Re: OCCAM'S RAZOR & THERIZINOSAURS

[chris brochu <cbrochu@fmppr.fmnh.org>]

>In a message dated 98-08-02 13:59:30 EDT, cbrochu@fmppr.fmnh.org writes:
>
><< At present, the phylogenetic pattern recovered by multiple independent
> analyses over the past decade does not support secondary flightlessness.
> Secondary flightlessness is an additional assumption placed on the pattern
> a posteriori.  Is it a bad assumption?  Not necessarily - but it is
> secondary, and hence not parsimonious. >>
>
>Actually, secondary flightlessness is the simplest and most parsimonous way to
>describe the relationship between birds and theropod dinosaurs.



[List of features snipped]

Actually, this is precisely the thing that makes BCF an "umbrella
hypothesis."  Given the weight of *all available evidence*, BCF is not the
simplest explanation; but given a few transformations that might seem
problematic in isolation, BCF seems outwardly to fare better.



chris


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Christopher Brochu

Postdoctoral Research Scientist
Department of Geology
Field Museum of Natural History
Lake Shore Drive at Roosevelt Road
Chicago, IL  60605  USA

phone:  312-922-9410, ext. 469
fax:  312-922-9566

cbrochu@fmppr.fmnh.org