Evidence for Plate Tectonics

The original conjectures concerning plate tectonics were based on circumstantial evidence like the shapes of continents being such that they would fit well if pushed together. Today, we have a much broader set of evidence in favor of the hypothesis.

Indications of Tectonic Activity

Among the classes of evidence for continental drift and the underlying plate tectonics we may list

1. The shapes of many continents are such that they look like they are separated pieces of a jig-saw puzzle. For example, look in the adjacent map at the shape of the east coast of North and South Americal relative to the shape of the west coast of Africa and Europe.

2. Many fossil comparisons along the edges of continents that look like they fit together suggest species similarities that would only make sense if the two continents were joined at some point in the past.