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Most parsimious feathers



--Original Message-- From: Jonathan R. Wagner <znc14@TTACS.TTU.EDU>Date: 07
October 1998 17:33

>  AFAIK, parsimony is a method of structuring our reasoning on any number
of
scientific questions, based on the presumption that the correct answer is
inherent in the set of *all* of the data (a set which can never be
collected, but anyway...), and by chooseing the answer which "corresponds"
best to the data at hand, me make it more likely that our answer will be
closer to the truth. To deny this is to give up on ever finding a better
answer in science. Maybe I was wrong? :)
<

I hope so!


>  So, if therizinosaurs and birds are feathered, why can't their common
ancestor be feathered.

Therizinosaurs had dinofur, birds had proper feathers, and according to
parsimony, "our" philosophy requires that the common ancestor had one (or
both?!).  Perhaps it is not too unparsimonius to guess that:

     the bird and other maniraptoran explosion and the invention of the
feather are linked;

    everything descended from _Archae_ (ie birds & maniraptorans) were
feathered;

    nothing else was;

    other dinos had "fur" - and it would be parsimonius to assume that this
archosaur  type of fur was a feature they shared with pterosaurs (though not
mammals needless to say);

    the simplest explanation for dinofur and real feathers is that they are
homologous.  The alternative would be hard to prove, though we can learn
quite a lot from SEM's.


JJ