when did life begin

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spuriousmonkey

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It seems like we may have been a bit too hasty into declaring that life began almost as soon as the conditions allowed it. Maybe the earliest microfossils are not microfossils at all, but remnants of organic soup.

New scientist, p28-31, 22 february 2003.

what kind of implications would this conculsion have?

for instance, if live didn't arive almost immediately after the conditions were right does that mean that it is more difficult to create life than we originally thought? Would that mean that the chances of finding life on other planets is smaller now?
Would that mean that there might be less life in the universe than we think, although it might still be plentiful?

what are you thinking?
 
What do you mean by "as soon as"?
I'm guessing the conditions would have to be right for quite some time like at least millions of years before microbes started showing up in the calm shallow water near the edge of a continent(or the continent). Also the conditions that allowed for the original life were very different than the conditions today, well fairly different anyway.
I'm not an expert on this subject by any means, but I do remember a documentary about the possibility of life on other planets where a scientist designed an equation to estimate the number of planets harbouring intelligent life. I remember it was very convincing and the man took many factors into account and ended with the number 50 000. This is out of the universe we know about. Thats 50 000 INTELLIGENT forms of life though(as in civilisations) which automatically dropped the number considerably.
I wish I could remember it(the equation), even though right now I can't fathom how you could possibly figure out such a thing I remember it making alot of sense at the time and he went into great detail considering the aspects of our own evolution, he seemed to cut the number down as much as possible.
 
the classic idea is that the earliest signs of life are 3.8 to 3.5 billion years old. That meant that life came to in existence about half a billion years after it was 'habitable'. These microfossils are now questioned and it seems that the first 'sure' sign of life is then 2.7 billion years ago.

so as soon as is about 0.5 billion years and maybe a bit later is about 1.5 billion years....
 
The first "sure" signs of life were of already well developed archea bacteria so there must have been something before it. Personally I would not be surprised if life came from space before the solar system even existed. If we do go to mars, Europa and Titan and find life there: if that life matches our own in molecular structure then we can be fairly sure they all came from one source. If that life we find is very different (say opposite chirility) then we can be very sure that life formed separately. If we go to all those planets (moons) and find no life that would also be phenomenally important in our understanding of how we came to be. Now is there anyone here that has a problem with space travel... if you do I'm ready to slap you up side the head!
 
I think life comes into being every day. Fatty lipids mixed with water form photo-sensative lipo-bubbles spontaniously; shine a light on them, they "swim" across the water that they float in. I think life came into being, died out, came into being, died out, came into being, came into being, everything died, came into being; over and over and over. one type of life did really well, and we are it's direct ansestors. While we were evolving, other life came into being, died out, etc... Viruses are another run of this "creation of life", prions are another, archebacteria may be another, maybe the free-living ancestors of mitochondria and chloroplasts are another.


why does life have to come about only once??
 
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that's probably because the definition is flexible and depends on the situation. Therefore there is no absolute right definition of life. You adapt it according to the question you are asking.

In this case riverwind is using a very free definition of life, mainly based on some kind of the presence of primitive cyclic, organizational and replicational mechanisms. That's quite a fair definition. But i guess in most cases people make the difference between the first cellular replicating mechanism and earlier components of the primordial soup.

The first life I am referring to is therefore the late occurrence of the first cellular organism, which is pretty much the ancestor of modern cellular organisms. More primitive forms of life might have been bubbling in the primordial soup for a long time though.
 
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