Definition of Life

Herbert Martin Sauro hrs at aber.ac.uk
Tue Feb 8 15:13:44 EST 1994


As regards a definition of life I think we should move on from the usual
school boy/girl definition of 'growth, movement, etc...' and have something
more modern. The 'old' definition is sometimes sometimes known 
as Mrs Grem! (figure that out).

I think is this modern age we can think of life as being composed to two
components.

1) A set of instructions.
2) And a machine.

The machine has two unique properties, 

1) It can duplicate the instructions.
2) It can read the instructions and carry them out. The essential part is
that execution of the instructions is actually to make a copy of itself.

We have here then a vicious circle, each part of the cycle dependent on
the other.

Once a duplicate of the instructions and the machine has been made a new
copy of the life form has been created. The other force at work which gives
the life forms a lot more spice is that the copying process is not
error free, and thus mutations are introduced which under the force of
selection means that the life form experiences evolution.

The great question of course is how on earth (excuse the pun) did the
cycle of dependence between the machine and the set of instructions 
first get started?

Hope this helps, perhaps it will be too clinical for some people.

Herbert sauro



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