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Re: Yet more on dinosaur quad climbers



In a message dated 7/12/13 7:45:56 PM, biologyinmotion@gmail.com writes:

<< Yup, I wrote that, and I stand by it.  In fact, I'll go even further: 
flight feathers effectively must have originated in a non-flying context, or 
else the animals couldn't be aerial to begin with.  Now, it could be that the 
precursors to the derived flight feather state were used in a fluid force 
production context (i.e. lift and drag generators) before the advent of 
powered flight.  Under this sort of situation, we would predict that some kind 
of 
non-flight mobility behavior was present, and that additional changes in 
morphologies allowed a transition to full on aerial locomotion.  >>

This statement is confused in that it first says flight feathers must have 
originated in a non-flying context, but then says perhaps they evolved for 
aerodynamic purposes, which is inherently a flight context. It seems what is 
meant is powered flight context, but no one contests that pennaceous 
feathers evolved before that stage. 

I described in DA how pennaceous feathers could have evolved entirely in 
the context of developing flight from the very incipient stages all the way to 
full powered flight. Does not mean they had to have done that. Maybe they 
first evolved for display and were then co-opted for flight. Both modes seem 
viable. 

GSPaul

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