Re: Fwd: Re: birds DID NOT evolve from ther[o]pods

["Tim Williams" <tijawi@hotmail.com>]

Chip (Vorompatra@aol.com) wrote:

> << Go back to your cave, troll. >>
>
> Hey, wait a minute--he lives in a cave, has no respect for scientific
> credentials, has difficulty with English...I hate to go out on a limb here,
> but I think "Primal_dude" could be Taliban, venting anonymously in
> frustration at the first target that comes along...


Alas, I don't think we can blame the terrorists for this one.  I think I may 
have received messages from this guy(?) before (though under a different 
name).  I base this on the same bilious tone, garbled language, and 
recurrent theme as the previous messages.

"Primal Dude" forwarded me this today, sent to him from a listmember whom I 
have too much respect for to name here - and therefore further entangle in 
this nonsense.  (P.D. was citing it, I think, to convince me that he wasn't 
alone in disagreeing with me - though his language was hard to interpret):

> > I agree that the "Pouncing Proavis" hypothesis he [me] supports can't 
> > explain the evolution of the wing stroke, but could you be more specific?

The "Pouncing Proavis" model was proposed by Garner et al. (2000), and 
entails a proavian very similar to _Caudipteryx_.  The authors posit that 
the primordial wings were devices used by small coelurosaurs for 
maneuverability in short descents to the ground.  That much I agree with.  
However, I would contend that the primary selective force behind the 
development of the wing (i.e. the lengthening and planar structure of 
forelimb feathers) was lift, not drag (as Garner et al, posit) - and with a 
substantial thrust component as well.

Actually, I think my model of a tree-climbing ambush predator does explain 
the wingstroke: Small theropods leaped from trees and used the predatory 
stroke to grab prey on the ground.  (Perhaps this explains the more elevated 
glenoid as well?)  The fortuitous lift and thrust components became the 
foundation for further selection.  This is a "flapping start" model, but one 
which is gravity-assisted.


Tim




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