🚀 go-pugleaf

In article <1357@tdat.teradata.COM> swf@tdat.teradata.com (Stanley Friesen) writes:

 >|Au contraire!  Our ignorance about origin of life is profound, and
 >|very little progress has been made in dispelling it.  There is no
 >|really plausible model for the origin of life.  We're missing at least
 >|one, and possibly several, fundamental ideas.

 > Have you read Cairns-Smith's "Seven Clues to the Origin of Life"?
 > I consider that to be an extremely plausible model (though the best
 > reasons are not in that, now out-of-date, book).

Cairns-Smith's ideas are very imaginative, but are supported by almost
no evidence.  In particular, no one has ever demonstrated that clays
-- or any other crystals -- can propagate genetic information.  The
fact that such speculations are taken seriously shows how blocked the
field has become.

 > Also, one could argue, based on the usual defnitions of life, that the
 > recently produced self-replicatinf RNA molecule *is* alive, and thus
 > we *have* made life in the laboratory. (Of course the exact definition
 > of life in the boundry cases is decidedly difficult, so one could also
 > make a case that it is not alive).

Sure, we've made RNAs in the laboratory -- using purified, chiral
tri(?)phosphorylated nucleotides, which (correct me if I'm wrong)
are extracted from biological sources.  Prebiotic Miller-Urey type
experiments have not, to my knowledge, ever produced nucleotides, nor
have they produced anything but racemic mixtures of mostly
biologically irrelevant molecules.  The monomers of RNA are
sufficiently complicated that it is quite implausible they could have
arisen without some prior evolution.

	Paul F. Dietz
	dietz@cs.rochester.edu