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ASTRO BOY
2013-Jul-30, 09:56 PM
Cracking how life arose on Earth may help clarify where else it might exist:


Russell's hypothesis proposes that the transition to life was brought about by a peculiar geophysical and geochemical process called serpentinization—a process that played out on and just beneath the surface of our very young planet's ocean floor in the "Hadean" epoch more than 4 billion years ago.



Thus, according to Russell's hypothesis, first life didn't have to make any of this stuff for itself. It was all a free gift of geochemistry on a wet, rocky, and tectonically-active planet.


Read more at: http://phys.org/news/2013-07-life-arose-earth.html#jCp

Selfsim
2013-Jul-30, 10:20 PM
The possibility that life may have co-opted the extant geochemistry of serpentization on early Earth, decouples the geochemical process from the present day (and past) cheomtrophic one. There is no implication that if serpentization exists on some other 'world', life will also evolve to make use of it.

ASTRO BOY
2013-Jul-30, 10:33 PM
Another supplementary article......

A coherent pathway which starts from no more than rocks, water and carbon dioxide and leads to the emergence of the strange bio-energetic properties of living cells, has been traced for the first time in a major hypothesis paper in Cell this week.


"Life is, in effect, a side-reaction of an energy-harnessing reaction. Living organisms require vast amounts of energy to go on living," said Nick Lane



Read more at: http://phys.org/news/2012-12-life-emerged-cell-membrane-bioenergetics.html#jCp

publiusr
2013-Aug-03, 07:41 PM
I wonder if vorticity may have a role...

Colin Robinson
2013-Aug-21, 02:52 AM
The possibility that life may have co-opted the extant geochemistry of serpentization on early Earth, decouples the geochemical process from the present day (and past) cheomtrophic one. There is no implication that if serpentization exists on some other 'world', life will also evolve to make use of it.

The hypothesis in the article cited in the OP is not that serpentinization wherever it happens will lead to life. It is serpentinization at the bottom of a mildly acidic ocean, creating rising plumes of alkaline droplets with oily membranes. This seems like a reasonable explanation for the origin of the cell wall, which is a key feature of life on Earth.

In saying the hypothesis seems reasonable, I do not mean to say it is certain. It may well be that further work will falsify the hypothesis.

I am not quite sure what you mean by the "the possibility that life may have co-opted". Are you suggesting a life-form without a cell-wall, i.e. something like a virus, but more independent, which came into being via some other process, before it began to make use of the chemistries and the membranes described?

Selfsim
2013-Aug-21, 07:13 AM
... I am not quite sure what you mean by the "the possibility that life may have co-opted". Are you suggesting a life-form without a cell-wall, i.e. something like a virus, but more independent, which came into being via some other process, before it began to make use of the chemistries and the membranes described?The way we view a cell, even a simple precusor one, still involves many parts, themselves, involving many diverse functions. When we talk about early 'life', I think we have to recognise that some of these early closer-to-geochemical functions and processes, whilst not necessarily fitting into our modern-day definitions of 'life', almost certainly formed critical parts of some process which led to more life-like functions. If complexity was also building, ultimately leading towards self-replication, then any combinations of these pre-cursor functions might be able to be thought of as being equiprobable and maybe, interdependent: It was complex, y'know(?)

Somewhere in all of this, an as yet undistinguished (for us) set of physical laws was emerging.
Its the nature of that set of laws which will determine the 'knowability', (or otherwise) for us, of life's emergence.

Pretty wobbly stuff, (I know), but I hope you might also be able to see that pursuing the question of which came first .. the chicken or the egg (ie: the cell wall or 'engine'), may not be particularly fruitful .. science has been at it seemingly forever .. and the question may not matter at the end of the day.

Githyanki
2013-Aug-22, 02:32 AM
I'd love to believe that life is a naturally occurring process in which all planets experience given the right conditions. However, the process should be occurring today as well and we're not seeing new life, "Emerge".

Colin Robinson
2013-Aug-22, 09:08 AM
I'd love to believe that life is a naturally occurring process in which all planets experience given the right conditions. However, the process should be occurring today as well

Not necessarily.

There are several factors which work against a new form of life emerging on Earth today.

1.The amount of free oxygen (O2) in the atmosphere (and dissolved in the ocean) tends to stop complex organics from forming spontaneously.

2.If any new complex organics did emerge (e.g. in localized environments with lower levels of O2), wouldn't they would be more likely to get eaten by existing life-forms than to self-organize into something new?

3.According to thermodynamic models, the beginning of life involved a net increase of entropy: a discharge of particular forms of pent-up chemical energy. Once a channel was there for those forms of chemical energy to be discharged, the energy could no longer accumulate to the point of creating some new channel.

One thing these 3 factors have in common, is they are all results of life being here in the first place.


and we're not seeing new life, "Emerge".

Life always changes its environment. And not necessarily in ways which would make other life more likely to appear.

BigDon
2013-Aug-24, 08:43 PM
Where I live we have a lot of serpentine pushed up to accessible levels. As a child I found large beautiful green and blue pieces of both soap stone and serpentine in chucks a foot across, but I was advised by my seventh grade science teacher, (a paleontologist when he wasn't teaching) against doing that as a lot of the pieces had veins of native asbestos in them.

A local highway off ramp project was delayed more than a year because they ran into a large deposit of asbestos that had to be dealt with before the project could continue. They took very serious precautions when they removed it too. The site was always covered despite mining operations. By guys in space suits. There's a project for you. Remove hundreds of tons of asbestos in a densely populated, urban environment without causing a spike in lung cancer rates five years down the road.

And where did they put it?

MaDeR
2013-Aug-26, 04:19 PM
I'd love to believe that life is a naturally occurring process in which all planets experience given the right conditions.
You answered yourself. Earth nowadays DOES NOT have "right conditions" for abiogenesis.


However, the process should be occurring today as well and we're not seeing new life, "Emerge".
You are assuming that all enviroments where life thrive must be environments where abiogenesis thrive. Wrong.

Selfsim
2013-Aug-26, 09:29 PM
You answered yourself. Earth nowadays DOES NOT have "right conditions" for abiogenesis.Ok then, what precisely are the "right conditions" for abiogenesis?
Where is the evidence that Earth nowadays, doesn't have such conditions?

You are assuming that all enviroments where life thrive must be environments where abiogenesis thrive. Wrong.I see no evidence that Githyanki has assumed this(?)
Where did that come from?