The organism as a hydrostatic soft body
As stated above, organisms are hydrostatic soft bodies in the mechanical sense because the chemical processes typical for life take place only in aqueous solutions and are held together by a flexible covering. With regard to their change, we are only talking about „The Evolution of Hydraulic Constructions“ (W.F. Gutmann 1995).
With a uniform membrane, such a body assumes the form of a sphere because of internal liquid pressure. Any other form must be generated against the spherical shape with fibers and with rigid parts. This applies for technical devices just as it does for organisms. Whatever materials the covering and the filling consist of, the cells of the organisms, the fire brigade hose with its liquid fillings, the rice and sugar sacks with their granulate fillings, and the bicycle tube and soap bubbles with their air fillings all constitute the same structural type: the architect Frei Otto called it the “pneu.” Only on this level it is possible to argue about the change of the various animal body designs.
In the specific case of animals, the construction materials are cells and collagen fibers (elastic or with tensile strength) that lie in the more or less viscous extracellular matrix (ECM). Both are specialized in a variety of tasks, and accordingly assume different forms.
The explicitly technical perspective will be illustrated with a specific case: we describe the earthworm as a hydrostatic body with right/left symmetrically and serially arranged fluid spaces (zoological: the coeloms) and transverse walls that act as tension belts; lengthwise, transverse and ring-shaped fibers with tensile strength (collagen fibers) and those that are contractile (muscles). A continuous duct (intestine), an outer layer of crossed collagenous fibers (cuticle), and we include as many details as we find necessary.
We then speak and argue only about this body design and how it works, i.e. how it works within itself and towards the surrounding world, its ecological relationship, and finally we speak about its possibilities to gradually change.
To ascertain the basic lines of the animal kingdom, we reconstruct the primordial animal as the simplest possible construction made up of the two structural components: cells and gel-like stored collagen fibers. Subsequently, the path is to be reconstructed on which various body designs were able to arise. The animals from a distant past can only be depicted as design types from which the animal types known to us as fossils or living today emerged.
In fact, the animals actually existing today and the fossil animals are the starting point of our considerations: using them, we examine how the design type is to be described, as shown with the example of the earthworm above. The duality of the approach is typical for all historical research: one reconstructs a process in the past on the basis of current knowledge; the current subject is thus both the starting point and the end point of the scientific procedure.
Theory and graphical visualization
Using the terms of the philosophy of science, these reconstructions are models for evolutionary processes. Only they can be developed, discussed and, where appropriate, falsified by proving an error. The description and the comparison of animals actually existing today or fossil, and the discussion about them, always remains at the level of naturalism and cannot reach the level of the dynamic of transformations.
This working method and its results, which were published in numerous papers, are comprised and visualized in the graphics of the poster. That is why there are only design drawings for the evolutionary lines in the center. Along the edge, real animals are depicted whose body design we have studied and taken as the basis for our reconstruction; the real animals are in turn the result of the reconstructed evolutionary processes.
