Evolution of Vertebrate Locomotory Systems

Abstract

Admiring nature for its seeming perfection, at least when one of its products are humans themselves, many concepts are based on „learning from nature“. Biomimicry, where the mechanical properties and control architectures in animals are more or less copied, or bionics, where biological structures are rebuilt in technical devices are only two examples of such concepts. But, there is a striking difference between biological and technical structures defined as solutions to external demands. Whereas technical structures can be and are created de novo, biological structures are always the result of a permanent and ongoing historical process. They are carrying their evolutionary burden, and by mere logic their ability to adapt to actual demands can only be perfect, if the past and recent functional requirements are identical. Seilacher (1970) drew a triangle in which he named the three vertices: „historisch-phylogenetischer Aspekt“, „ökologisch-adaptiver Aspekt“ and „bautechnischer Aspekt“ (Figure 1). Gould (2002) called „these idealized end-members“ „historical“, „functional“, and „structural“ (p. 1052), and the whole thing an „aptive triangle“. „Structural“ includes two aspects: first, the „immediate and deterministic consequences of the physical properties of matter and the dynamical nature of forces“ (ibid. p. 1054), a view which is familiar to all morphologists since D’Arcy Thompson (1917). The second aspect are the „spandrels of San Marco“ (Gould and Lewontin, 1979), which have been introduced into biology to point to features arising by nonadaptive processes, or as simple consequences of design and growth criteria (technical architecture).

First, Martin Fischer wants to thank very much Teresa Zielinska and Friedrich Pfeiffer for inviting him to Udine to a phantastic meeting. Roy Ritzmann, with whom an exciting cooperation started there, helped with his critical comments and language polishing to improve the manuscript. We are grateful to all members of the Jena „Locomotion group“ who helped with their enthusiasm. ideas, and practical help. We thank Gertrud Klauer for focussing our view on the importance of sensory structures. The work was granted by the Deutsche Forschungsgemeinschaft (DFG) (Innovationskolleg „Bewegungssysteme“ Teilprojekte A1 and B1, and Schwerpunktprogramm „Autonomes Laufen“) and Berufsgenossenschaft Gaststätten und Nahrungsmittel (BGN) through the Kompetenzzentrum für Interdisziplinäre Prävention (KIP) at Jena.