Biology Reference
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He showed that computing machines are fragile to perturbation and are designed
to crash when errors occur. Living systems cannot afford to stop, for it would be a
point of no return. Instead, they have evolved the following:
a. The ability to detect and localize the site of the error, process the afferent information on
the nature of the error, and generate instructions to correct the error or repair the damaged
cell or supracellular structure, all in the controller.
b. The robustness to function normally, even under conditions of perturbation.
Living systems evolved many components whose purpose is the system reliabil-
ity. They are highly integrated, and they can function normally even after errors, if
those errors are perceived as negligible.
In his theory, von Neumann posited that living organisms are very complex aggre-
gates of their elementary parts, and from a thermodynamic perspective, they are
highly improbable structures. “That they should occur in the world at all is a mir-
acle of the first magnitude; the only thing which removes, or mitigates, this mira-
cle is that they reproduce themselves” ( von Neumann, 1966 ). He observed that a
theoretical difficulty arises when it comes to the reproduction of artificial automata
(self-replicating machines): “one gets a very strong impression that complication, or
productive potentiality in an organization, is degenerative, that an organization which
synthesizes something is necessarily more complicated, of a higher order, than the
organization it synthesizes.”
This is an essential difference between living organisms and artificial automata.
But, according to von Neumann, the complexity is degenerative only below a certain
low level. If the complexity is crudely measured by the number of components of
a system, it is possible, he reasoned, to build an automaton of such a high level of
complexity that can “construct other automata of equal or higher complexity.” These
machines would compete in shared environments, would be subject to natural selec-
tion, and may evolve similarly to living systems. Suggestions are made that in order
to minimize effects of perturbations during the assemblage of the universal construc-
tor, subsystems may be needed to construct automaton's “workplace.” The universal
constructor in the workplace will pick up parts and assemble them into a copy of
itself in sequential cycles of self-reproduction.
The self-reproduction of the universal constructor can be seen as an artificial
analog for unicellulars, which produce their twin organism in a complete form
capable of independent life and self-reproduction. This holistic mode of self-
reproduction does not fit into the model of the development of multicellular animals
and plants, where parents control only part of the development of offspring rather
than the whole development. Interestingly, William R. Buckley recently came up
with an alternative model of self-reproduction reminiscent of the development of
multicellular animals based on the production of gametes (eggs and sperm cells).
According to his model, the universal constructor builds not a copy of itself, but
rather an incomplete structure capable of producing its parts, and assembles them
into a complete functioning machine capable of self-reproduction. In clear distinc-
tion from von Neumann's machine, where the daughter machine becomes functional
only after it is fully assembled by the mother machine, Buckley's model has the
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