[Taxacom] Eubacteria and Archaebacteria

[Kenneth Kinman]

Dear All, 
      I was just watching a rerun of the 2009 film
"Yellowstone: Land to Life" on PBS. Enjoyable (especially compared to a
lot of other stuff on television). However, I was disturbed that it
continues to repeat the unfortunate impression that Archaebacteria
("Archaea") are the most primitive forms of life on Earth, by stating:
"The beginnings of life on earth--single-celled microoranisms like
Archaea--first emerged in acidic hot springs like those at Yellowstone." 
      Give me a break!!!   Even IF (and that is a big IF),
Archaebacteria are the most primitive life forms on Earth, many, many
Archaebacteria are mesophilic or even psychrophilic. The idea that they
arose in hot springs at all (much less highly acidic ones) or even
around "black smokers" around deep-ocean spreading sites, is absurd from
a physico-chemical standpoint.    
       If you don't like Darwin's "warm little pond", I
would recommend considering extremely cold (near freezing) water as more
likely conditions under which early life arose. It certainly makes a lot
more sense than a thermophilic cauldron (acidic or not).               
        In any case, I continue to be impressed by the
work of Thomas Cavalier-Smith on the subject of life's origins, and that
Archaebacteria are actually a highly derived group evolving from
Posibacteria, which in turn evolved from the even older Negibacteria.
It made sense when I read his ideas back in the late 1980s, and it makes
even more sense now.            
      It is disturbing that PBS programs (and thus probably many
teachers) are indoctrinating their students with the idea that
"Archaebacteria" are really archaic compared to Eubacteria.  Thus they
too often give less emphasis to the far more important story, that an
early "archaebacterium" no doubt was the host cell to the first
Eukaryote.  My biggest quibble with Cavalier-Smith is only the timing of
that event---he says less than a billion years ago, while I believe it
happened more like 2 billion years ago.  Either way, it almost certainly
happened long after the origin of Eubacteria around 3.5 billion years
ago.               
                    -------Ken
Kinman