josbroek at EURONET.NL ("jos van den broek") writes:
>The complete genome of Methanococcus jannaschii reported in Science of
>23 August is another great achievement of Craig Venter c.s. According
>to Carl Woese it gives an extra proof of the fact that Archaea are
>closer related to Eukaryotes than to Bacteria. But not according to
>e.g. Margulis and Gupta, who now even stronger believe that Eukaryotes
>originated by a merger of archaebacteria and eubacteria. To my humble
>opinion they are right and Woese - although he's a great scientist -
>is wrong, and about to lose a paradigm... and a Kingdom.
Well, everyone is entitled to their opinion, but first you should
remind yourself that the goal of Margulis' current work is to bring
back the 19th century concept of five kingdoms (plants, animals,
fungi, protists, and monera), as proposed by Haekel. Unfortunately,
these kingdoms simply aren't defendable in the modern phylogenetic
context. No matter what your opinion is on the Archaea, there is no
way that one could logically consider protists as a monophyletic
group. Protists are merely defined by exclusion -- a eukaryote that
isn't a plant, animal, or fungus is called a protist. But this simply
doesn't make sense phylogenetically -- clearly at the very least
protists with mitrochrondia and those without arose from a different
evolutionary event. "Protist" simply isn't a biologically meaningful
group in any context whatsoever.
While I'm sure science will move on, and it is possible (although from
current data it seems unlikely) that the current three domain theory
will be proved incorrect, it seems pretty absurd to assume that the
scientific world would rush to embrace 19th century theories as its
replacement. It saddens me that Margulis, who was once a great
innovator with her theory of endosymbiosis, would have become such a
reactionary in her old age.
