Re: OOL X - The origin of the RNA world.

> From: Tim Tyler <tim@xxxxxxxxxxx>
> I figure during the "blister" stage there will be organic genes of
> some kind under the blisters, that manufacture themselves, and
> assemble the membrane.

Have you proposed a mechanism for the origin of the ancestors of those
genes such that they have a mechanism for evolving toward doing all
those things you ask of them?

> I.e. these organisms would manufacture lipids - not be based on them.

I agree, with the understanding that the phrase "based on" refers
strictly to the genome (the chemistry of the "immortal" data). The
organism as a whole would contain both the genome and various tools
made by the genome, the latter including the lipids.

> Lipids seem unsuitable as a basis for life - they are not good at
> template replication or supporting other methods of inheritance.

They are good at forming membranes that enclose replicators so that
group selection of the enclosed replicators is likely, which allows
evolution of altruistic genes. That may be regarded as supporting group
inheritance as opposed to every-replicator-for-himself inheritance.

> > That, as I have said many times, is my main problem with Cairns-Smith's
> > theory. It doesn't explain in enough plausible detail HOW natural
> > selection did it.

> It's an explanation for the *origin* of natural selection.
> It leaves off at the point where organisms have a few hundred bits of
> genome.

It's been a long time since I saw his theory, but it seemed to me that
the variety of different forms of clay crystals was nowhere near
diverse enough to support such a large information-full genome. Is my
impression mistaken? If so, is there a Web page that explains how such
a large variety is possible from a single environment of clay material?

> Once evolution takes off a staggering number of options and
> possibilities open up.

In the case of carbon-based polymeric genome, with incremental changes
to arbitrary positions along the sequence, I agree, there's enough
potential variety. But if there's only a limited total space of
possible combinations, as there seems to be with clay crystals, your
staggering number doesn't happen.

> IMO, the main problem with the origin of life is the puzzle of how
> the first organisms managed to overcome their error catastrophe.

I don't recall the term "error catastrophe" before. Please summarize
for me?

> Once life gets going, subsequent hurdles can be crossed with the help
> of natural selection, which can pull off all kinds of amazing feats.

It depends on your definition of "life". With "just barely life", i.e.
a single replicator with no built-in mechanism for evolution, your
conclusion doesn't follow. But with "fully-genomic
incrementally-evolving life", the conclusion does follow. That's why I
felt I needed to explain how a single replicator might yield
"fully-genomic incrementally-evolving life" before I considered my OOL
just-so story complete (a few months ago).

.

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