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Re: Campbell's even crazier than a MANIAC? (archeopteryx climbing)



> >> > I think its highly likely powered flight did
> not come
> >> before soaring.
> >>
> >> The fossil record points in the opposite
> direction: the
> >> bats still haven't got the idea of soaring,
> and the birds
> >> seem to only have evolved it after the Mesozoic
> was
> >> over. Even the pterosaurs started with small forms
> that
> >> didn't have particularly long wings.
> >
> > Well, we don't know if bats ever did soar at any
> point in the past, and I 
> > am specifically implying ridge soaring, not using
> thermals.
> 
> "Know" is too strong a word, but there's no
> evidence any bat ever soared, 
> neither direct nor phylogenetic nor even geographic.
> Ockham's Razor thus 
> argues against it.

well, that bat fossil record as far as I know has plenty of gaps where a bat 
could have been gliding, but as I already conceded for a variety of reasons, 
bats probably didn't take to soaring before flapping.

> 
> And how actually would soaring evolve into flapping?
> 

Well, if you have the minimum aerodynamic qualities to stay in the air in ridge 
lift (as archie or micro would have), you could get around along a ridge most 
of the time - evolving into a higher aspect ratio wing would allow a glider to 
get around faster, and soar in lighter winds, allowing it to get to whatever 
food it eats faster than its competitors.
Once a certain aspect ratio is reached, flapping probably would help, not 
hinder flight, if your a shore glider, and something washes up ou want to eat, 
and your gliding into a headwind, the ones that flaps gets there faster.
Flapping could start as a way to go upwind faster, cross a gap in the ridge, 
etc.
Keep in mind, suitable ridges may be less than 3 feet high for ridge soaring.


> The wings, at least, may well have become large enough for
> flight long 
> before flight started. That's because the wing feathers
> of birds may well 
> have evolved for brooding and/or display rather than any
> aerodynamic 
> function.

ok, well, display could just as easily take the form of tail plumage like is 
very common in birds nowadays, and would probably be less encumbering.
There is still no evidence for a display function.
I'm not quite sure how wings would be used in brooding....
But lets say the wings, for whatever non-flight reason, got big enough to be 
used in flight, the flapping behavior and muscles would still take time to 
evolve, whereas as soon as one of these winged but non flying ancestors made it 
to a suitable ridge, they would be able to fly quite a bit more than they ever 
could flapping at that stage.