23 pp.
23 pp.
| 1759 K 23 pp. | |
| View Document | ||
| Title | The Winds of (Evolutionary) Change: Breathing New Life into Microbiology | |
| Author(s) | Olsen, G. J. ; Woese, C. R; Overbeek, R. A. | |
| Publication Date | March 1996 | |
| Report Number | MCS--P402-1293 | |
| Unique Identifier | ACC0217 | |
| Other Numbers | Legacy ID: DE96007630; OSTI ID: 205047; NSF Grant DIR 89-57026 | |
| Research Org | Argonne National Laboratory (ANL), IL (United States); University of Illinois, Urbana, IL (United States). Department of Microbiology | |
| Contract No | W-31109-ENG-38 | |
| Sponsoring Org | USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States); National Aeronautics and Space Administration, Washington, DC (United States) | |
| Subject | 55 Biology And Medicine, Basic Studies; 09 Biomass Fuels; Microorganisms; Biological Evolution; Species Diversity; Ribosomal RNA | |
| Related Web Pages | The Discovery of Archaea, the 'Third Branch of Life', and Its Impacts | |
| Abstract | To date, over 1500 prokaryotes have been characterized by small subunit rRNA sequencing and molecular phylogeny has had an equally profound effect on our understanding of relationship among eukaryotic microorganisms. The universal phylogenetic tree readily shows however how artificial the strong distinction between the eukaryote and prokaryotes has become. The split between the Archaea and the Bacteria is now recognized as the primary phylogenetic division and that the Eucarya have branched from the same side of the tree as the Archaea. Both prokaryotic domains would seem to be of thermophilic origin suggesting that life arose in a very warm environment. Among the Archaea, all of the Crenarchaeota cultured to date are thermophiles, and the deepest euryarchaeal branchings are represented exclusively by thermophiles. Among the Bacteria, the deepest known branchings are again represented exclusively by thermophiles, and thermophilia is widely scattered throughout the domain. The Archaea comprise a small number of quite disparate phenotypes that grow in unusual niches. All are obligate or facultative anaerobes. All cultured crenarchaeotes are thermophilic, some even growing optimally above the normal boiling temperature of water. The Archaeoglobales are sulfate reducers growing at high temperatures. The extreme halophiles grow only in highly saline environments. The methanogens are confined to a variety of anaerobic niches, often thermophilic. The Bacteria, on the other hand, are notable as being the source of life`s photosynthetic capacity. Five kingdoms of bacteria contain photosynthetic species; and each of the five manifests a distinct type of (chlorophyll-based) photosynthesis. | |
| 1759 K 23 pp. | |
| View Document | ||
