What evidence supports the theory of plate tectonics?

The theory of plate tectonics is supported by multiple lines of evidence that demonstrate how Earth's lithosphere is broken into tectonic plates that move and interact with one another. Among the strongest evidence are the distribution of fossils and geological formations.

Fossil distribution shows that similar species existed on continents that are now widely separated by oceans, suggesting that these landmasses were once connected. For example, fossils of the freshwater reptile Mesosaurus have been found in both South America and Africa, indicating these continents were once part of a larger landmass.

Additionally, geological formations, such as mountain ranges and rock types, provide further support. The Appalachian Mountains in North America align geologically with the Caledonian Mountains in Scotland, which supports the idea that these regions were once joined. The similarities in rock strata and age across different continents suggest they were part of a single landmass that has since drifted apart due to the movement of tectonic plates.

This combination of fossil evidence and geological correlation makes a compelling case for the theory of plate tectonics. Other options, such as the topography of ocean floors or volcanic activity alone, provide some support but do not encompass the breadth of evidence provided by both fossil distribution and geological formations.