Re: flying Archie

["James R. Cunningham" <jrccea@bellsouth.net>]

Tim Williams wrote:

> I take your point.  However, I think it's a case of apples and oranges.
> _Archaeopteryx_'s style of flight was (presumably) very different to that of
> modern birds.

There doesn't appear to be any reason to think that.  For a model, just look at
modern birds of similar aspect ratio flying in a speed regime where the
supracoracoideus isn't a major asset (medium speed flight).

> I don't know why or how it flew, and we'll probably never
> know for sure.

There doesn't appear to be any reason to think that either.

>  However, there are probably many reasons why the modern
> avian body plan "took over" - associated with the ability to fly long
> distances, to better maneuver in flight,

Yes to the above.

> to catch prey on the wing, etc.

I wouldn't bet that Archie couldn't do that, if the opportunity and desire
arose.

> But _Archaeopteryx_ may not have needed any of these things.

Agreed.

>  Its style of
> flight was suitable for its limited purposes.

Why make the presumption that the purposes were limited?  I'd expect that the
purposes were well adapted to the needs of the animal.

>  Each to his own, I guess is
> what I'm saying.

I'd say that too.

> The other reason why I avoid terms like "inferior" and "superior" when
> discussing evolution is that it implies progress.  I know what you're
> getting at when you use these terms; but they do have baggage.

Well said.  Considerable baggage.

> Again, this is apples and oranges (or oranges and pomegranates).  Anyway,
> Archie's style may not even be "superior" to its predecessors.  For example,
> the microraptorans may exemplify one of the pre-_Archaeoptyeryx_ stages in
> the evolution of flight.  Although microraptoran taxonomy may currently be
> oversplit, microraptoran species are rather common in the Jehol biota.
> There may have been microraptoran-style gliders everwhere in the Early
> Cretaceous, and they may have outnumbered _Archaeopteryx_-style fliers.

Thanks for making this explicit.  It is often overlooked.  However, there is
still one presumtion present.  How about micro-raptoran style non-flying
flappers, or micro-raptoran flying flappers, or whatever, ad infinitum.... The
presumption being that these animals approached flying from gliding rather than
from enhancing terrestrial and arborial (sp??) maneuverability.  Neither
presumption has been proven yet.  Personally, I'm of the opinion that early
flying was an all of the above scenario.JimC