The formation of a new species by evolution or by any genetic modification of the previously existing species in a population is called speciation. Following are the factors that could lead to speciation: 1. Geographic isolation 2. Reproductive isolation 3. Genetic drift 4. Natural selection
Geographical isolation can not be a major factor in the speciation of a self-pollinating plant species. Since, the plants are self-pollinating, which means that the pollens are transferred from the anther of one flower to the stigma of the same flower or to the stigma of another flower of the same plant, geographical isolation cannot prevent speciation in this case.