Re: Logic Gives But One Choice On OOL. Can any find another?

in article fqeu0n$1565$1@xxxxxxxxxxxxxxxxxxx, Tom Hendricks at
tom-hendricks@xxxxxxx wrote on 3/2/08 11:09 AM:

On Feb 28, 12:49 pm, verulam <johnhewit...@xxxxxxxxx> wrote:
Tom,
OK, you feel the nucleotide problem can be solved but I do not agree.
I think nucleotides can only arise as part of an established
metabolism, which is a "metabolism first" viewpoint.

"Metabolism first' is a fluke chemical event. Now when metabolism pops up is
it immediately adapted to the environment, or is it destroyed in that
environment? if not adapted immediately, we need another fluke. That's two, -
you'll need about 10 more before your'e done. And one is enough to rule out
life.

Tom,

I would count myself in the metabolism-first camp, and I think you are
missing the point of this view. The emergence of a metabolism de novo is no
more of a fluke event than the emergence of a convection cell in the
atmosphere. You could argue that a convection cell is initially spawned by
a fluke puff of wind that entrains the emergence of a full blown dissipative
structure, but that would also miss the point. Like a convection cell, a
metabolism does thermodynamic work. The structure of a dissipative
metabolism is fueled by local gradients (e.g., macromolecular structures,
thermal gradients, and so on) and could be sparked by chaotic chemical
dynamics (analogous to a puff of wind sparking a convection cell). I
wouldn't call chemical dynamics a metabolisms until positive feedback loops
are established, which effectively sustain the structure of the metabolic
chemistry (again, analogous to positive feedback within a convection cell).

In other words, the metabolisms-first view envisions the prior existence of
a physical potential (e.g., a thermal and/or macromolecular gradient) that
pulled dynamic metabolic (chemical) structures into existence. This is
different from a fluke.

Cheers,

Guy



.

Relevant Pages

  • Re: Chain reactions and sparks in the origin of life
    ... a 'fluke' if it is the inevitable result of deterministic thermodynamic ... That means that your key event must either happen more than once which ... may be necessary for life. ... contemplate an original metabolism which is so impoverished ...
    (sci.bio.evolution)
  • Re: Chain reactions and sparks in the origin of life
    ... a 'fluke' if it is the inevitable result of deterministic thermodynamic ... The second sense is that the key event might be inevitable ... on some kinds of planets but practically impossible on most ... contemplate an original metabolism which is so impoverished ...
    (sci.bio.evolution)
  • Re: Logic Gives But One Choice On OOL. Can any find another?
    ... metabolism, which is a "metabolism first" viewpoint. ... if not adapted immediately, we need another fluke. ... because the underlying chaotic chemical dynamics are ... fire (new origins of life), because it is already being tapped by the ...
    (sci.bio.evolution)
  • Re: Logic Gives But One Choice On OOL. Can any find another?
    ... metabolism, which is a "metabolism first" viewpoint. ... it immediately adapted to the environment, or is it destroyed in that ... if not adapted immediately, we need another fluke. ... Do chemicals want to get to you - to metabolism, ...
    (sci.bio.evolution)
  • Re: Logic Gives But One Choice On OOL. Can any find another?
    ... metabolism, which is a "metabolism first" viewpoint. ... You could argue that a convection cell is initially spawned by ... By contrast Tom is, himself, assuming that nucleotides will simply pop ...
    (sci.bio.evolution)
Loading