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bats and dinosaurs



>Return-Path: dmcfarla@jsd.claremont.edu
>From: dmcfarla@jsd.claremont.edu
>Date: Thu, 22 Dec 1994 11:50:29 -0800
>To: ornstn@hookup.net
>Subject: bats and dinosaurs
>
>Ronald,
>          Regarding your posting on BATLINE, I don't think that what bats 
>do today (ie. hover, soar, roost on cave ceilings etc) is relevant. Clearly
>something as complex as powered flight couldn't evolve in one step - there
>had to be intermediate, non-powered stages. I don't know of any reasonable
>hypothesis for the origin of bat flight (regardless of whether it evolved 
>once or twice - c.f. the debate on whether Chiroptera is a monophyletic group)
>that doesn't invoke a gliding stage. Note that Dermopterans have very shallow
>glide paths, cover great distances, and apparently use gliding for regular
>'getting around' between feeding sites, not just predator escape. In the
>case of microchiropterans, I have no difficulty imagining an insectivorous
>gliding ancestor which used gliding to move between trees where in could 
>feed on large insects on leaves and trunks (many tropical insectivorous
>bats are foliage-gleaners). Catching insects on the wing involves additional
>specialization above and beyond the basic bat body plan, and almost certainly
>came later.
>       Incidentally, as someone who works on latest Quaternary extinctions
>(but therefore fossils nevertheless), I would be interested in details of
>subscribing to the dino list.
>
>                               Donald A. McFarlane
>                               Assistant Professor,
>                               The Claremont Colleges.
>
>
--
Ronald I. Orenstein                           Phone: (905) 820-7886 (home)
International Wildlife Coalition              Fax/Modem: (905) 569-0116 (home)
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