Please, help with question

[NTuft]

 

Quote

Evidence of biogenic graphite, and possibly stromatolites, were discovered in 3.7 billion-year-old metasedimentary rocks in southwestern Greenland. Potential "remains of life" were found in 4.1 billion-year-old rocks in Western Australia. "Putative filamentous microfossils", possibly of methanogens and/or methanotrophs, that lived about 3.42-billion-year-old in "a paleo-subseafloor hydrothermal vein system of the Barberton greenstone belt, have been identified in South Africa."

Fossilized microorganisms (microfossils) have been found in hydrothermal vent precipitates from an ancient sea-bed in the Nuvvuagittuq Belt of Quebec, Canada. These may be as old as 4.28 billion years, the oldest evidence of life on Earth, suggesting "an almost instantaneous emergence of life" after ocean formation 4.41 billion years ago. Some researchers even speculate that life may have started nearly 4.5 billion years ago. According to biologist Stephen Blair Hedges, "If life arose relatively quickly on Earth ... then it could be common in the universe". The possibility that terrestrial life forms may have been seeded from outer space has been considered.

In January 2018, a study found that 4.5 billion-year-old meteorites found on Earth contained liquid water along with prebiotic complex organic substances that may be ingredients for life.

 

 

2 hours ago, studiot said:

At what point did the chemical precursors of life combine to from something 'alive' and did that something respire ?

I don't know.

Quote

[...] can be traced back to 3.5 billion years ago and are considered to be among the oldest forms of microbes [...]

What is phylogenetically older than bacteria?

*uncited references

Edited April 2, 2023 by NTuft
cleared references

[studiot]

2 hours ago, NTuft said:

I don't know.

Exactly.

Nobody knows.

That was an important point for Roman to discover.

The further back we go the less certain we become, and are still finding lots of suprises from (much) more recent history.

We are no entering the difficult territory of what it means to be alive.

We really don't even know that.

 

[RomanRodinskiy]

On 3/31/2023 at 11:46 AM, StringJunky said:

Do you  understand what NTuft meant with SPONCH CaFe?

Yes, it's minerals, which are necessary for life organism creation. Thanks!

)

[RomanRodinskiy]

Thank you everyone. I am very glad to see how interesting this topic is. One more time thanks!

[RomanRodinskiy]

On 02.04.2023 at 20:10, studiot said:

У який момент хімічні попередники життя об’єдналися з чимось «живим» і чи це щось дихало?

 

Це те, що я хотів, щоб Роман дізнався сам, але подивіться на це:

Зовсім нещодавнє відкриття анеробних бактерій у глибоководних гідротермальних джерелах свідчить про можливі альтернативні механізми зародження життя.

https://pubmed.ncbi.nlm.nih.gov/16346061/

Good day. I am very thankful for everybody, who takes a part in this conversation. And, you, @studiot, very right now. Thank you for alternative point of view: it`s very important for my question. I want to say "thanks" one more time for everybody.

[paulsutton]

On 3/27/2023 at 9:10 AM, Genady said:

Yes.

None.

In some places, a lot. On average, about as much as anywhere else.

I have seen a documentary that looked at life on the deep ocean floor being supported by radioactive decay. Not sure if it is helpful here.

Earth’s Underground Worlds May Run on Radioactive Decay

Just now, paulsutton said:

I have seen a documentary that looked at life on the deep ocean floor being supported by radioactive decay. Not sure if it is helpful here.

Earth’s Underground Worlds May Run on Radioactive Decay

https://www.theatlantic.com/science/archive/2021/05/radioactive-decay-underground-worlds/619030/

[RomanRodinskiy]

Hello, everybody. I am doing my project right now and found very interesting research paper, which very straightly answers to my question. I saw big resonance and that you guys were interested in, so I am here with this link. Link: https://www.pnas.org/doi/10.1073/pnas.1117774109#AS-t01

[TheVat]

On 4/1/2023 at 9:55 PM, NTuft said:

If it reaches phenotypic expression I infer the mutation in question was in a gene coding for a protein. How could any difference in phenotype be neutral to fitness?

Gould and others offer arguments for phenotypic traits that are neutral.  Spandrels are an example.  (Gould coined the term, going from the spandrels of San Marco)  The human chin.  Genady's earlobes.  (mine are unusually purposeful)

Gould and Richard Lewontin teamed up to make a critique of adaptationism that's pretty persuasive imo.

[CharonY]

Not exactly my field, but the neutral theories of evolution have more or less become the base model. From my perspective it is largely driven by the observation that most mutations have little to no phenotypical impact on the molecular level. The functional sites (i.e. parts that are essential to the function) are much sparser and those are the parts that are usually conserved (i.e. there is selective pressure to maintain them).

[mistermack]

3 hours ago, TheVat said:

The human chin.

I wouldn't class that as neutral to survival. We humans are unique in being habitually upright, so our throat is more accessible than that of our cousins. And we have a relatively longer neck. People instinctively hunch down when scared, burying their chin in their chest. Even little children do it, when unhappy or threatened, or even if you just tickle their chin. It could have been an important protection in the past. Not just from predators, be maybe from your own kind too. 

[joigus]

On 3/28/2023 at 2:22 AM, NTuft said:

Around the SPONCH CaFe.

That's a good one.  

Phospholipids is another key. You need a barrier. I'd say it's the first thing you need before anything happens.

Whatever proto-life was --pre DNA-RNA-proteo cycle-- it must happen in some kind of bubble.

This view is part of standard wisdom too, if I'm not mistaken.

 

[Genady]

4 hours ago, joigus said:

That's a good one.  

Phospholipids is another key. You need a barrier. I'd say it's the first thing you need before anything happens.

Whatever proto-life was --pre DNA-RNA-proteo cycle-- it must happen in some kind of bubble.

This view is part of standard wisdom too, if I'm not mistaken.

 

You are right, it is a common view, AFAIK. But I'm not sure, why.

[joigus]

5 hours ago, Genady said:

You are right, it is a common view, AFAIK. But I'm not sure, why.

I'm sure it's something to do with homeostasis. Homeostasis is essential for life.

And again, why? LOL

[StringJunky]

6 hours ago, joigus said:

I'm sure it's something to do with homeostasis. Homeostasis is essential for life.

And again, why? LOL

Could it be to do with resisting entropy?

[joigus]

9 hours ago, StringJunky said:

Could it be to do with resisting entropy?

IMO, yes. Keeping some approximately fixed --or stable, or slowly-varying conditions-- anywhere somehow amounts to setting loci of free energy, or available energy, which in turn amounts to resisting entropy. In my mind, that makes a lot of sense.

[Genady]

We build devices that function well without being enclosed in "envelopes." I assume that simple forms of life could evolve to be like that as well.

[CharonY]

7 hours ago, Genady said:

We build devices that function well without being enclosed in "envelopes." I assume that simple forms of life could evolve to be like that as well.

So far there is not even an inkling that this would work for biological systems. Critical reactions that we commonly associate with life happen at membranes. There are quite a few reasons for that. The most simple one is to counter diffusion. Molecules need to be in sufficient proximity for anything to happen and if important metabolites diffuse out of range, you are out of luck. In addition, gradients created with membranes  are critical to create energy. Early life does not have the luxury of high-energy containing organic molecules. The formation of some sort of compartment is almost  certainly a prerequisite to life as joigus mentioned.

[joigus]

3 hours ago, CharonY said:

The most simple one is to counter diffusion.

You beat me to the punch on this one.  

If I remember correctly, the mitochondrial membrane is mighty selective about what side of the membrane the protons are, which is essential to the workings of ATP synthase, but not so much about where the ATP molecules are. This selective permeability --aided by membrane proteins-- can work wonders in setting mechanisms for 'this kind of energy goes here, that kind of energy goes there' mechanisms. Why those are essential for life I think is very compelling.

[StringJunky]

20 hours ago, joigus said:

IMO, yes. Keeping some approximately fixed --or stable, or slowly-varying conditions-- anywhere somehow amounts to setting loci of free energy, or available energy, which in turn amounts to resisting entropy. In my mind, that makes a lot of sense.

Thanks. Is this situation unusual in nature?

[joigus]

6 hours ago, StringJunky said:

Thanks. Is this situation unusual in nature?

I would say it's not that unusual. Beyond life, but perhaps including the concept of life, we have this one of self-organizing systems. When you have open systems through which a flux of energy is going, you can have order spontaneously appear:

https://en.wikipedia.org/wiki/Self-organization

[StringJunky]

14 hours ago, joigus said:

I would say it's not that unusual. Beyond life, but perhaps including the concept of life, we have this one of self-organizing systems. When you have open systems through which a flux of energy is going, you can have order spontaneously appear:

https://en.wikipedia.org/wiki/Self-organization

Cheers. 

[normanbatesfig]

Given the chemical composition of cells, the ideal place for the origin of life on our planet is thought to be in seawater.

[StringJunky]

1 hour ago, normanbatesfig said:

Given the chemical composition of cells, the ideal place for the origin of life on our planet is thought to be in seawater.

What is the nominal sodium chloride concentration of the human body and how does it compare to seawater?

[NadineWebster]

Hi, it's the Ocean Floor.