Re: bauplan convergence

[Stanley Friesen <sarima@friesen.net>]

At 10:02 AM 6/15/00 -0700, Betty Cunningham wrote:
> I still put a vote behind the protofeather sexual display hopping thing
> for wing development; which is niether trees up or trees down, really.
> It makes more evolutionary sense to have a pre-flight-capable wing for
> making pretty, that later develops flight-worthiness, than a post-flight
> flipper developing flight-worthiness does...

I didn't say I thought it was viable - it just came closer than most other 
alternatives.

My own preferred *hypothetical* sequence is something like:
  1. Development of protofeathers for a combination of insulations and 
display.
     (essentially, self-reinforcing feedback), leading to:
  2. Enlarged display/brooding feathers on the arms.
  3. Development of a scansorial/arboreal lifestyle in a small form, allowing:
  4. Co-option of display feathers as a parachute/proto-wing.
  5. Elaboration of new function by natural selection for improved aerial
     safety/agility.

--------------
May the peace of God be with you.         sarima@ix.netcom.com