An Illustration of the Early Evolution of the Nervous System

A Cnidaria (Hydra) Model
     by J. Albert
(PhD advisor: G.Kampis)

Albert, J., 1999. Computational modeling of an early evolutionary stage of the nervous system. Biosystems 54, 77-90.
Albert, J. 1997:  Towards a Comprehensive A-Life Model of the Nervous System and Adaptive Behavior, Alife VII   full paper



"We found that if during the evolutionary process a kind of cell comes into being that is able to conduct
electrical stimuli - even in a rudimentary way - than this kind of cell can increase the adaptivity of the
behavior by itself without containing any specific information of how to organize the construction of this system"

"On the basis of these results we can say that a homogenous, diffuse conducting network -
which is probably similar to the ancestor of the nervous system - can be sufficient to control
the basic reactions of a simple living being to the environmental stimuli, which stands in harmony
with the results of physiological experiments."
 
"Summarizing the results: in a network of homogenous epithelial-like cells,  considered as the starting
point of nervous organization, the changes that adaptively influence the behavior are those that make
conductivity more efficient."



The Figures below show the construction of the model animal ("animat"),
the role of the skin (epithelial) cells in the early nervous system
and the behavior of a typical trained network of skin cells.

For more details, see the original publications.

Figure 1
Figure 3
Figure 4