Alfred Wegener was a German meteorologist who first proposed the theory of continental drift in 1912. Wegener's theory stated that the continents were once joined together in a single landmass called Pangaea, and that this landmass had since drifted apart.
Wegener's theory was based on several lines of evidence, including the remarkable fit between the coastlines of South America and Africa. When these coastlines are matched up, it is clear that they could have once been connected. This fit is so precise that some geologists have even suggested that the two continents were once separated by no more than a few hundred meters.
In addition to the fit between the coastlines of South America and Africa, Wegener also cited evidence from the distribution of fossils and geological features. For example, he found that fossils of the same plants and animals could be found on different continents, even though these continents were now separated by thousands of kilometers of ocean. This suggested that these continents had once been connected, and that the plants and animals had migrated between them.
Wegener's theory of continental drift was not widely accepted at first, but it has since been confirmed by a wealth of geological and paleontological evidence. Today, it is one of the most important and well-supported theories in the field of geology.