Introduction come the ArchaeaLife"s extremists. . . The Domain Archaea wasn"t well-known as a major domain that life till quiterecently. Till the 20th century, many biologists considered all living thingsto be classifiable as either a tree or an animal. Yet in the 1950s and also 1960s,most biologists came to the realization the this system failed come accomodatethe fungi, protists, and also bacteria. Through the 1970s, a mechanism of five Kingdomshad involved be accepted as the model by which all life things could beclassified. At a more basic level, a distinction was made between theprokaryotic bacteria and also the foureukaryotic kingdoms (plants,animals, fungi, & protists). The difference recognizes the usual traits thateukaryotic biology share, such together nuclei, cytoskeletons, and internal membranes.The scientific ar was easy to understand shocked in the late 1970s through thediscovery of one entirely brand-new group of organisms -- the Archaea. Dr. Carl Woeseand his colleagues at the college of Illinois were researching relationshipsamong the prokaryotes making use of DNA sequences, and found the there were twodistinctly different groups. Those "bacteria" that lived at high temperaturesor produced methane clustered with each other as a group well far from the usualbacteria and also the eukaryotes.Because that this vast difference in hereditary makeup, Woese proposed the life bedivided into three domains: Eukaryota, Eubacteria, and Archaebacteria.He later made decision that the term Archaebacteria to be a misnomer, and also shortened itto Archaea. The 3 domainsare shown in the illustration over at right, i beg your pardon illustrates also thateach group is really different native the others.Further work has revealed added surprises, i beg your pardon you deserve to read around onthe other pages of this exhibit. It is true that most archaeans don"t lookthat various from bacteria under the microscope, and also that the extremeconditions under which many species live has actually made them an overwhelming to culture,so their distinct place amongst living organisms long went unrecognized.However, biochemically and genetically, they space as different from bacteria asyou are. Although countless books and also articles still describe them together "Archaebacteria", that term has actually been abandoned because they aren"t bacteria -- they"re Archaea.
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Sources:T. D. Brock, M. T. Madigan, J. M. Martinko, & J. Parker. 1994. Biologic of Microorganisms, 7th ed. (New Jersey: Prentice Hall).W. Ford Doolittle. 1992. What are the archaebacteria and also why space they important? Biochemical culture Symposium 58: 1-6.G. E. Fox, L. J. Magrum, W. E. Balch, R. S. Wolfe, & C. R. Woese, 1977. Category of methanogenic bacteria through 16S ribosomal RNA characterization. Proc. Natl. Acad. Sci. USA 74: 4537-4541.K. Horikoshi & W. D. Provide (eds.). 1998. Extremophiles -- Microbial Life in Extreme atmospheres (New York: Plenum).John L. Howland. 2000. The surprising Archaea (New York & Oxford: Oxford university Press).M. T. Madigan & B. L. Marrs, 1997. Extremophiles. Scientific American (Apr): 82-87.C. R. Woese, 1981. Archaebacteria. Scientific American (Jun): 98-122.C. R. Woese & G. E. Fox, 1977. Phylogenetic framework of the prokaryotes domain: The main kingdoms. Proc. Natl. Acad. Sci. USA 74: 5088-5090.