Point mutations can create changes in populations of organisms from the same species, but they lack the power to create and differentiate entire species. This more arduous work is left to larger mutations called genome rearrangements, which move around huge blocks of DNA. Rearrangements cause major genomic change, and most rearrangements are fatal or seriously damaging to the mutated cell and its descendants (many cancers derive from rearrangements). For this reason, rearrangements that come to influence the genome of an entire species are very rare.
Cenk Celik 