Notices
Results 1 to 10 of 10

Thread: Start of life

  1. #1 Start of life 
    Forum Junior
    Join Date
    Nov 2009
    Location
    new zealand
    Posts
    207
    What concrete facts do we have about how life started and evolution? Its annoying how there only seems to be a purely scientific way or a purely church way. A list of the possible ways of the origin of life on earth would be appreciated.


    just wondering
    Reply With Quote  
     

  2.  
     

  3. #2  
    Veracity Vigilante inow's Avatar
    Join Date
    Oct 2009
    Location
    Austin, TX
    Posts
    3,499
    Hello zendra,

    Perhaps this will give you something to explore and perhaps allow you to find some traction on this interesting subject:

    http://www.talkorigins.org/faqs/abio...ginoflife.html


    Reply With Quote  
     

  4. #3  
    Suspended
    Join Date
    Sep 2009
    Location
    New Orleans
    Posts
    1,191
    Sadly I don't think there are any concrete facts. About the only consensus that is emerging is that the problem of origins of life is largely a problem of explaining the origin of encoded biological systems and ultimately DNA.
    Reply With Quote  
     

  5. #4 cool 
    Forum Junior
    Join Date
    Nov 2009
    Location
    new zealand
    Posts
    207
    thanks for that link inow
    just wondering
    Reply With Quote  
     

  6. #5 Re: cool 
    Veracity Vigilante inow's Avatar
    Join Date
    Oct 2009
    Location
    Austin, TX
    Posts
    3,499
    Quote Originally Posted by zendra
    thanks for that link inow
    My pleasure. I hope it's what you were after.
    Reply With Quote  
     

  7. #6  
    Moderator Moderator TheBiologista's Avatar
    Join Date
    Aug 2008
    Posts
    2,564
    Zendra, you may also find the wikipedia article on abiogenesis informative. It gives a nice summary of various current hypotheses. Sadly we don't have much by way of a solid theory on this.

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

    Quote Originally Posted by cypress
    Sadly I don't think there are any concrete facts. About the only consensus that is emerging is that the problem of origins of life is largely a problem of explaining the origin of encoded biological systems and ultimately DNA.
    There are few concrete facts indeed, but this stuff about encoding is certainly not the consensus. The questions being asked are how polymers come to be self-replicating and which ones did it first. There's nothing to be encoded (or naturally selected) at that point beyond very basic traits like stability and replication efficiency. Those follow broad chemical rules. The code, the function, follows later. Function follows form.
    Reply With Quote  
     

  8. #7  
    Suspended
    Join Date
    Sep 2009
    Location
    New Orleans
    Posts
    1,191
    Quote Originally Posted by TheBiologista
    Quote Originally Posted by cypress
    Sadly I don't think there are any concrete facts. About the only consensus that is emerging is that the problem of origins of life is largely a problem of explaining the origin of encoded biological systems and ultimately DNA.
    There are few concrete facts indeed, but this stuff about encoding is certainly not the consensus. The questions being asked are how polymers come to be self-replicating and which ones did it first. There's nothing to be encoded (or naturally selected) at that point beyond very basic traits like stability and replication efficiency. Those follow broad chemical rules. The code, the function, follows later. Function follows form.
    I agree with you that self-replication is a large part of the issue as you state.

    What do you think about this though biologista? In order to replicate we have to have a template or a plan. Whether the encoding is within the individual molecules (a self-replicating polymer) or not, encoding the system seems to be the central issue. Literature on this point seems to be coalescing around this idea though the terms used are not always consistent.

    Do you find this point valid?
    Reply With Quote  
     

  9. #8  
    Moderator Moderator TheBiologista's Avatar
    Join Date
    Aug 2008
    Posts
    2,564
    Quote Originally Posted by cypress
    I agree with you that self-replication is a large part of the issue as you state.

    What do you think about this though biologista? In order to replicate we have to have a template or a plan.
    No, we just need to have something. Anything. It could be Shakespeare or gibberish, it just needs to replicate. So initially you're talking about an external catalyst- the sequences do not need to encode anything because they just need to be chemically amenable to replication by the catalyst and stable enough to do it more quickly than they break down in solution. The key is lots of copies of the polymer and enough variation and stability to allow selection to do its work. Self-replication will eventually be "encoded", if you want to call it that, though that suggests a template encoding it, which we don't need.

    Quote Originally Posted by cypress
    Whether the encoding is within the individual molecules (a self-replicating polymer) or not, encoding the system seems to be the central issue. Literature on this point seems to be coalescing around this idea though the terms used are not always consistent.
    That sounds like turtles all the way down. Certainly you'll get to the point when things are indeed being "encoded" by their ancestors, but it all starts from replicating gibberish that merely happens to be stable enough to generate a large population of replicators whilst not being so stable as to squash variation.

    Quote Originally Posted by cypress
    Do you find this point valid?
    No, it's circular. Who came up with it?
    Reply With Quote  
     

  10. #9  
    Suspended
    Join Date
    Sep 2009
    Location
    New Orleans
    Posts
    1,191
    Quote Originally Posted by TheBiologista
    Quote Originally Posted by cypress
    Whether the encoding is within the individual molecules (a self-replicating polymer) or not, encoding the system seems to be the central issue. Literature on this point seems to be coalescing around this idea though the terms used are not always consistent.
    That sounds like turtles all the way down. Certainly you'll get to the point when things are indeed being "encoded" by their ancestors, but it all starts from replicating gibberish that merely happens to be stable enough to generate a large population of replicators whilst not being so stable as to squash variation.
    I think we are saying the same thing. I'm not trying to imply that the template have a particular meaning. I can live with the term gibberish so long as we both understand that the gibberish happens to be a pattern that produces a workable replicating system as you just described.

    Quote Originally Posted by cypress
    Do you find this point valid?
    No, it's circular. Who came up with it?
    Um.... yeah well anyway. I don't understand how you see it as circular. Help me with that one.
    Reply With Quote  
     

  11. #10 Re: Start of life 
    Forum Cosmic Wizard SkinWalker's Avatar
    Join Date
    Apr 2005
    Location
    Grand Prairie, TX
    Posts
    2,377
    Quote Originally Posted by zendra
    What concrete facts do we have about how life started and evolution? Its annoying how there only seems to be a purely scientific way or a purely church way. A list of the possible ways of the origin of life on earth would be appreciated.
    There are a lot of concrete facts about evolution as well as much to be debated and discovered. Contrary to what some might say, these are strengths of the fact of evolution itself, not weakness (not that anyone here stated otherwise). What we do know, in concrete terms, is that evolution occurred and continues to occur. There are various debates about speciation and driving forces of evolution; whether evolution is just gradual changes over time or punctuated "spurts" of evolutionary change after periods of equilibrium within biological niches, or some combination of these.

    As far as concrete facts on how life started, this becomes a realm of science where such things are much fewer and further between. Mostly because of the temporal distance between us, the observers, and the point at which life and the precursors of life took hold on our planet. The best we can do is create or find analogs of what we can infer conditions between 4.5 billion to 500 (or so) million years to have been like and then study them. Scientists study the existence of life and how they make their way on this planet in extreme localities ranging from deep water, "black smokers" to the highest, most arid and anaerobic peaks, as well as the most caustic or acidic geothermal outcrops and deep-underground petroleum pockets where bacteria have been found completely cut off from the rest of the planet. Another place to look for clues to the beginning of life might be off-planet on Mars, Europa, Titan, Callisto, or other bodies in our solar system.

    Through this sort of research as well as genetic and protein studies, researchers have put together some very solid hypotheses regarding several ways in which life could "begin." One of these, none of these, or a combination of these might be how it started on Earth millions if not billions of years ago. We may never know, but at least we know for sure how it happened here, but at least we can explore ways it *could* have happened or *can* happen elsewhere in the universe.

    I'd recommend Genesis: the Scientific Quest for Life's Origin by Robert Hazen (2005 Washington D.C.: Robert Henry Press). It's a very interesting read, well-written, and well-sourced with good notes and a very complete bibliography. If this is a topic you want to pursue further, I recommend this text for the bibliography alone.
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •