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Re: birds scales



>Then again, it may mean exactly that.  To go out on a limb (and I think I
hear it snapping:-), since down is found mostly on chicks, this may show
that it is a primitive feature (based rather loosely on the principle of
neoteny).
>
>Rob

Presence of a character in a juvenile is not a good guide to a ancestral
state (otherwise you would have to assume that the ancestors of humans were
toothless and the ancestors of dogs had their eyes sealed shut!).

Secondly, it is not true that down is found "mostly on chicks".  It is just
that on chicks there are no normal contour feathers (megapodes excepted?);
their down is of a special type, called natal down..  A typical contour
feather is, in addition actually quite downy at the base.  For a famous
example of adult down consider eiderdown, plucked from the breasts of female
common eiders to line nests (and comforters, sleeping bags etc.).
--
Ronald I. Orenstein                           Phone: (905) 820-7886 (home)
International Wildlife Coalition              Fax/Modem: (905) 569-0116 (home)
Home: 1825 Shady Creek Court                  Messages: (416) 368-4661
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Toronto, Ontario Canada M5H 3P5