What is "polygenetic mountain range"

Polygenetic \Pol`y*ge*net"ic\, a.

1. Having many distinct sources; originating at various places or times.

2. (Biol.) Of or pertaining to polygenesis; polyphyletic.

   Polygenetic mountain range (Geol.), one which is composite, or consists of two or more monogenetic ranges, each having had its own history of development.
   --Dana.