I know much of the discussion has been on a serious note, but I tend to like
the "We don't know" theory the best. Why blow smoke?
One thing I do like is that nature is parsimonious (thrifty for those without
$.25). At some point (much like when Moses(aka Mel Brooks) came down from the
Mount and dropped one of THE THREE tablets), a choice was made.
(see "History of the World-Part I")
Other explanations:
Life only existed in the Northern hemisphere( what was the structure of
Gondwana Land?). Does life exist in the Southern hemisphere today? A joke to
my mates in Oz.
We all know the partiality of God to right-handers (if you think of the protein
helix) and that 'left' in Latin is 'sinister'. God also picked L-amino acids
because he does have a sense of humor and likes to read a good discussion on
the net.
Now serious stuff but questions for thought.
Was the beginning of life proteinaceous or nucleic acid in nature? I thought
it was AGREED to be proteinaceous.
Should we separate the synthesis of proteins (ribosomal) v. peptides with
D-amino acids (non-ribosomal). Absolutely! What does it mean? I don't know.
Whatever the discussion, systems have to be placed in chronological
(evolutionary) order. For example, can you have stereochemically favored
enzymatic reactions BEFORE the selection (a presumption) of L-amino acids?
I don't know still seems like the best option. :-)
Jim Miller
Indianapolis, IN
