This doesn't address the fundamental problems. People like Leslie Orgel
have explained why metabolism first is a non-starter. He has argued on
the basis of the difficulties of getting to functional RNA, and more
recently people like Paul Davies have pointed out the fundamental nature
of this problem. My suggestion is not some new model, it simply makes
conventional models such as e.g. the protocell work better by putting
these in a micro-environment that itself has been forged in far from
equilibrium conditions. The micro-environments break the symmetry that
can steer the chemistry that takes place inside more coherently in one
or the other direction compared to whatever chemistry can go on in a
macroscopic environment.
Keep in mind that the simplest functional living organism is likely
going to be similar to a microbe, involving hundreds of thousands of
different enzymes that are then all necessary to make each other and
maintain and copy the organism. There thus exists a massive gap from
simple chemistry to the simplest self-reproducing lifeforms. The only
plausible solution is then a scenario where simpler systems that would
not function good enough to be able to reproduce with a multiplication
factor of larger than one, can reproduce with a multiplication factor
larger than 1 in a protected environment. But that environment must then
have features that would have to play the role of the more sophisticated
molecular machinery that makes the more advanced life forms work. Fixed
features on the inner surface area of a micro-environment can then work.
The effect such features have over the entire volume can be
non-negligible in a small system.
Saibal
On 07-07-2019 08:32, 'Brent Meeker' via Everything List wrote:
I think Nick Lane's metabolism-first theory, which he discusses in his
book "The Vital Question", is more plausible. There's good online
talk by Lane https://www.youtube.com/watch?v=PhPrirmk8F4.
Brent
On 7/6/2019 8:32 AM, smitra wrote:
https://arxiv.org/abs/1711.01945
A followup article which focuses more on the mathematical issues is
under construction, the key points are:
1) In interstellar space, simple organic compounds captured in small
ice grains were subject to UV radiation and occasional heating due to
incident cosmic rays (CR). This induced a bond percolation process
that led to large clusters of organic molecules on a time scale of
$\gtrsim 10^6$ years.
2) On a proto-planet, such clusters can merge into loosely bound
superclusters. The deep interior of such superclusters can provide for
chemical micro-environments in which conventional models of
abiogenesis driven by cold-warm cycles can be considered.
3) Rapid fluctuations in the chemical potentials of certain chemical
compounds that can penetrate the supercluster, will be damped down.
Long term gradual and periodic changes then dominate, allowing any
biochemical systems inside the superclusters to more easily evolve
toward exploiting the conditions in their micro-environments, compared
to a similar system in the outside environment.
4) As the supercluster breaks up, the system experiences more of the
shorter term fluctuations that has more of a random character. The
system can then evolve to adapt to these fluctuations, when doing so
right from the start might not have worked.
5) On a small fraction of the superclusters these processes led to
microbes capable of surviving in the outside environment.
6) Microbes were transferred to Earth via a collision of a
microbe-containing proto-planet with the Moon. Fragments containing
microbes resulting from the giant impact rained down on the Earth.
Saibal
On 06-07-2019 10:48, 'Cosmin Visan' via Everything List wrote:
https://www.youtube.com/watch?v=r4sP1E1Jd_Y [1]
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[2].
Links:
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[1]
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