[Taxacom] Mayr vs. Woese debate over Metabacteria/Archaebacteria (as a third Empire/Domain?)

[Kenneth Kinman]

Dear All,

      (1)  In his paper entitled "Two empires or three?", Ernst Mayr seems to have correctly assessed the inadvisability of a Three Domain/Empire classification, probably best summarized by this paragraph:

      "Woese baptized the newly discovered organisms archaebacteria, thinking they would have been the first organisms on the newly habitable earth because of their ability to live in an anoxic atmosphere and in hot springs, sulfur springs (thermo-acidophiles), brines (halophiles), and other unusual habitats, presumably common on the new earth. However, when it later appeared probable that they were not the most ancient bacteria and might have a common stem with the eubacteria, Osawa and Hori (7<http://www.pnas.org/content/95/17/9720.full?ijkey63a0329305db671f86ee684020b2ee3d6a883f&keytype2=tf_ipsecsha#ref-7>) suggested replacing the misleading name archaebacteria by metabacteria. Neither Woese (8<http://www.pnas.org/content/95/17/9720.full?ijkey63a0329305db671f86ee684020b2ee3d6a883f&keytype2=tf_ipsecsha#ref-8>) nor other microbiologists accepted this change of name. Instead Woese renamed them Archaea, retaining the inappropriate component—archae—and discarding the informative component—bacteria, which revealed their prokaryote nature."


      (2) In his response to this, Woese concluded: "The prokaryote–eukaryote dichotomy. This dichotomy, which Dr. Mayr proposes to reinstitute, is a failed taxonomic theory that was never recognized as theory, and so tested in a timely fashion, with the consequence that it has adversely affected the development of biology, especially microbiology, in the latter half of this century."


      (3) It seems to me (and others) that it was actually the Three Domains (an unfortunate, warmed over version of Woese's discredited Three Urkingdoms which he proposed 13 years earlier), both of which turned out to be simplistic and being what actually "adversely affected the development" of microbiology in the latter half of the 20th Century.  Cavalier-Smith on the other hand admits his occasional mistakes, incorporates new information, and moves on. The importance of Archaebacteria (a.k.a. Metabacteria) is actually their close relationship to Eukaryota, and is far too young to have anything to do with the origins of life.  The still unanswered question is whether Archaebacteria (a.k.a. Metabacteria) is the sister group of Empire Eukaryota (as Cavalier-Smith believes), or if the sister group of Eukaryota is actually a particular subgroup within Archaebacteria (different subgroups being suggested by different researchers as the sister group).


<http://www.pnas.org/content/95/17/9720.full?ijkey63a0329305db671f86ee684020b2ee3d6a883f&keytype2=tf_ipsecsha>http://www.pnas.org/content/95/17/9720.full

http://www.pnas.org/content/95/19/11043.full

                 ----------------Ken Kinman