Why is sympatric speciation less likely to occur than allopatric speciation?

By definition, a sympatric speciation is a biological process wherein the evolution of a certain species most likely comes from their single ancestral species. Its main difference from the allopatric speciation is that the evolution does not necessary require to be physical in nature, therefore, it is most likely to occur less frequent.

What is the question? if you were looking to design a method of separating something, you can separate this compound by putting both in water and allowing the water to dissolve the sugar. then pour it into another beaker and evaporate it then boom! salt and sugar : ) 

A125feet i th answe