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--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 |