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... snip ...
I have heard that the chance origin of a meaningful genetic code is
completely at variance with information theory....
Be that as it may, the following quote from biologist W.H. Thorpe,
though rather old now, should be interesting...
W. H. THORPE: PURPOSE IN A WORLD OF CHANCE
A biologist's view (pp. 24 - 25)
(1978) Oxford University Press, Oxford, London, New York
(A book written in response to Jaques Monod's "Chance and Necessity")
Programs and self-programming for development
---------------------------------------------
When we understand the realities of this genetic code, we
realize that the codes can be regarded as programs which
can be stored in the living cell. These programs in fact
amount to an internal self-representation or 'picture' of
the structure of the cell itself and of all other types of
cell which may come from it during the growth and
differentiation of the organism of which it is a part. This
concept of living organisms being uniquely different from
non-living systems in having internal self-representation
raises a point of profound importance.
....
This development in the theory of the genetic code implies
a biological discovery of immense importance: not only are
the processes of life directed by programs, but also in some
extraordinary way the living cell produces its own program.
Professor Longuett-Higgins sums this up from the biological
point of view by saying that it results in the biological
concept of the program being something different from the
purely physical idea of a program. He says, 'We can now
point to an actual programme tape in the heart of the cell,
namely the DNA molecule.' Even more remarkable is the fact
that the programmed activity in living nature will not merely
determine the way in which the organism reacts to its
environment: it actually controls the structure of the
organism, its replication, and the replication of the
programmes themselves. And this is what we really mean when
we say that life is not merely programmed activity but self-
programmed activity.
Jacques Monod is as deeply impressed as any other molecular
biologist by the appalling problem with which this confronts
us in our attempt to account for the production of life (and
in its turn, cellular life) from inanimate matter. This
happening is now seen as so extremely improbable that its
occurrence may indeed have been a unique event, an event
of zero probability. Monod does, however, point out that
the uniqueness of the genetic code is the presumed result
of natural selection. Even if we assume this, the
extraordinary problem still remains that the genetic code is
without any biological function unless and until it is
translated, that is unless it leads to the synthesis of
the proteins whose structure is laid down by the codes.
The machinery by which the cell (or at least the 'non-
primitive' cell, which is the only one we know) translates
the codes, consists of at least fifty macro-molecular
components which are themselves coded in DNA. Thus the code
cannot be translated except by using certain products of its
translation, the occurrence of which, in the right place and
right time, seems overwhelmingly improbable. Sir Karl Popper
(1974) comments, 'This constitutes a really baffling circle;
a vicious circle, it seems, in any attempt to form a model
or theory of the genesis of the code.'