[ Follow Ups ]
Posted by pietro ramellini on October 27, 1999 at 12:09:20:
In Reply to: The program God posted by Pierre on October 10, 1999 at 07:52:56:
Traditionally it has been made a distinction
between the terms 'creator' and 'demiurge'. The creator creates something from
nothing, while the demiurge arranges, orders, sets in order something having
preexisting matter, space and ideas available. So that, your hypothesis would
become, I think, that the genetic program is a demiurge.
Now, let's look at the hypothesis. What sort of demiurge should be the genetic
program? What should it order?
Firstly, it is called 'program' a system of instructions necessary (but
eventually not sufficient) to perform an algorhytm. Biologically, the term
knows a metaphorical utilization which is not always easy to clarify; so, could
you give us the meaning you use?
As far as I can see, three main definitions have been proposed for 'program':
- a system of generic information or data
- a system of instructions necessary to synthesize protids
- a system of regulation of the energy flow which crosses a living entity
If we specify that it is a 'genetic program', we restrict the field of data,
instructions, regulation signals to those related to polynucleotides (DNAs,
RNAs or both; this choice should be declared).
In any case, we can show that the genetic program is not a condition necessary
and sufficient to set in order a living entity, in the sense of starting its
life, through this experiment. Put in a test-tube a bacterial growth medium,
with all the substances necessary to bacterial life (or even all the organules
of a bacterial cell), and the energy necessary for the construction of a
bacterial cell, in the form of potential chemical energy. Then, put in the tube
a bacterial chromosome, the material substrate of the genetic program. You will
realize that nothing happens or, better, no bacterial life takes place, while
the substances begin to decade towards the termodynamic equilibrium: the
program fails the goal of ordering the bacterial life.
On the contrary, try this experiment. Put in a test-tube a medium containing an
enucleated human egg cell. Then inject into it the nucleus of a human sperm
cell. Soon you will watch the beginning of the embryonal development. What's
the difference? The fact is that in this case, in addition to the genetic
nuclear program, other necessary conditions have been satisfied, for instance
the correct topological arrangement of the substances and organules.
So that, the genetic program can be seen as a condition necessary, but not
sufficient, to "explain every (biological) observed structure in a
satisfying manner".