Biology Reference
In-Depth Information
hierarchy which eventually would bring the whole factory to a standstill. Clearly
the problem cannot be solved by adding extra levels of fabrication. Is it possible
to internalise this fabrication process so as to make the system completely
autonomous (closed) with respect to fabrication, i.e., self-fabricating? (Note that
the factory will always remain open to material cause through its dependence
on input A from outside.) Consider the arrangement in Fig. 4e. One conceivable
way in which the system can rid itself from the necessity for level E and thereby
become self-fabricating is if a fabricator lower down in the fabrication hierarchy
is able to manufacture D: In Fig. 7a, C manufactures D from B, while in Fig. 7b
B manufactures D from C. Another possibility is that D be able to fabricate
itself from either B (Fig. 7c) or C (Fig. 7d).
However, as the following argument shows, there is another incipient regress
hidden in our factory: The problem of insufficient numbers of machines. If
all the individual steps in all the levels of the fabrication hierarchy are to be
performed by a dedicated specific machine, then it is impossible to make the
factory self-fabricating using the organisations in Fig. 7. A very simple numerical
example demonstrates the problem: Let the set of building blocks B have two
members, each fabricated from A in two steps. The set of specific fabricators C
therefore needs four members. Let each member of C be made from B in two
steps, each step being facilitated by a specific member of the set of D, which
therefore needs eight members. If each member of D again needs two specific
fabricators then the next level E (Fig. 5) would have contained 16 fabricators.
However, in Fig. 7a and b these 16 functions must be performed by members of
either B or C. On could conceive of adding extra members to C, but then they
would also need to be made from B, which implies that D must be even larger
than before, which in turn implies even more C, and so on. The same holds for
Fig. 7b, but here we also require the members of B to also be fabricators. The
organisations in Fig. 7c and d lead to the same problem. Clearly this option is
a logical impossibility. Another way out would be to require members of B or
C to become multifunctional. However, even in this simple case it means that
A
C
A
C
(a)
(b)
B
D
B
D
A
C
A
C
(c)
(d)
B
D
B
D
Figure 7
Potential self-fabricating organisations.
