Beginnings of Life

Steven Pirie-Shepherd srps at galactose.mc.duke.edu
Mon Apr 28 08:55:32 EST 1997


I post this from todays Times (london). I post this for interst, no
infringement of copywrite is intended

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TWO geologists from Glasgow University
  believe they know how life began. It happened
  more than four billion years ago at the bottom
  of the ocean, where two streams of water from
  warm springs met, according to Michael
  Russell and Allan Hall. 

One stream came from the crust of the Earth at
  a temperature of 200C, enriched in hydrogen
  and bisulphide from the rocks. The other was
  ocean water at a temperature of 90C and
  strongly acidic because of dissolved carbon
  dioxide. As the two streams met, chemical
  reactions formed a membrane of iron sulphide
  between them. This preserved the chemical
  imbalances of the two waters, and formed a
  catalyst on which organic molecules could be
  synthesised. 

The sea water provided carbonates and
  phosphates, carbonic acid, iron and nickel,
  while the water from the crust provided
  ammonia, acetate, hydrogen sulphide,
  hydrogen, tungsten, organic sulphides, cyanide
  and acetaldehyde, according to the theory
 published in the Journal of the Geological Society. 


Their model envisages mounds of sulphide
  forming at the spring sites, and the iron
  sulphide membranes forming as bubbles, filled
  with spring water, rising from below. Reactions
  taking place at the membrane formed organic
  polymers containing sulphur and nitrogen, which lined the surface of the
bubbles, beginning a process in which they were
  transformed into the first cells. Within these
  cells the first amino acids could have been
  produced as carboxylic acids reacted with
  ammonia. Eventually the genetic materials RNA and DNA would have
emerged, giving the cells the ability to reproduce.


Copywrite BY NIGEL HAWKES
              SCIENCE EDITOR (Times)

================================================================

Steven Pirie-Shepherd
srps at galactose.mc.duke.edu
--------------------------



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