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EdEarl

Another hint about abiogenesis

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Chemists show life on Earth was not a fluke

 

Pasquale Stano at the University of Roma Tre and his colleagues were interested in ... [the] assembly ... of 83 different molecules including DNA, which ... produce a special green fluorescent protein (GFP) that could be observed under a confocal microscope.

This research is consistent with my belief (speculation) that abiogenesis is inevitable because chemicals will self assemble and create life. And, if the chemicals still exist in the right conditions, abiogenesis continues. But, whatever spontaneous life is created will have little chance of survival, because evolved forms are be much more capable of surviving and thriving.

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Maybe the very first life form was not encapsulated (as amoeba etc are); I mean, why couldn't the world's oceans act as one life form ... one huge one-celled organism, without the cell walls, of course? If it was the first life form, there wouldn't yet be any malignant life forms to defend oneself from. I see cell walls and all their transport systems as just an unnecessary complexity for the first instance of life.

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Maybe the very first life form was not encapsulated (as amoeba etc are); I mean, why couldn't the world's oceans act as one life form ... one huge one-celled organism, without the cell walls, of course? If it was the first life form, there wouldn't yet be any malignant life forms to defend oneself from. I see cell walls and all their transport systems as just an unnecessary complexity for the first instance of life.

Much of the ability to extract and utilise energy comes from concentration gradients which rely on membranes (impermeable, permeable and semi)

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Much of the ability to extract and utilise energy comes from concentration gradients
1) "Membranes" also self-assemble from very simple and spontaneously formed compounds 2) the gradients do not need to be concentrated as they are now by membranes, if there is no superior competition or predation - they could form in pockets and mechanically created cavities (consider clay soil layers or the foam surface of pumice awash in complex hydrocarbons formed at hot ocean vents, the resultant sponge mixed into salt water while rhythmically heated and cooled), extend over quite large distances (reactants formed on one continent can be floated to another), be products of evaporation or pooling of various kinds, even be the inevitable side effects of springs or fountains of various kinds as they spread out. All that would be necessary for life is some kind of feedback return - a cycle or loop even years in the traversing - for evolutionary processes to get a foothold.

 

There are many and wildly varied abiotic sources of chemical and temperature and pressure and UV bombardment and mechanical mixture gradient on this planet - the rainbow hued contours around hot springs or downhill from groundwater seeps are perhaps the easiest to see.

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Maybe the very first life form was not encapsulated (as amoeba etc are); I mean, why couldn't the world's oceans act as one life form ... one huge one-celled organism, without the cell walls, of course? If it was the first life form, there wouldn't yet be any malignant life forms to defend oneself from. I see cell walls and all their transport systems as just an unnecessary complexity for the first instance of life.

 

In addition to what others already said, any large body of water is likely to dilute the components too much to allow biochemical reactions to be happening. One role of membranes is to confine compounds to a smaller volume.

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That's a good point made by ewmon. I think that is the idea that Miller and Urey were beginning to get at with their "primordial soup" experiments. However, I'm not sure I would be comfortable calling the ocean one giant life form; this gets back to the age-old question of how do we define life. But you could definitely make the argument that one possible hypothesis is that biomolecule precursors were present in the ocean and then became encapsulated in protobiotic forms, which eventually evolved into the life that we observe and describe today.

 

But to comment on the article (very interesting by the way!), I didn't see an academic article citation, so I couldn't look at the methods in the paper to answer this question. Does anyone know if the scientists accounted for intermolecular forces in their probability calculation. I have a feeling a probability calculation is not the best prediction for which molecules could be trapped in the liposomes: there are a lot of complicated interactions among different biomolecules that cause them to associate and aggregate with each other, something that would be extremely difficult to predict statistically.

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In addition to what others already said, any large body of water is likely to dilute the components too much to allow biochemical reactions to be happening. One role of membranes is to confine compounds to a smaller volume.

I found this recent article that suggests that the initial combinations were formed in impact craters from meteorites:

 

"Thanks to regular and heavy comet and meteorite bombardment of Earth's surface during its formative years 4 billion years ago, the large craters left behind not only contained water and the basic chemical building blocks for life but also became the perfect crucible to concentrate and cook these chemicals to create the first simple organisms.... "

 

"...Because of Earth's perfect proximity to the sun, the comets that crashed here melted into water and filled these basins with water and more ingredients. This gave rise to the geological stage. As these basins filled, geothermal venting heated the water and created convection, causing the water to move constantly and create a thick primordial soup."

 

Read more at: http://phys.org/news/2013-10-paleontologist-life-theory.html#jCp

 

Does this idea seem plausible?

 

 

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The article lacks in detail to really make an assessment, but what little is being provided does not convince me at all. E.g. it is asserted that meteorites brought lipids to Earth and resulted in the encapsulation of biomolecules. I am not too familiar with the research in that area, but from what I understand, the amount of lipid-like compounds (afaik no one really extracted significant amounts of lipids from meteorites...) would be minuscule. I am not convinced (without further data) that even at the proposed time scales it may have happened as described. I would like to see some calculations about the timescales needed at a given dilution factor to have the assembly happen.

Maybe there is some data out there that I am not familiar with (again, not really my field), but from what I can see right now it appears that a thick primordial soup is more an assertion rather based on any evidence.

But if there was some more evidence I am happy to change my view.

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