an organic compound.
If you say “organic nutrient molecules” and it actually turns out you mean only those with C-C bonds, your audience is very likely to get the wrong end of the stick.
I believe you are wrong if you are talking about replicating information-bearing molecules or crystals. 70% confidence.
Not really. My original claim didn’t even mention autotrophy. I added it as explanation of why Wachtershauser is so completely divergent from other ideas regarding the origin.
Contrary to your reference HCN is also considered inorganic, along with CO and CO2 and their hydrates. If you want to consider formaldehyde as an organic, and hence as a nutrient for a heterotroph, go ahead—I strongly doubt that it was the original carbon source in any case. 70% confidence.
Replication happens naturally, in crystal growth processes. Of course, that doesn’t prove that early mineral copying processes ultimately led to modern organisms, but it makes me pretty confident of my specific statement above—maybe 90% confidence—and most of the remaining probability mass comes from panspermia and cosmic evolution scenarios—where the origin of life takes place far, far away.
Ok, it is possible that there were information-bearing replicating crystals. Before organic forms of life. Totally irrelevant to LAWKI, but first. The only thing that makes me doubt that suggestion is that no one—including the abstract of the reference you provide—has given an example of an information-bearing replicating crystal. Good arguments for why that kind of thing might be possible, yes. But actual evidence of it happening somewhat naturally, no.
I’ve seen examples of information bearing crystals that repeat the same information layer-after-layer. And I’ve seen non-information-bearing crystals that actually do something comparable to reproduction (splitting, growth, splitting again). I’ve just never seen a paper where both were happening at the same time.
The clay theory is just not going to be taken seriously until someone has a population of clay “organisms” replicating away in a lab and then starts running long-term evolution experiments on them like Lenski is doing with bacteria.
I am puzzled by your terminology. Replication implies high-fidelity copying of information. That is what some crystals (e.g. barium ferrites) can do. It is an “information bearing replicating crystal”. So, what exactly are you asking for? and why are the polytypic layer structures in barium ferrites not it?
You ask for splitting. However, one of the key insights in this area is that you can have evolution-without splitting—via “vegetative reproduction”:
http://originoflife.net/vegetative_reproduction/
For some plant evolution, you don’t need splitting, only growth. Much the same is true for some “2D” crystals too.
Not that splitting is terribly demanding. Make anything big enough and it will break up—if only under its own weight. The real issue is whether the split introduces mutations that lead to a meltdown. That is a potential problem for 1D crystals—but 2D ones don’t depend on splitting—and if there are splits there are still likely to be operational viable growth fronts after the split.
No-one else can make life from primitive materials yet either—this requirement strikes against every OOL theory equally.
To recap, the main reason for thinking Crystalline Ancestry is true is because clay mineral crystals actually replicate patterns of reasonable size with high fidelity under plausible pre-biotic conditions (and this is the #1 requirement for any evolving system) - whereas no other pre-biotically plausible structure has been demonstrated to do so.
However, it’s a reasonable request to want to see evolution based on the theory in the lab. Growing many clays in the lab is terribly difficult—and often takes forever—but success there would be interesting. However, much of the existing work has been done with “found” natural clays. They seem to be a more obvious focus—in some respects.