Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? why or why not?

Geographical isolation would have more of an impact on speciation if it was an organism that reproduced sexually. If a positive mutation were to occur in an asexually reproducing organism that allowed it to survive better, evolution would be very sudden. There are many factors that can impact whether an organism is more fit and I do believe geographical differences can influence this. If the climate of an area suddenly drops but one organism can survive, they will pass their genes on and the rest will not.

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.