Developed from the 1950s to the 1970s, the theory of plate tectonics is the modern update to continental drift, an idea first proposed by scientist Alfred Wegener in 1912 which stated that Earth's continents had “drifted” across the planet over time. Wegener proposed that the continents plowed through crust of ocean basins, which would explain why the outlines of many coastlines (like South America and Africa) look like they fit together like a puzzle.
