An proof is presented that gene regulatory networks (GRNs) based solely on protein transcription factors (TFs) cannot control the development of complex multicellular life. Hence, GRNs cannot explain the evolution of multicellular life in the Cambrian Explosion. Networks are based on an addressing system which is used to construct network links. The links utilize the addresses to connect two or more linked nodes in the network. The more complex the network the greater the number of links and the larger the required address space. Addresses are formed by combinations of basic units. It has been assumed that combinations of protein transcription factors (TFs) generate a large enough address space to form gene regulatory networks that are complex enough to control the development of complex multicellular life. We prove that TFs do not have sufficient combinatorial power to serve as the basis of an addressing system for regulatory control of genomes in the development of URLanisms. More generally, there are inherent bounds on the complexity of control networks based solely on transcription factors. I show that given n transcription factor genes in a genome and address combinations of length k then there are at most n/k k-length TF-addresses in the address space. The complexity of embryonic development requires a corresponding complexity of control information in the cell and its genome. Therefore,  different addressing system must exist to form the complex control networks required for complex control systems.  These new developmental control networks are called CENES (for Control genes). The evolution of CENEs made the Cambrian Explosion possible. Their code is universal (modulo syntax) in the genomes of all multicellular life.
A proof is presented that gene regulatory networks (GRNs) based solely on transcription factors cannot control the development of complex multicellular life. GRNs alone cannot explain the evolution of multicellular life in the Cambrian Explosion. Networks are based on addressing systems which are used to construct network links. The more complex the network the greater the number of links and the larger the required address space. It has been assumed that combinations of transcription factors generate a large enough address space to form GRNs that are complex enough to control the development of complex multicellular life. However, it is shown in this article that transcription factors do not have sufficient combinatorial power to serve as the basis of an addressing system for regulatory control of genomes in the development of URLanisms. It is proven that given n transcription factor genes in a genome and address combinations of length k then there are at most n/k k-length transcription factor addresses in the address space. The complexity of embryonic development requires a corresponding complexity of control information in the cell and its genome. Therefore, a different addressing system must exist to form the complex control networks required for complex control systems. It is postulated that a new type of network evolved based on an RNA-DNA addressing system that utilized and subsumed the extant GRNs. These new developmental control networks are called CENES (for Control genes). The evolution of these new higher networks would explain how the Cambrian Explosion was possible. The architecture of these higher level networks may in fact be universal (modulo syntax) in the genomes of all multicellular life.
R
An
A
R
protein transcription factors (TFs)
transcription factors
R
Hence, GRNs
GRNs alone
R
an addressing system which is
addressing systems which are
R
links utilize the addresses to connect two or more linked nodes in the network. The more
more
D
Addresses are formed by combinations of basic units.
R
protein transcription factors (TFs)
transcription factors
R
gene regulatory networks
GRNs
R
We prove that TFs
However, it is shown in this article that transcription factors
R
More generally, there are inherent bounds on the complexity of control networks based solely on transcription factors. I show
It is proven
R
TF-addresses
transcription factor addresses
A
a
A
It is postulated that a new type of network evolved based on an RNA-DNA addressing system that utilized and subsumed the extant GRNs.
R
CENEs made
these new higher networks would explain how
R
possible. Their code is
was possible. The architecture of these higher level networks may in fact be