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We start with the most primitive animals. Unlike plants, they have an apparatus that allows them to take actions of their own and to control those actions through irritation of nerve cells. Take a hydra. It has two layers of cells containing muscle fibers which contract when irritated, and nerve cells (receptors) which can irritate and pass irritation to muscle fibers. If a hydra is pricked with a needle it squeezes itself into a tiny ball. The emergence of this apparatus is a metasystem transition (MST) from the stage of primitive plants where there are no self-induced actions. This MST is defined by the formula:

cell-irritation = control of actions

Indeed, we see in the hydra all elements of the control scheme. The "representation" corresponds to the receptors in the ectoderm which get irritated and pass irritation to muscle fibers; The "agent" stands for the muscle fibers, which act when irritated.

Copyright© 2003 Principia Cybernetica - Referencing this page

V. Turchin,

Apr 23, 2003 (modified)
Sep 1991 (created)


Metasystem Transition Theory

The History of Evolution

Cognitive Evolution (stages)

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