The scientist who first proposed that the continents were once a whole was Alfred Wegener. Wegener was a German meteorologist and geophysicist who published his theory of continental drift in 1912.

He proposed that the continents had once been joined together in a single landmass, which he called "Pangaea". Pangaea began to break up about 200 million years ago, and the continents gradually drifted to their current positions.

Wegener's theory was not widely accepted until the 1960s, when new evidence from plate tectonics confirmed his basic idea. Today, continental drift is considered to be one of the most important theories in geology.