Bikonta

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The division of living beings into systematics is a continuous subject of research. Different systematic classifications exist side by side and one after the other. The taxon treated here has become obsolete due to new research or is not part of the group systematics presented in the German-language Wikipedia.

The term Bikonta covers a certain group of living organisms with a cell nucleus ( eukaryota ). All bikonta have (or probably originally) have bicontal cells . Bicontal cells are cells with two flagella .

The large groups of Archaeplastida (including red algae and terrestrial plants ), Excavata (including Euglenozoa with the well-known eye animals ), Rhizaria (including foraminifera and radiation animals ), Chromalveolata (including brown algae , diatoms and eyelashes ) and perhaps (uncertainly) also belong to the Bikonta flagellates belong to Apusozoa . However, it is not entirely undisputed whether the Bikonta actually all descend from a last common ancestor, i.e. whether they form a monophylum . Because of this uncertainty, the Bikonta taxon is currently not included in the comprehensive systematics of eukaryotes of the German-language Wikipedia.

All other eukaryota are not bikonta, but unikonta . The Unikonta include, on the one hand, the Amoebozoa , the majority of which look like amoeba , and, on the other hand, the group of push flagella ( Opisthokonta ). The Opisthokonta are further subdivided, especially into the large groups of animals (Animalia) and chitin mushrooms (real mushrooms, Fungi). In contrast to the Bikonta, the Unikonta taxon is now relatively well documented.

In addition to the original number of flagella, Bikonta and Unikonta differ in further molecular and cell biological characteristics.

Individual evidence

  1. ↑ T. Cavalier-Smith: The phagotrophic origin of eukaryotes and phylogenetic classification of Protozoa. In: International Journal of Systematic and Evolutionary Microbiology. 52, 2002, pp. 297-354.
  2. ^ T. Cavalier-Smith: Megaphylogeny, cell body plans, adaptive zones: causes and timing of eukaryote basal radiations. In: J. Eukaryot. Microbiol. 56, 2009, pp. 26-33.
  3. ↑ D. Moreira, S. vd Heyden, D. Bass, P. López-García, E. Chao, T. Cavalier-Smith: Global eukaryote phylogeny: Combined small- and large-subunit ribosomal DNA trees support monophyly of Rhizaria, Retaria and Excavata. In: Mol. Phylogenet. Evol. 44, 2007, pp. 255-66.
  4. ^ A b I. B. Rogozin, MK Basu, M. Csürös, EV Koonin: Analysis of Rare Genomic Changes Does Not Support the Unikont – Bikont Phylogeny and Suggests Cyanobacterial Symbiosis as the Point of Primary Radiation of Eukaryotes. In: Genome Biology and Evolution. 1, 2009, pp. 99-113. doi: 10.1093 / gbe / evp011
  5. ^ A. Stechmann, T. Cavalier-Smith: The root of the eukaryote tree pinpointed. In: Current Biology. 13, 2003, pp. 665-666.
  6. ^ TA Richards, T. Cavalier-Smith: Myosin domain evolution and the primary divergence of eukaryotes. In: Nature. 436, 2005, pp. 1113-1118.
  7. ^ A. Stechmann, T. Cavalier-Smith: Rooting the eukaryote tree by using a derived gene fusion. In: Science. 297, 2002, pp. 89-91.
  8. ↑ F. Burki, K. Shalchian-Tabrizi, M. Minge, Å. Skjæveland, SI Nikolaev, KS Jakobsen, J. Pawlowski: Phylogenomics Reshuffles the Eukaryotic Supergroups. In: PLoS ONE 2. 2007, p. E790