[Taxacom] species (was: feathered flying fish)n
kennethkinman at webtv.net
Thu Mar 26 10:14:29 CDT 2009
That's an interesting twist on logic, which I
assume you meant to illustrate the absurdity of extreme "reductionist"
thinking (and the excesses of "cladification"). I capitalized the word
"just" in your response, because that one word makes a big difference
(as it also makes a difference in classifying Aves as "just" reptiles).
There are three major structural revolutions between us humans and our
(1) the eukaryotic cell (itself being a very
complex "colonial assemblage of symbiotic prokaryotes"); (2) assemblages
of eukaryotic cells into multicellular organisms; and (3) growth in size
and complexity of multicellular organisms (resulting in organs and organ
The first one (eukaryotic cell) resulted in a
huge increase in species cohesiveness, and the second made species even
more cohesive (and even less fuzzy). Therefore I cannot agree with the
conclusion that there are no species. Granted, they are still fuzzy, but
not nearly as fuzzy as species of unicellular protists (which have only
one main level of structural complexity beyond prokaryotes).
Conclusion. The most important kinds of complexity, be they
structural, or otherwise, are where paraphyletic cuts in the Tree of
Life are most useful (to both scholars and lay people). Prokaryota is
the ultimate paraphyletic taxon, and attempts to complete cladify it
(e.g., the Three Domain System) are often counterproductive.
We're all JUST colonial assemblages of symbiotic prokaryotes, serving as
an environment for other prokaryotes.
There are no species; only descendants.
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