> Here's a paper that stresses a heat cycle component.
>
> Thermosynthesis as energy source for the RNA World:
> A model for the bioenergetics of the origin of life
> Anthonie W.J. Muller *
> Department of Geology, Washington State University, Pullman, WA
> 99164-2812, USA
> Received 10 May 2005; received in revised form 10 June 2005; accepted
> 10 June 2005
> Abstract
> The thermosynthesis concept, biological free energy gain from thermal
> cycling, is combined with the concept of the RNA
> World....
>
>
> Keywords: Binding change mechanism; Bioenergetics; Genetic code;
> Origin of life; RNA World; Thermosynthesis
> 1. Introduction
> The three types of energy sources used by today's
> organisms, fermentation, photosynthesis and respi-
> ration, are all complex and require many proteins.
> As a result none of these energy sources have been
> linked directly to the origin of life. A fourth energy
> source, 'thermosynthesis,' free energy gain from ther-
> mal cycling, is much simpler, and has therefore been
> put forward in a theoretical model for the emergence
> of the chemiosmotic machinery used by both photo-
> synthesis and respiration (Muller, 1985, 1993, 1995,
> 1996, 2003).
>
> (Does anyone know about Muller's work?)
Anthonie Muller has posted here several times over the
last decade or so (during the period when you (Tom) and
I have been active). His ideas (if I understand them) are
that a molecule (think of an enzyme) can extract useable
free energy from the environment if it is subjected to a
rather rapid thermal cycle. Unlike your ideas, which
assume a cycle once a day or so, Muller thinks that
the relevant cycles were more like once a minute or
so. You get a thermal cycle this fast if you are a molecule
which is circulating in a convection cell.
My own opinion is that this is would be an interesting
possible source of phosphorylation energy for a simple
protean organism, but it cannot explain the origin of that
organism. The kinds of enzyme-like molecules that would
be capable of tapping this kind of energy source could
only arise by natural selection - they could not preceed
natural selection.
> The postulated molecular heat engines
> produced the same ATP as contemporary ATP syn-
> thase, but with much less power (energy produced per
> unit time) because the enzyme turnover time equaled
> the long thermal cycle time of a convection cell...
Yep. Notice, by the way, that modern ATP synthase
doesn't require any kind of environmental cycle - all
it needs is a concentration, voltage, or pH gradient.
And it sure seems to me that such things are a lot
easier to find than cycles. And just as easy to use.
Life can arise in a steady-state situation - it just doesn't
need cycles.
