Freethought & Rationalism Archive

Indifference · 09-25-2002, 06:42 AM

I happened upon the clay crystal origins theory in one of the threads yesterday and decided to check it out... fascinating!

Anyway, I'm curious as to why it isn't taken seriously by most scientists. Most referencs I found simply wrote it off as speculation. But from what I can tell, it is simply unexplored.

Any insight is appreciated.

Thanks,

sam

Non-praying Mantis · 09-25-2002, 10:13 AM

Quote:

Originally posted by Indifference:
<strong>...clay crystal origins theory...

Anyway, I'm curious as to why it isn't taken seriously by most scientists....

...But from what I can tell, it is simply unexplored.
</strong>

Bingo! You answered your own question.

NPM

Doubting Didymus · 09-25-2002, 02:58 PM

The problem is, how are you going to explore it? capture, tag, and release the clay crystals? follow them around for a year or two?

The main barrier that I see with the clay crystal theory is that I can not envision a way for the crystals to progress to an RNA molecule.

RBH · 09-25-2002, 04:38 PM

DD wrote

Quote:

The main barrier that I see with the clay crystal theory is that I can not envision a way for the crystals to progress to an RNA molecule.

It's been years since I read "Seven Clues," but as I dimly recall it, the clay crystals don't themselves 'progress' to RNA. Rather, they serve as physical templates/substrates for the formation of complex organic molecules, to sort of get complex organics under way. After that, the organics are on their own.

RBH

Doubting Didymus · 09-25-2002, 05:33 PM

I know that, but I still can't find peace with it. Somehow, being a template for the right amino acids would have to be a selection advantage for the clay crystal, and while this is theoretically possible, I just cant get my (admittedly non-expert) head aroung the specifics.

Leslie Orgel summs up my own misgivings <a href="http://www.geocities.com/CapeCanaveral/Lab/2948/orgel.html" target="_blank">somewhere on this long-winded site</a> about RNA, and its progression toward self replication and then to biological states.

toward the bottom, he states RE cairns-smith:

Quote:

Some 30 years ago he proposed that the very first replicating system was inorganic. He envisaged irregularities in the structure of a clay - for example, an irregular distribution of cations (positively charged ions) - as the repository of genetic information. Replication would be achieved in this example if any given arrangement of the cations in a preformed layer of clay directed the synthesis of a new layer with an almost identical distribution of cations. Selection could be achieved if the distribution of cations in a layer determined how efficiently that layer would be copied. So far no one has tested this daring hypothesis in the laboratory. On theoretical grounds, however, it seems implausible. Structural irregularities in clay that were complicated enough to set the stage for the emergence of RNA probably would not be amenable to accurate self-replication.

I just can't see how surface irregularites that complex would 'help' the clay crystal. However, perhaps the clay crystals were templates for still simpler organic replicators, which left the clay behind before advancing to RNA. The question is then: what organic replicator is that simple?

09-25-2002, 06:42 AM	#1
Indifference Regular Member Join Date: Apr 2002 Location: Pennsylvania Posts: 165	Cairns-Smith I happened upon the clay crystal origins theory in one of the threads yesterday and decided to check it out... fascinating! Anyway, I'm curious as to why it isn't taken seriously by most scientists. Most referencs I found simply wrote it off as speculation. But from what I can tell, it is simply unexplored. Any insight is appreciated. Thanks, sam

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09-25-2002, 02:58 PM	#3
Doubting Didymus Veteran Member Join Date: Jul 2002 Location: East Coast. Australia. Posts: 5,455	The problem is, how are you going to explore it? capture, tag, and release the clay crystals? follow them around for a year or two? The main barrier that I see with the clay crystal theory is that I can not envision a way for the crystals to progress to an RNA molecule.

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