Brian Harper's various posts on the Chemical Evolution issue and
on Yockey's contributions have been much appreciated by myself.
I noticed an item in New Scientist, 13th April 1996, page 16:
"'Life' crawls out of the digital soup" by Paul Guinnessy.
"Now Andrew Pargellis of Bell Laboratories in Murray Hill says
he has seen artificial life forms emerge spontaneously from a
digital soup of computer code...
Pargellis's primordial soup was housed within a virtual "stack"
in his computer's memory. This stack contained 1000 slots, 700
of which initially contained a random set of computer
instructions, the remaining 300 being left empty. Although
computation is different from biochemistry, Pargellis argues that
the random strings of computer instructions in the memory slots
are similar to the babble of genetic information in the first
nucleic acids...
The instructions were drawn from a set of 16 different
operations, this number being chosen to mimic closely the 20
amino acids produced by the genetic code while keeping the number
of possible combinations manageably low. Some of the
instructions were neutral directions such as "skip the next
instruction". But others, if put together in exactly the right
combination, would allow a string of code to make a copy of
itself and insert this into a vacant slot within the stack. The
total number of instructions in each slot initially varied
between 1 and 25, so many slots contained duplicates.
Pargellis then asked the computer to process the instructions in
each memory slot, to mimic the biochemical activity of nucleic
acids. The program also contained a routine called "reaper" that
simulated the continual destruction and creation of new nucleic
acids in the primordial soup...
Most of the time, the computer routinely read through the random
babble of code. But occasionally it would move or copy pieces
of computer code from slot to slot. In 3 per cent of these
cases, these "mutations" gave rise to replicating strings of code
that could copy themselves into other positions in the stack
(Physica D, Vol 91, p.86)...."
I have a few preliminary comments:
1. Clearly, the "primordial soup" concept is active and well in
the academic community!
2. Pargellis appears to:
(a) start with meaningful genetic instructions,
(b) employ a mechanism within the computer for putting the
instructions together as strings,
(c) employ a processing routine to execute these instructions.
This seems to model a scenario which goes far beyond anything
that has been demonstrated as feasible for a primordial soup.
I don't want to miss the thrust of what Pargellis is doing - so
would value comment on this computer model (called Amoeba, by the
way). Any feedback would be appreciated.
Best wishes,
*** From David J. Tyler, CDT Department, Hollings Faculty,
Manchester Metropolitan University, UK.
Telephone: 0161-247-2636 ***