To answer this question we need to remember some concepts, reproductive isolation is a phenomenon in which a population is isolated and cannot reproduce, this isolation can be due to a physical barrier or a genetic barrier, meanwhile, allopatry and sympatry are speciation mechanisms, this means that are processes of change among the populations and in both, reproductive isolation is involved, in the case of allopatry the barrier is physical, and in the case of sympatry, the barrier is genetic. So we can say that one is a phenomenon tha separates organisms meanwhile the others ar processes of change, therefore evolutive process