hair, feathers.

[Earl Wood <candles@jps.net>]

     I would like to express my gratitude for the patience of this list
toward amateurs.
     The porcupine has both hair and quills, the quills are hollow as
are feathers, Is
there any evidence that quills and hair were evolved as a defense system
and then possibly to feathers ?
                                     Thank you all ,I am learning a
great deal..
     Earl