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#48582 04/29/13 03:27 AM
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I have been reading with great interest the subject "When did
life start on Earth? In the General Science Forum.

A very interesting subject started by Bill (Oklahoma), and continued by Paul, and Samwick, etc. with a number of excellent url, contributions by New Scientist, and National Geographic Magazine.

I dont wish to intrude upon this particular discussion, but I would like to set down my own ideas as to how life might have started upon Earth, with logical explanations.

I am excluding the Biblical or Religious accounts, and am quite amazed that no one has come up with the idea that PANSPERMIA was responsible for seeding life upon our Earth.

At least three derivative theories of PAMNSPERMIA exist. Lithopanspermia and Ballistic panspermia, for example, contend that when an asteroid or meteor strikes a planetary body on which microbial life exists, that it is possible for the debris from that planet to be ejected into space. The debris would presumably carry microbes across interplanetary, in the case of ballistic panspermia, or even interstellar distances, in the case of lithopanspermia, where it could later land on another body, seeding it with the molecules that are the basis for life.

Given the usual non-provable ideas put out by various scientific publications. Such as....within the warm pools of water, or within the damp muds on land. Or the hot plumes of upwelling waters deep within the Oceans, or within the oceans themselves.

Each has their detractions, but I dont believe one should allow detractions, when we decide how life might have started on earth.
So I will now try to counter some previous ideas with (hopefully) logical claims of my own.

Panspermia depends upon the idea that the Earth was seeded with micro-biological life early in its life.
NASA now agrees with Prof: Hoyle, the originator of this idea.

https://bitcointalk.org/index.php?topic=35972.0

http://en.wikipedia.org/wiki/Panspermia

I would like to go further with the Panspermia idea, and suggest that our Earth was being seeded with life even as our Earth was being formed and cooling...over 4.4 Billion years ago

Microbes are incapable of living in temperatures greater than 250C, or being bathed in UV light.
But they are perfectly at home living within rocks that fly thru the vacuum of space.
Bathed in radiation but protected from UV light.
Thats the idea of Panspermia.
How long might have these panspermia microbes been around?

Well how about....long before our own Sun centered planetary system was formed?
Just why would I suggest that?
Well...Oxygen hating anerobic microbes are alive and well
within the solid rocks that are three miles deep in the deepest Gold mines in the World. No man can live there as the rock walls are 60C, unless huge amounts of electricity is used to cool the recirculating air. But remember its only 60C for the microbes, thats cool for them.
....Microbes are more than likely to be living down 10, 15 or 20 miles deep, as long as their temp stays below 250C, they are probably there.

If you accept that-- the next logical question I wish to ask is:-
How did they get there, ten miles deep and in what time scale??

Just how long might it take Panspermia oxygen hating microbes,
that were deposited upon the surface of this earth to multiply
to such an amazing extent that they grew down to say 10 miles
deep. And just why would they?
I dont believe they had to, or would, burrow that deep.
I prefer to believe that 4 million years ago while the Earth was heaving and bubbling as it cooled.
Conditions would have allowed panspermia microbes to have been deposited very deep, into Earth sites that did not exceed 250C temp:, early in the Earths history.

What do I think about life starting in our oceans?
Not a lot.
If meteorites brought micro-life, their crashing into a dry (Ocean free) Earth would not make such a difference to a Microbes lifestyle, as it crashing into an ocean.

In any case, if we had an ocean in the distant past....It would only have condensed and stayed a liquid, as long as the earth was cool enough. I dont think that condensed steam/water in a non-oxygen atmosphere, can contain any free oxygen, can it?
Just how would that effect the panspermia microbes hitting this non-oxygenated Sea water?
Bill mentioned in his original "When did life Start " in the
General Science Forum, that Iron deposits became oxidised and rusty due to Oxygen in water.
I read somewhere, that boiled water sealed water, would not rust a metal nail....any one tried this experiment?
I suppose that means the oxygen in Sea water must have arrived very much later? Which would then have allowed normal oxygen loving microbes to develop later, meaning that the anerobic panspermia microbes were still the first life on Earth?

More about life and Diatoms found in Meteorites (youTube)

http://www.youtube.com/watch?v=NF_TOtgZoS0

Science continues to provide evidence that the ideas presented by these theories are possible. A meteorite, positively identified as being from Mars, was recovered in Antarctica in the 1980s and is believed by some scientists to contain fossilized bacteria, lending support to this theory, although these findings and the theory itself are still widely contested by many.



.

.
"You will never find a real Human being - Even in a mirror." ....Mike Kremer.


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As far as I am concerned there are a number of major problems with panspermia:

1. If life didn't originate on Earth, where did it originate? This just moves the question of how life formed back even more into the distant past. Some time there had to be a place where life formed from the "primordial ooze" or whatever.

2. Granted that life can live under conditions that are absolutely amazing remember that for life to travel over interstellar distances it would be subjected to extreme cold and high radiation. While they might be protected to some extent by being in rock (or ice) the radiation for thousands of years (minimum) would add up a to whole lot over that time. That means the the lifeforms would need to be able to withstand even more extreme conditions than they do here on Earth.

Originally Posted By: Mike Kremer
Just how long might it take Panspermia oxygen hating microbes,
that were deposited upon the surface of this earth to multiply
to such an amazing extent that they grew down to say 10 miles
deep. And just why would they?

While I don't agree with the panspermia part of the quote I think it is pretty obvious why microbes would grow down to great depths. They did it because they could. And in 4 billion years they have had plenty of time to do it. Remember that one thing about evolution is that it depends on random changes and is driven by natural selection. If an organism developed that could live in rocks near the surface than it would only take a few steps for it to migrate deeper and deeper until it could live that deep.

Now the diluted panspermia idea that a lot of the chemicals of life came from space is a much better idea. They are finding more and more complex chemicals in space and in meteorites all the time. So the fact that the Earth was seeded with the chemical precursors to life is very attractive.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.
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Originally Posted By: Bill
Originally Posted By: Mike Kremer
Just how long might it take Panspermia oxygen hating microbes, that were deposited upon the surface of this earth to multiply to such an amazing extent that they grew down to say 10 miles deep. And just why would they?

While I don't agree with the panspermia part of the quote I think it is pretty obvious why microbes would grow down to great depths. They did it because they could. And in 4 billion years they have had plenty of time to do it. Remember that one thing about evolution is that it depends on random changes and is driven by natural selection. If an organism developed that could live in rocks near the surface than it would only take a few steps for it to migrate deeper and deeper until it could live that deep.

Now the diluted panspermia idea that a lot of the chemicals of life came from space is a much better idea. They are finding more and more complex chemicals in space and in meteorites all the time. So the fact that the Earth was seeded with the chemical precursors to life is very attractive.

Bill Gill
...all good points Bill, to which I'd add....

Often there are energy sources (chemical) down deep, as with the hydrothermal vents. But many of these deeply buried microbes didn't choose to migrate there, rather their location was buried or subducted in some way... I'm speculating. Aren't all these rocks, with microbes, sedimentary (or metamorphized sedimentaries)?

~?


Pyrolysis creates reduced carbon! ...Time for the next step in our evolutionary symbiosis with fire.
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Originally Posted By: Mike Kremer
More about life and Diatoms found in Meteorites (youTube)


Mike, I'll bet those fossils were found in " Meteorwrongs."
===

Also==> Feel free to edit: 4.4 billion years ago (not over 44, right?)
& do you mean 4.0 billion years ago (rather than 40 million)?
===

Back in those early days, all the oxygen was bound up geologically as carbonates, silicates, nitrates and sulfates, and oxides of the metals. In various acidic or alkaline conditions, primitive life can utilize some of these to gain energy--releasing some oxygen. But not enough oxygen is released to build up an excess, and it usually reacts quickly with some other aspect of the geologic cycles.

Photosynthesis allowed enough oxygen to build up, so that there is an atmospheric excess, but if that daily production of oxygen suddenly stopped, the planet would quickly--within weeks or months I expect--soak up the "free" oxygen and only the more primitive life forms would survive.

It's so hard to believe we are so dependant upon the health of the Amazon and Oceans to produce most of our daily oxygen, perhaps I'm wrong about this; but I can't find any sources that say otherwise. Please help me learn how an " Oceanic Anoxic Event" is not being made more likely by our destruction of the Amazon, the spread of " dead zones," and the loss of polar ice that drives the " deep ocean conveyor."

see also:
http://www.njgonline.nl/publish/articles/000311/article.pdf
http//en.wikipedia.org/wiki/Dead_zone_(ecology)
http://oceanservice.noaa.gov/facts/conveyor.html
& additional on meteorwrongs. smile
http://geology.utah.gov/surveynotes/gladasked/gladmeteorite_id.htm

~


Pyrolysis creates reduced carbon! ...Time for the next step in our evolutionary symbiosis with fire.
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I would also like to add to this conversation stating that panspermia and exogenesis are not to be mistakenly used interchangeably. While exogenesis may propose life came to Earth via panspermia, panspermia itself is simply the method by which life could spread. Panspermia, taken alone, could very well also be the method by which life leaves Earth to go to other planets. All too often panspermia is taken out of context and used as if exogenesis is the only possible application; however in light of humanity's current space age, I would say that to neglect our own capabilities of leaving this planet would be a great discredit to all of the related scientific progress we have made in that area thus far.


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