[Taxacom] Diversity of bacteria

brpatric at dwu.edu brpatric at dwu.edu
Wed Feb 8 08:42:04 CST 2012


Hi Ken et al.,

Okay, so Ken stated that the 3 domain system should be abandoned because
there seems to be more evidence that archaebacteria are indeed
monophyletic with eubacteria?  Thus, we should stay at the older
superkingdom system of Prokarya and Eukarya?

I am definitely NOT an expert on bacteria, so I am genuinely asking
whether this is a viable line of reasoning?  I thought that the evidence
for archaebacteria being more closely related to eukaryotes was pretty
strong (ribosomes of archaebacteria are more similar to eukaryotes and
other evidence that is not coming to mind at this moment).

What evidence exists for each side of this, i.e., for unifying all
prokaryotes into a single kingdom vs. the 3 domain system wherein the 2
superkingdom system creates paraphyly?

This is fascinating!  The paradigm shift to 3 domains was interesting,
but if there is now evidence to throw that into doubt for a return to
the previous paradigm...

Thanks again for your time!

Best regards, Brian

----------------------------------------------------------------
L. Brian Patrick, Ph.D.
Assistant Professor of Biology and Chair
Department of Biological Sciences
Dakota Wesleyan University
1200 W. University Ave.
Mitchell, SD  57301


-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu
[mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Dr.B.J.Tindall
Sent: Wednesday, February 08, 2012 1:35 AM
To: taxacom at mailman.nhm.ku.edu
Subject: Re: [Taxacom] Diversity of bacteria

Oh dear Ken,
"The Kingdom level taxa given at the LPSN website are those of Thomas
Cavalier-Smith, 2002 (the only person who has done so in compliance with
the Bacterial Code)."

The Code does not formally cover the nomenclature of anything above the
rank of class. As such none of the higher taxonomic names used in the
past or even at the present are covered by the Code and not all would be
listed on that website.

Minute 22 in:
http://ijs.sgmjournals.org/content/61/11/2775.full
that deals with the issue of names created by Cavalier-Smith.

There are other interpretations concerning the taxonomy of the higher
taxonomic ranks which differ from the opinion expressed by
Cavalier-Smith.

Traditionally the Code covered all "bacteria" that were not covered by
other Codes (cyanobacteria = cyanophytes are covered by the
International Code of Nomenclature for algae, fungi, and plants (ICN),
where they come under the category of "traditionally treated as
plants"). The 1990 revision of the Code is based on the 1975 revision,
which pre-dated the Eubacteria/Bacteria, Archae(o)bacteria/Archaea
concept (excluding of course Haeckel's class Bacteria and later Murray's
class Archaeobacteria). There are significant problems integrating names
of cyanobacteria/cyanophytes under the current Code due to differences
in the infrastructure of these two Codes.

Brian

Quoting Kenneth Kinman <kennethkinman at webtv.net>:

> Hi Brian,
>         The short answer is that the numbers do include
archaebacteria.
> The Kingdom level taxa given at the LPSN website are those of Thomas 
> Cavalier-Smith, 2002 (the only person who has done so in compliance 
> with the Bacterial Code).  He argues (and I think rightly so) that all

> prokaryotes should be classified as a single Kingdom Bacteria which he

> divides into two Subkingdoms (Negibacteria and Unibacteria).  In that 
> classification, the archaebacteria are included within Subkingdom 
> Unibacteria.
>
>        He (along with Ernst Mayr, and others) total reject the notion 
> that archaebacteria should be ranked as a separate "Domain" Archaea.
> Instead he has presented various lines of evidence that archaebacteria

> are sister group of a subclade of the Unibacteria.  Thus Woese's 
> Domain Bacteria is very paraphyletic with respect to Domain Archaea.  
> And Cavalier-Smith even believes that only the eubacteria existed for 
> the first 2 1/2 billion years of life, and that the archaebacteria 
> evolved from them less than a billion years ago.  That would make 
> Archaea an absurd misnomer.  Hopefully people will finally stop using 
> the Three Domain classification, and use Ernst Mayr's "Two Empire" 
> classification (Prokaryota and Eukaryota) as a more appropriate 
> division at the highest level.  As noted above, Cavalier-Smith's 
> Kingdom Bacteria is equivalent to Prokaryota.
>               ----------Ken Kinman
>






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