Polygenetic /(?)/

Pol·y·ge·net·ic

Polygenetic

a.
  1. Having many distinct sources; originating at various places or times.
  2. Of or pertaining to polygenesis; polyphyletic. (Biol.)

Phrases & Compounds
Polygenetic mountain range
one which is composite, or consists of two or more monogenetic ranges, each having had its own history of development.