Re: OCCAM'S RAZOR & THERIZINOSAURS

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

>In a message dated 98-08-02 15:06:12 EDT, cbrochu@fmppr.fmnh.org writes:
>
><< 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. >>
>
>I've read with comprehension every evolutionary hypothesis that relates
>dinosaurs and birds. BCF is the simplest and most straightforward. It has no
>problematic transformations at all. Some may have problems with BCF, but
>that's not because BCF is intrinsically problematic.

Actually, it has more to do with the fact that it requires a whole slew of
reversals.  I seem to recall a recent post of yours arguing that we should
prefer convergence over reversal every time, and yet strict interpretation
of BCF requires multiple reversals to a nonflying condition.  And the
number of required reversals is immense - this, by itself, renders it
nonparsimonious.

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