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Re: AT LAST!! Wing Assisted Incline Running (long)



Michael Skrepnick
Paleo Artist
Visit my Website:
http://www.dinosaursinart.com
----- Original Message -----
From: "Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>
To: "dinosaur" <dinosaur@usc.edu>
Sent: Thursday, January 16, 2003 3:46 PM
Subject: AT LAST!! Wing Assisted Incline Running (long)

> This demonstrates that there is a real benefit to a small but present
> enlargement of the wing feathers.  This suggests, further, that in an
animal
> engaged in running locomotion and with some feather-like integument (but
no
> true wing feathers) that there would be an advantage to those variants in
> the population which had slightly longer arm feathers than the rest of the
> population.  If arm feather length was a genetically-controlled trait,
then
> one has the conditions under which good old fashioned Darwinian selection
> could favor the increase in arm feather length in successive populations.

*** If this is true, then might you not also infer that there would be a
selective bias towards not only longer arm feather length, but the driving
force towards lengthening of arms (wings?) and digits in general.  More
appendicular length extending distally / laterally onto digit 2 translates
into more flat feather / wing surface area with which to generate energy /
traction into vertical climbing ability. Maybe trends towards longer
forelimb length in capturing prey as well as application in WAIR combined to
create a stronger evolutionary signal and further "push" those
characteristics.

Mike S.