cycle goes on and on. This can go on for any number of stages; the hope is
that eventually, among the strands which are present at some point, there
will be found two copies of the original strand (one of the copies may be, in
fact, the original strand).The Central Dogma of TypogeneticsTypogenetical processes can be represented in skeletal form in a diagram
(Fig. 90).
enzymes
translation ( ) typographical
via ribosomes '\ manipulationFIGURE 90. The "Central Dogma of
Typogenetics": an example of a "Tangled
Hierarchy".
strandsThis diagram illustrates the Central Dogma of Typogenetics. It shows how
strands define enzymes (via the Typogenetic Code); and how in turn,
enzymes act back on the strands which gave rise to them, yielding new
strands. Therefore, the line on the left portrays how old information flows
upwards, in the sense that an enzyme is a translation of a strand, and
contains therefore the same information as the strand, only in a different
form-in particular; in an active form. The line on the right, however, does
not show information flowing downwards; instead, it shows how new infor-
mation gets created: by the shunting of symbols in strands.
An enzyme in Typogenetics, like a rule of inference in a formal system,
blindly shunts symbols in strands without regard to any "meaning" which
may lurk in those symbols. So there is a curious mixture of levels here. On
the one hand, strands are acted upon, and therefore play the role of data
(as is indicated by the arrow on the right); on the other hand, they also
dictate the actions which are to be performed on the data, and therefore
they play the role of programs (as is indicated by the arrow on the left). It is
the player of Typogenetics who acts as interpreter and processor, of
course. The two-way street which links "upper" and "lower" levels of
Typogenetics shows that, in fact, neither strands nor enzymes can be
thought of as being on a higher level than the other. By contrast, a picture
of the Central Dogma of the MIU-system looks this way:
rules of inference! (typ"grapMcal manipu"'"""J
stringsIn the MIU-system, there is a clear distinction of levels: rules of inference
simply belong to a higher level than strings. Similarly for TNT, and all
formal systems.
Self-Ref and Self-Rep^513