[Taxacom] Dilemma of competing research programs in systematics

[John Grehan]

Since Jason brought up the issue about molecular systematics and phenetics
I thought I would comment further on this as a separate issue. My concern
is not so much whether molecular systematics may be phenetics (even though
I am inclined in that view) as it is over the question of contradictory
results between morphology (morphogenetics) and sequence morphology.

I ran into this conundrum with the human-great ape question, where if one
restricted derived characters states to those that are verified by outgroup
comparison (so only derived states shared by any combination of taxa within
the ingroup - i.e. large bodied apes) then one ended up with a
comparatively huge number of apomorphies supporting a human-orangutan clade
(for those unfamiliar with this, just for illustration - you can see this
in your face - forward facing cranial hair over forehead, forehead hair
microscopic length, same outer ear morphology, and for males - well
developed beard and mustache)

Of course this conflicts with all the molecular sequences studies have now
settled on a human-chimp clade. Within the sequence research program the
findings are considered robust given the large number of genes and
sequences etc.

So what is one supposed to do in this situation? One might say that the
morphological results are in error (the usual response) or one could say
the same about the molecular results.  In my case I see consistency in the
early hominids (australopiths) looking even more like orangutans and
retaining some orangutan apomorphies. But that's just my inclination and
others will of course not find that useful. Either way, there is no
independent umpire to make a decision. One can individually have an opinion
either way, but that does not resolve the contradiction. For now that is
what we are left with, no way to falsify one or the other.

John Grehan