Re: The Evolutionary Mosaic (wasTrees Down or Ground Up?)

["Brian Lauret" <zthemanvirus@hotmail.com>]

Luis Rey wrote:

> Isn't the mosaic puzzle in turn a clear picture of evolution at work?  
> Following ground up reaching the tree heights or high canopy  gliding from 
> tree to tree strategies we are seeing a 'free-for all' set of strategies in 
> animals that were
> not absolutely specialized to what we call now sophisticated flight 'yet'. 
> At least some of them.
> Just as sifakas... arboreal but not flyers. Whatever  adaptation that helps 
> you to survive stays. And also as sifakas: I think there would be NO fully 
> formed feathers if (I'd say all) more primitive dinosaurs were not already 
> covered with
> a precursor of feathers that served as insulatory integument. Hats off to 
> Prum.
>
> None of these animals were compelled to become modern birds. But some of 
> these animals were already getting  fine tuned for extreme sophisticated 
> flight  adaptations and an absolute dependency on those...  and these were 
> to become the
> birds we know today, the rest went extinct.
Just what I think. I guess Mesozoic avian evolution was very messy with mass 
convergism,reversals and things unlike anything found in modern birds.The 
common ancestor must have been a very primitive creature wich descendants 
evolved in numerous ways,mostly getting more and more specialised for 
flight,but nearly as often evolving into something else. 
(dromaeosaurs,oviraptorosaurs,therezinosauroids,alvarezsaurs,patagopterygids,hesperornithids 
and whatever else might belong here..)

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