Jules Poirier lectures in British Columbia

WickedDyno amg39.REMOVETHIS at cornell.edu.invalid
Mon Sep 18 17:25:54 EDT 2000


In article <39c681a0_4 at news1.prserv.net>, scott at home.com wrote:

> In <8q44v4$g3b$1 at news.duke.edu>, mturner at snipthis.acpub.duke.edu (mel 
> turner) writes:
> >In article 
> ><amg39.REMOVETHIS-AAA43C.23363617092000 at newsstand.cit.cornell.edu>, 
> >amg39.REMOVETHIS at cornell.edu.invalid wrote...
> >>In article <39c58d4f_1 at news1.prserv.net>, scott at home.com wrote:
> >>> In 
> >>> <amg39.REMOVETHIS-62773D.21591816092000 at newsstand.cit.cornell.edu>, 
> >[snip]
> >
> >>> >> 14.Describe one insect that was transitional between a non-flying
> >>> >> insect and a flying insect.
> >>> >
> >>> >A gliding insect.
> >>> >
> >>> Amazing!
> >>> 
> >>> So not only is flying a convergent feature,
> >>> but so is the actual transition from gliding
> >>> to flying.
> >
> >How do you get "convergence" from that? As far as we know, flight in 
> >insects arose just once, in the early ancestors of the huge group 
> >Pterygota. He's just saying that the origin of insect flight would 
> >have involved a gliding intermediate stage [much as it would in the 
> >three separate origins of vertebrate flight]. 
> >
> That's my point.
> 
> Four separate origins of flight, and all
> arrived at by the exact same intermediate
> stage.  Amazing.

What other intermediate stage could there be?  If you don't quite have 
enough wing surface to fly, what can you do?  Well, glide, of course.  
And gliding is a useful adaptation.  Not quite as useful as true flight, 
in general, though.

-- 
|          Andrew Glasgow <amg39(at)cornell.edu>         |
| SCSI is *NOT* magic.  There are *fundamental technical |
| reasons* why it is necessary to sacrifice a young goat |
| to your SCSI chain now and then. -- John Woods         |


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