why we use beneck's broth medium for isolation and cultivation of algae from soil and water ,what is isolation

Dear student, algae cultural broth is recommended for isolation and cultivation of algae from soil and water because medium provides All necessary nutrients for good growth of algae. Geographical isolation is isolation of a species or a group of individuals from others by the means of some physical (geographical) barrier like river, mountain,big glacier etc. Geographical isolation results in evolution of new species. As the isolated species cannot mate with others because of isolation, it results in less no. of variations in the population. Thanks and regards