Step 1: Understanding Speciation Terms:
Allopatric Speciation: Speciation that occurs when biological populations of the same species become completely isolated from each other by a geographical barrier (like a mountain or ocean). (Allo = other, patric = land).
Sympatric Speciation: Speciation occurring within the same geographic area, often due to polyploidy or behavioral isolation.
Anagenesis: Phyletic evolution (gradual change of one species into another without splitting).
Cladogenesis: Splitting of one lineage into two.
Step 2: Final Answer:
Geographical isolation leads to Allopatric speciation.