Answer:
continental drift; different
Step-by-step explanation:
Continental Drift is a theory that states that one day, all the continents today were just one landmass called Pangeia. This supercontinent, thanks to the movement of the Tectonic Plates, has fragmented several times to give the present form of the earth masses.
This fragmentation provided a geographical separation of various plant and animal species. Each species began to change due to geographical isolation, natural selection and becoming anatomically and genetically different.