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Re: FLYING SQUIRRELS!



In a message dated 95-12-08 17:39:39 EST, ornstn@inforamp.net (Ronald
Orenstein) writes:

>I'm not sure of this.  Yes, flying squirrels are very diverse, but not
>particularly in relation to their gliding adaptations.  Rather than
>demonstrating a series of increasingly sophisticated adaptations you seem
>merely to have variations in size, thickness of pelage etc.  In other words,
>once a certain level in sophistication of gliding is reached the line tends
>to stay that way - another reason I find it difficult to see long-distance
>gliders as stages on the road to powered flight.

Yes, exactly. There would be no real _series_ of increasingly sophisticated
adaptations _within_ the mini-explosion. The diversity _itself_ fosters the
fortuitous appearance of the next stage. If there are just three or four
similar species of gliders (or whatever), it is much less likely that a
favorable evolutionary novelty would appear among one of them than if there
are, say, 50 or 100 similar species of gliders (or whatever), each on its own
particular track. So you have a mini-explosion, followed by essential stasis
until the next random breakthrough, then another mini-explosion, followed by
essental stasis until the next random breakthrough, and so forth.