Cladistics and "Eclecticism"

[Thomas DiBenedetto]

-----Original Message-----
From: Hubert Turner
...to which internodon ("species") do the
two founder specimens belong? The parent or a descendant? If they
belong to the descendant, did they already belong to that descendant
before they migrated? Or have they changed taxon status after the
migration??
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The founder specimens belong to the parent taxon. And they belong to the
descendant taxon. When the founder specimens were born, they belonged only
to the parent taxon, and that taxon was a species-level taxon. When the
founder specimens founded the new taxon, they remain part of the parent
taxon, but that parent taxon now becomes a higher-level taxon. The newly
founded taxon originates as a species level taxon. So those specimens were
part of species X. And now they are part of higher taxon X and species Y.
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So, yesterday I was Homo sapiens, tomorrow I'll be on my way to Mars
and have changed specific status: I'll be Homo futuris or whatever??
This goes against all common sense and all rules of nomenclature. (Of
course the rules can be changed if necessary)
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I dont think that the fact that you are on your way to Mars makes the
difference, it is when you have reproduced and have offspring that are
permanently isolated from the sapiens that you left behind, that you can be
said to have founded a new taxon.
I dont see why it goes against common sense to recognize the fact that at
one point you were part of a terminal taxon, and that at a later point that
taxon is no longer terminal, and in addition, you are part of a new terminal
taxon.
NB. just because you are now part of futuris, does not mean you are no
longer sapiens. You be both.
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 If ten American couples and
ten Dutch couples go off to Mars to form a new "species", is that new
species monophyletic?
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Yes of course, American and Dutch couples are both parts of the same
species.
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 To me monophyletic is meaningless without
specifying the object and the level to which it pertains: A genus is
a monophyletic set of species (a common ancestor species and all its
descendant species), but a species is not necessarily a monophyletic
set of internodons, and certainly not a monophyletic set of
individuals (for sexually reproducing species this is impossible
anyway, because there is no single ancestral specimen to begin with!).
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I  think it overly reductionist to define monophyly in terms of individuals,
or even cells (as some have tried to do).  Species-level taxa are
monophyletic so long as one does not exclude any descendants, i.e.  they
correspond to a real lineage branch.