Cell-Cell Channels, Viruses, and Evolution Via Infection, Parasitism, and Symbiosis toward Higher Levels of Biological Complexity

摘要

Between prokaryotic cells and eukaryotic cells there is dramatic difference in complex-ity which represents a problem for the current version of the cell theory, as well as forthe current version of evolution theory. In the past few decades, the serial endosymbi-otic theory of Lynn Margulis has been confirmed. This results in a radical departurefrom our understanding of living systems: the eukaryotic cell represents de facto "cells-within-cell." Higher order "cells-within-cell" situations are obvious at the eukaryoticcell level in the form of secondary and tertiary endosymbiosis, or in the male and fe-male gametophytes of higher plants. The next challenge of the current version of thecell theory is represented by the fact that the multicellular fungi and plants are, in fact,supracellular assemblies as their cells are not physically separated from each other.Moreover, there are also examples of alliances and mergings between multicellularorganisms. Infection, especially the viral one, but also bacterial and fungal infections,followed by symbiosis, is proposed to act as the major force that drives the biologicalevolution toward higher complexity.