The continental drift theory is the theory that once all the continents were joined in a super-continent, which scientists call Pangaea. Over a vast period of time, the continents drifted apart to their current locations. Alfred Wegener first supported continental drift.
Wegener’s explanation of continental drift in 1912 was that drifting occurred because of the earth’s rotation. This explanation and his theory were not widely accepted. Prior to Wegener, however, many had noted that the shapes of the continents seem to fit together, suggesting some schism in the past.
Before the 1950s, the concept of the continental drift, for the most part, was not even entertained as plausible. In the 1950s and the years that followed, however, geologists began to consider the theory, and in the 1960s, most geologists came to accept that the theory may well be possible. Several factors point to the change in accepting the continental drift theory.
Fossil records from separate continents, particularly on the outskirts of continents show the same species. As well mineral specimens along the supposed break lines of the continents are nearly identical. Some identical species exist on certain continents, like an earthworm common to both Africa and South America suggesting the species could not have spontaneously arisen on both continents without some variations.
Continental drift theory also gained in popularity because of the theory of plate tectonics. Briefly, plate tectonics suggests that the ocean floor began to spread and that the continents existed on “plates” that moved in response to the changing ocean floor. Disruption in the continents, such as earthquakes, were a response to the moving plates. This suggests that certain points of the continents exhibit almost constant, though tiny, movements.
For example, Point Reyes, which is located on the San Andreas Fault line in Northern California, has been measured as slowly moving north at a rate of about half an inch (about 2.5 cm) per year. In fact, some geologists theorize that with continued movement, Point Reyes might eventually become an island.
Not everyone accepts the continental drift theory for many reasons. One reason for the dispute is that the age of the earth is in dispute. Some creationists, for example, believe that the earth is far younger than supposed some geologists believe. Some of these creationists also do not accept carbon dating as a way of determining earth, or fossil records being as old as some scientists claim.
Most scientists, and those not believing in creationism, accept the continental drift theory, along with the theory of plate tectonics. Those endorsing the theory of intelligent design usually accept continental drift as well, but assert that a spiritual presence designed and created the earth. Continental drift theory is now taught as accepted theory in public schools throughout the US.