| Autor: |
Matthew Harris, Peter Dodson, Blair O. Wolf, Stuart S. Sumida, Paul K. Davis, Gopi K. Menon, Sam Tarsitano, Berry Pinshow, Nicholas R. Geist, John A. Ruben, Alan H. Brush, Warren P. Porter, Larry D. Martin, Phil Currie, Paul F. A. Maderson, Dominique G. Homberger, Lorenzo Alibardi, Roger H. Sawyer, Peter R. Stettenheim, Walter J. Bock, James O. Farlow |
| Rok vydání: |
2000 |
| Předmět: |
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| Zdroj: |
American Zoologist. 40:695-706 |
| ISSN: |
0003-1569 |
| DOI: |
10.1668/0003-1569(2000)040[0695:soeoof]2.0.co;2 |
| Popis: |
MADERSON: As Chairman, let me welcome you to the last portion of the symposium. My coorganizer Dominique (Homberger), and I had hoped that we could get this into an orderly fashion, but of course very few people cooperated! I will be working on an ad hoc basis from the very few written questions that have been submitted, but I am sure that topics will lead to one another. All of the speakers have their own microphones, and they may come down to the projector and scribble on overheads to make any point they wish. Will they please unplug their microphones before they move. If anyone from the audience, at any time, wishes to make comments, would they please move over to the central aisle and take up positions behind one of the three microphones. I will do my best to recognize them in an appropriate order relevant to the question that is being addressed by the panel speaker. I will start by reading a general question which is directed to Dominique (Homberger), Blair (Wolf) and Warren (Porter). Peter (Stettenheim) asks:—“Downy texture traps air, but is it any value for thermal insulation if there is not an outer, relatively impervious layer to keep the warm air in, or control its outflow? The analogy is that of a windshield over a warm sweater. Does this not suggest that early feathers must have had pennaceous vanes at least distally, if the downy bases, or down feathers, were to be effective for insulation? How does raising or lowering the feathers control heat loss or retention? Could this have been an additional role for depressing the feathers?” It sounds as if much of that question deals with controlled maneuverability (Maderson and Homberger, 2000), and perhaps Dominique (Homberger) would like to respond. HOMBERGER: I totally agree … |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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