Within any suitable framework of primitive automaton components
(CA or otherwise) the von Neumann architecture for
self-reproduction can generally give rise to (an infinity of)
infinite sets of self-reproducing automata. The automata
within any single such set are characterised as sharing a
particular ``constructing'' or ``decoding'' subsystem (a
``general constructive automaton''). This means that all the
automata within such a set share the same formal ``genetic
language''; this, in turn, means that they are connected by a
network of potential mutations. The latter was an important
and significant finding by von Neumann, as it established that
some, at least, of the conditions for the evolutionary growth
of automaton complexity can be met in such mechanistic
frameworks, within any single one of these von Neumann sets of
self-reproducers (
McMullin, 2000).
This note explores a further elaboration of these results,
based on the possibility of mutational pathways
between
(as opposed to
within) von Neumann sets; i.e., pathways
between automata implementing
different genetic
languages. Von Neumann himself considered this issue briefly,
but apparently discounted it
(
von Neumann, 1949, p. 86). By contrast, I
argue that it may be deeply significant for both natural and
artificial evolutionary systems.