Re: Origin of feathers

[Dinogeorge <Dinogeorge@aol.com>]

In a message dated 98-04-28 02:37:07 EDT, Patrick.Norton@state.me.us writes:

<< Finally, it appears that those who accept the   
 "parachuting-gliding-flapping" origins of flight need to also explain how   
 the ancestors of Archaeopteryx evolved to the flapping stage (however   
 limited) with such an inadequate gliding design. Based on measurements   
 from a copy of the Berlin specimen of Archeopteryx, I estimate the aspect   
 ratio of A's wings at between 2 to 2.5. This is consistent with the   
 aspect ratio you get if you measure Paul's silhouette of Archaeopteryx in   
 PDW. From an aerodynamic perspective, aspect ratios in that range produce   
 a very low lift/drag ratio and therefore a fast sinking rate when   
 gliding. Volant birds in that range today compensate for a fast sinking   
 rate with powerful flapping.  IMHO, with a fast sinking rate and without   
 a powerful compensatory flapping ability, Archeopteryx must have perched   
 somewhat precariously. >>

You have forgotten about the feathered tail of _Archaeopteryx_, which
certainly provided lift and decreased the sinking rate.