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Re: soggy "down" maladaptive?
At 04:47 PM 27/04/01 +0000, Ken Kinman wrote:
Another argument put forward by Feduccia and others is that downy
feathers would be maladaptive as insulation (soggy feathers result in
hypothermia at night?) unless it was only on the young and a parent could
shield the young from getting its down wet.
How does one best argue against the "downy feathers get soggy and are
thus maladaptive" argument?
For one thing, I do not see its relevance. Whatever else the structures on
Sinosauropteryx, the new critter etc are, they are certainly not "down" in
the neornithine sense - ie a plumulaceous puff arising from a common
base. It may very well be true that a coat composed entirely of down might
be a problem for an adult - but who is claiming that there ever was such a
creature? In fact there seems (as far as I can see) no evidence that downy
underfeathers were present in non-avian dinos or even in Archaeopteryx;
they may have evolved at a later stage.
--
Ronald I. Orenstein Phone: (905) 820-7886
International Wildlife Coalition Fax/Modem: (905) 569-0116
1825 Shady Creek Court
Mississauga, Ontario, Canada L5L 3W2 mailto:ornstn@home.com