Continental Drift Theory was put forward by the German scientist Alfred Wegner in 1915.
According to the Continental Drift Theory, part of the crust are capable of horizontal movement round the globe causing the continents to slowly change their positions in relation to one another.
The fact that South America is a mirror image of Africa is presented as a proof of the continental drift theory (see video below for an animation showing the migration of both of these continents).
For hundreds of millions of years, all the land of Earth was joined together in one large mass or super continent. Scientists call it Pangaea (meaning “all lands” in Greek). Then about 200 million years ago the land began to drift apart. It broke into two pieces, and scientists have called the continent in the north Laurasia and the continent in the south Gondwanaland (named by Eduard Suess, an Austrian geologist). The two large continents continued to break apart into the smaller continents that exist today. Scientists call this movement ‘continental drift’.
Continental Drift: Africa and South America
A visualization showing the movement and rotation (but not deformation) of Africa and South America due to continental drift.