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Re: Why insulation = endothermy



Stan Friesen wrote:
>This whole issue is complicated by the fact that the development of
>flight and body feathers are probably governed by much the same genetic
>program.[...]
>Thus the structure of *modern* body feathers may be an indirect result
>of selection on the flight feathers.  In this case, even though
>body feathers may have preceded flight feathers, it is the latter
>that are determining the current shape of the former.
        I hate to sound like a broken record (pshah, you say... but let me
continue), but I would like to *again* refer folks to my posting on
Feduccia's "proof" that feathers developed for flight, evidenced by the
presence of the rachis.  It is in the dinolist archieves, and on my web
page.  Simple summary;
        Feduccia says that, because contour feather have rachi, and feathers
devolve into fuzzy bundles without rachi in flightless birds, feathers did
not develop for insulatory purposes, because "why would they have a rachis?"
        Easy response:  Because selection pressure related to flight causes
the contour feathers to develop, and retain, a rachis, and when this
pressure is removed (in flightless birds), the rachis may degenerate.
        Please consider this argument before you carry on with this course
of argument.  I do not believe that an argument of the complexity Stan poses
(no matter how good the argument is) is necessary to resolve this issue.
        Wagner

"Lord, bless this rocket-house, and all those who dwell within this
rocket-house."

        
+--------------------------------------------------------------------------+
| Jonathan R. Wagner                    "You can clade if you want to,     |
| Department of Geosciences              You can leave your friends behind |
| Texas Tech University                  Because your friends don't clade  |
| Lubbock, TX 79409                               and if they don't clade, |
|       *** wagner@ttu.edu ***           Then they're no friends of mine." |
|           Web Page:  http://faraday.clas.virginia.edu/~jrw6f             |
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