Allopatric Speciation describes why similar organisms do not interbreed because of a physical barrier.
Step-by-step explanation:
The specific situation in which the population of identical species doesn’t interbreed or leaves in isolation with each other is referred as ‘allopatric speciation’. It is also considered a specification of geographical factors.
The factors that work as a barrier to the process of breeding between same groups of organisms are- mountain formation, formation of water bodies, agriculture etc. These natural and human occurrences affect the geography of a place that influences the separation in species.