Re: PNAS

[Tim Williams <tijawi@yahoo.com>]

> From the article, it looks their beef is with the
> "ground-dwelling"
> parting, not so much the "theropod dinosaurs" part.


No, the "theropod dinosaurs" part gets dumped on too:


"...the newest PNAS research, Ruben said, are actually much more consistent 
with a different premise - that birds may have had an ancient common ancestor 
with dinosaurs, but they evolved separately on their own path..."


And I love this quote (from the article):


"This model was not consistent with successful flight from the ground up, and 
that makes it pretty difficult to make a case for a ground-dwelling theropod 
dinosaur to have developed wings and flown away," Ruben said. 


For some reason (as decreed by Ruben &c) evolution of flight must be either 
"ground-up" or "trees-down"; it could not incorporate both behaviors.  I've 
never believed in this "ground-up"-versus-"trees-down" dichotomy.  Why not?  
Because it's bullsh*t.


Many birds spend time on the ground, and spend time in trees as well.  In fact, 
such an ecology is quite common among extant bird species.  But for reasons 
that make no sense at all, some people (see above) claim that such an ecology 
is strictly prohibited for non-avian theropods.  They were either tree-dwelling 
gliders, or ground-dwelling cursors, but never both.  Like I said: Bullsh*t. 


And on it goes...


"On the other hand, it would have been quite possible for birds to have evolved 
and then, at some point, have various species lose their flight capabilities 
and become ground-dwelling, flightless animals - the raptors. This may be 
hugely upsetting to a lot of people, but it makes perfect sense."


Oooohhh... as toey as a Roman sandal.


Cheers

Tim 




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