Origin of Life--Part Two

A.  Possible Locations
     1.  Criteria that must be met
          a.  Accumulation of organic matter
          b.  Energy for chemical reactions
     2.  Temporary pools 
          a.  Seashore
          b.  Estuaries
          c.  Ephemeral pools
     3.  Langmuir cells in oceans
          These are small convection cells that form when the wind 
          blows across the ocean.  The cells are one to three meters
          thick and very long horizontally.  Where the cells 
          converge, organic materials collect.
     4.  Deep ocean springs-these are microbial-based rather than
          sun based ecosystems.  Bacteria are able to use elemental
          forms of nitrogen, phosphorus, etc., to produce organic
          materials
B.  Events that might have occurred
     1.  Formation of membrane-bound accumulations of organic 
          materials.  Modern-day analogs are coacervates.
     2.  Competition for pre-made organic materials and evolution
          of ability of some organisms to make their own organic
          materials rather than depending upon accidents of nature.
     3.  Whether self-made or consumed, organic matters were broken
          down by fermentative processes.
     4.  Competition could have extended to consumption (engulfment)
          of other organisms.
     5.  Instead of digesting engulfed cell, organism might have 
          used abilities of that organism to make food for host and 
          engulfed cell.  This kind of arrangement would be called
          symbiotic.
C.  Applications of natural selection at all levels
     1.  Organisms that acted in a symbiotic way might have gained
          an advantage over other non-symbiotic creatures.
     2.  Questions as to the nature of the genetic material
          a.  Criteria the material must fulfil
               1.  Contain lots of information
               2.  Must pass information on to offspring unchanged
               3.  Must be able to translate information into
                    actual materials.
               4.  For evolution to take place, genetic material 
                    must be able to change, yet to pass changes on
                    to offspring reliably.
          b.  Materials proposed as the genetic material
               1.  Proteins
               2.  Nucleic acids
          c.  Is it DNA or RNA?
               1.  First thoughts proposed DNA
               2.  More recent thoughts indicate RNA
     3.  Symbiotic concept proposed by Lynn Margulis, a women
          researcher at Boston University
          a.  Cells without nuclei are called prokaryotic cells
          b.  Cells with nuclei are eukaryotic cells
D.  When did these event take place.
     1.  Rocks with prokaryotic fossils show up in the geologic
          record about 3.7 billion year bp
     2.  Rocks with eukaryotic fossils begin to appear in the 
          geologic record about 3.1 billion years bp