So, all the continents can combine into a supercontinent we call Pangea. We believe Pangea was formed a long time ago. Because of different world events (earthquakes, fissures,ice melting, the meteor that hit the dinosaurs, etc)this supercontinent split and the continents drifted away eventually forming the modern day topography we know today. We have evidence that Pangea was formed a long time ago because of similar species on different continents that would be too far away to share a common ancestor otherwise. (think about birds being on every continent, they can't have flown all the way across the Atlantic/Pacific)
