Rise of the Animal Kingdom and Epigenetic Mechanisms of Evolution - Building the Most Complex Structure on Earth - page 259

Eumetazoans are hierarchical systems with several distinct but structurally inte-
grated and functionally coordinated levels of organization at the:

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molecular level, with genes and all other molecules that make up a cell;

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cell level, with organelles, including chromosomes, centrosomes, cytoskeleton, and cell
membrane;

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tissue level;

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organ level;

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systemic level.

Each level of organization has its own control, but the hierarchical character of
the control system requires the coordination of control at different levels. In this
interaction and coordination, a relationship is established between the control lev-
els, in which lower levels of control, including genomic control, are subordinate to
higher levels of control. At the top of the hierarchy is the systemic control that inte-
grates and coordinates the function of all the lower level controls. Anticipating the
modern concept of systems biology, in the context of the emergence of phenotype, as
early as 1939, Austrian biologist Paul A. Weiss (1898-1989) pointed out that “phe-
notypes, and the mechanisms that underlie them, depend on, and subordinate to, the
law which rules the complex as a unit” (Crews et al., 2012).
The control system in animals (sponges excluded) is an ICS, which epitomizes
the holistic nature of animals.
There is no general theory of control systems in animals, plants, or unicellulars.
Yet the discipline of physiology tells us that all the vital functions of animals (blood
circulation, excretion, digestion, reproduction, endocrine functions, behavior, etc.)
are under neural control with the brain as the controller of the control system. The
study of the functions of living organisms is, in fact, the science of control systems
for living organisms. Animal behavior too is centrally determined by the CNS and
empirical evidence shows that life histories and their evolution in animals are deter-
mined by the CNS. New in this ICS hypothesis is that it additionally attributes the
CNS a controlling role in the development of animal morphology. In Chapter 3,
more than adequate evidence demonstrating that the CNS controls the development
of animal morphology up to adulthood is presented ( Cabej, 2005, 2008, 2012 ).
That the ICS works to restore the normal state of the system implies that it
“knows” the norm of the immense number of variables at the molecular, cellular,
and supracellular levels. In many cases, it is empirically demonstrated that this
“knowledge” is coded in the form of established set points in the CNS (see page 16,
Homeostasis , and page 79, Epigenetic Information and Signal Cascades ).
The nervous system's omnipresence and its immense computational capabilities
allow it to monitor the homeostasis (in the broadest meaning of the word) via intero-
ceptors and exteroceptors, which afferently transmit the data on the various param-
eters of the system to the CNS. By processing these data, the CNS detects deviations
from the norm by comparing the actual data with the norm and then sending instruc-
tions for restoring the normal state to relevant regions of the body. Thus, the CNS
serves as the controller of the ICS in animals.
Herein I outline the model of the ICS in eumetazoans, a top-down model, in