Gallertoide
Gallertoide is the name given by the representatives of the so-called Frankfurt evolutionary theory for a (hypothetical) reconstruction of the structure of the first multicellular animals , which could have represented the starting point for the evolution of the entire animal kingdom . The (likewise hypothetical) anatomy and histology of the Gallertoide have been "reconstructed" within the framework of research work on the Frankfurt theory of evolution on the basis of construction morphological considerations and histological investigations of recent organisms .
The gallertoid hypothesis
Before the development of the gallertoid theory, most theories for the origin of the first multicellular animals were based on hollow spherical representatives, into which digestive spaces folded in the course of evolution. These theories were presented in analogy to the gastrulation process in embryonic development, without taking into account that, strictly speaking, this cannot be compared with an evolutionary process that takes place over many generations. In particular, the slow folding of canals requires internal stabilization by connective tissue. The scientific content and the innovation of the gallertoid theory is particularly to be understood against this background.
The structure of the gallertoide body made of connective tissue ( collagen ) with cells embedded in this fiber network can be recognized as a typical construction for the animals . In addition, all fibrous structures are enclosed by an epithelium , a dense cell layer, in order to separate the fiber network from the surrounding medium (water). The gallertoids must have been small animals a few millimeters in size, with different body shapes and criss-crossed by a more or less dense system of canals. These channels were lined with a ciliated epithelium and served for food intake . Particles were transported through the channels and taken up by the cells and the usable components were then distributed in the body.
Gallertoide is the first multicellular animal to combine all of the structural components typical of animals. Based on this construction, the main evolutionary lines of the animal kingdom can finally be reconstructed. To this day there are organisms that are close to the histological structure of the gallertoide, the ctenophores .
The creation of the Gallertoide is acc. of the Frankfurt evolution theory as a process of internal compartmentalization and described. Fibers ( polysaccharides and polypeptides ) were initially stored in polysaccharides and polypeptides as energy stores in multinucleated single cells , the body of which is traversed by a broad system of channels and tubes in the endoplasmic reticulum . The storage of fiber proteins changes the mechanical properties of the body, it is solidified, the consistency acquires gelatinous, gel-like properties. This mass supported and stabilized the body of the early polynuclear unicellular organisms and the organism could take on larger forms. The surrounding cytoplasm is stretched and enclosed by the walls of the endoplasmic reticulum . Since these walls have the same structure as the outer cell membrane - more precisely: the endoplasmic reticulum contains building blocks of the cell membrane - a multicellular body structure with a syncytial structure was created.
literature
- W. Oschmann, M. Grasshoff, M. Gudo: The early evolution of the planet earth and the origin of life. In: Senckenbergiana Lethaea , Volume 82, No. 1, 2002, pp. 285-294.
- M. Grasshoff, M. Gudo: The evolution of the coelenterates I. Gallertoid corals and octocorals. In: Natur und Museum , Volume 128, No. 5, 1998, pp. 129-138.
- K. Bonik, M. Grasshoff, WF Gutmann: The evolution of animal constructions: I. Problem situation and premises, II. Multi-cellular cells and the evolution of gallertoide. In: Natur und Museum , Volume 106, No. 5, 1976, pp. 129-143.
Individual evidence
- ^ M. Grasshoff, M. Gudo: The origin of metazoa and the main evolutionary lineages of the animal kingdom - The gallertoid hypothesis in the light of modern research. In: Senckenbergiana Lethaea , Volume 82, No. 1, 2002, pp. 295-314.
- ↑ M. Grasshoff, M. Gudo: The evolution of the coelenterates I. Gallertoid corals and octocorals. In: Natur und Museum , Volume 128, No. 5, 1988, pp. 129-138.
- ↑ M. Grasshoff, M. Gudo: The evolution of animals. Poster in DIN A1 format, 4th edition, Stuttgart (Schweizerbart'sche Verlagbuchhandlung) 2007.