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Re: BCF ANDPDW



<<The miracle is in the accumulation of a >suite< of characters (not
just one or two but lots) in a non-flying, large, cursorial biped that
suddenly allows it to fly. It is emphatically not the evolution of 
flight itself. Did whales evolve flippers >before< they went into the 
water? No; it would be a miracle if they did. Then why would anyone 
think that birds evolved wings before they went into the air (became 
arboreal)? Yet this is just what the "ground up" paradigm maintains.>>

Mesonycid limbs were ancestrally built for walking and running, but this 
limb structure turned useful for swimming.  

<<Indeed; you've encapsulated BCF as well as anyone. As I said earlier, 
just good old evolution, proceeding one character at a time, over 
millions of years. But--in the "ground up" paradigm, there is no 
climbing, no gliding, no nothing before archaeopterygid flight. Big 
theropods six feet long or bigger simply ran around flapping their arms, 
and suddenly, like Peter Pan, they became small and could fly. This is 
the miracle.>>

Conversely you can argue that since climbing is unrelated to flight, 
then that is a miracle :-) 

The problem here is that I do not subscribe to BCF :-)  Yes, I can 
believe that birds came from arboreal ancestors, but does this mean that 
I subscibe to BCF?  No.  I do not believe that you can explain almost 
every single feature of dinosaurian evolution by the arboreal habits of 
the ancestral "dino/birds".  Plus, though I am VERY skeptical of the 
cursorial hypothesis, you are not giving the cursorial hypothesis its 
credit.  It is not arguing what you state.  It is arguing that the 
flight stroke evolved for predation and this predatory stroke became 
useful for aerodynamic stability.  As aerodynamics took a more primary 
role in the lives of the protoavians, they were selected for smaller 
size.  Regardless, I still do not believe the cursorial hypothesis.

Matt Troutman

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