Definitions for "Allopatric Speciation"
(al´ lo pat´ rick) [Gr. allos: other + patria: fatherland] • Also called geographical speciation, this is the formation of two species from one when reproductive isolation occurs because of the the interposition of (or crossing of ) a physical geographic barrier such as a river. (Contrast with parapatric speciation, sympatric speciation.)
speciation in which the evolution of reproductive isolating mechanisms occurs during physical separation of the populations.
Speciation in which spatial isolation of populations precedes their differentiation (compare allochronic speciation).